5932 lines
302 KiB
XML
5932 lines
302 KiB
XML
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
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[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
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<chapter id='extendpoky'>
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<title>Common Tasks</title>
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<para>
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This chapter describes fundamental procedures such as creating layers,
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adding new software packages, extending or customizing images,
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porting work to new hardware (adding a new machine), and so forth.
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You will find the procedures documented here occur often in the
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develop cycle using the Yocto Project.
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</para>
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<section id="understanding-and-creating-layers">
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<title>Understanding and Creating Layers</title>
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<para>
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The OpenEmbedded build system supports organizing
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<link linkend='metadata'>Metadata</link> into multiple layers.
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Layers allow you to isolate different types of customizations from
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each other.
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You might find it tempting to keep everything in one layer when
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working on a single project.
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However, the more modular you organize your Metadata, the easier
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it is to cope with future changes.
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</para>
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<para>
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To illustrate how layers are used to keep things modular, consider
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machine customizations.
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These types of customizations typically reside in a special layer,
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rather than a general layer, called a Board Specific Package (BSP)
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Layer.
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Furthermore, the machine customizations should be isolated from
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recipes and Metadata that support a new GUI environment,
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for example.
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This situation gives you a couple of layers: one for the machine
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configurations, and one for the GUI environment.
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It is important to understand, however, that the BSP layer can
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still make machine-specific additions to recipes within the GUI
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environment layer without polluting the GUI layer itself
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with those machine-specific changes.
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You can accomplish this through a recipe that is a BitBake append
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(<filename>.bbappend</filename>) file, which is described later
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in this section.
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</para>
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<para>
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</para>
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<section id='yocto-project-layers'>
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<title>Layers</title>
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<para>
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The <link linkend='source-directory'>Source Directory</link>
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contains both general layers and BSP
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layers right out of the box.
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You can easily identify layers that ship with a
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Yocto Project release in the Source Directory by their
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folder names.
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Folders that are layers begin with the string
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<filename>meta</filename>.
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<note>
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It is not a requirement that a layer begins with the
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string <filename>meta</filename>.
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</note>
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For example, when you set up the Source Directory structure,
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you will see several layers:
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<filename>meta</filename>, <filename>meta-hob</filename>,
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<filename>meta-skeleton</filename>,
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<filename>meta-yocto</filename>, and
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<filename>meta-yocto-bsp</filename>.
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Each of these folders is a layer.
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</para>
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<para>
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Furthermore, if you set up a local copy of the
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<filename>meta-intel</filename> Git repository
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and then explore the folder of that general layer,
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you will discover many BSP layers inside.
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For more information on BSP layers, see the
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"<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-layers'>BSP Layers</ulink>"
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section in the Yocto Project Board Support Package (BSP)
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Developer's Guide.
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</para>
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</section>
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<section id='creating-your-own-layer'>
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<title>Creating Your Own Layer</title>
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<para>
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It is very easy to create your own layers to use with the
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OpenEmbedded build system.
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The Yocto Project ships with scripts that speed up creating
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general layers and BSP layers.
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This section describes the steps you perform by hand to create
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a layer so that you can better understand them.
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For information about the layer-creation scripts, see the
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"<ulink url='&YOCTO_DOCS_BSP_URL;#creating-a-new-bsp-layer-using-the-yocto-bsp-script'>Creating a New BSP Layer Using the yocto-bsp Script</ulink>"
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section in the Yocto Project Board Support Package (BSP)
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Developer's Guide and the
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"<link linkend='creating-a-general-layer-using-the-yocto-layer-script'>Creating a General Layer Using the yocto-layer Script</link>"
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section further down in this manual.
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</para>
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<para>
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Follow these general steps to create your layer:
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<orderedlist>
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<listitem><para><emphasis>Check Existing Layers:</emphasis>
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Before creating a new layer, you should be sure someone
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has not already created a layer containing the Metadata
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you need.
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You can see the
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<ulink url='http://layers.openembedded.org/layerindex/layers/'><filename>OpenEmbedded Metadata Index</filename></ulink>
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for a list of layers from the OpenEmbedded community
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that can be used in the Yocto Project.
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</para></listitem>
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<listitem><para><emphasis>Create a Directory:</emphasis>
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Create the directory for your layer.
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While not strictly required, prepend the name of the
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folder with the string <filename>meta-</filename>.
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For example:
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<literallayout class='monospaced'>
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meta-mylayer
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meta-GUI_xyz
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meta-mymachine
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</literallayout>
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</para></listitem>
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<listitem><para><emphasis>Create a Layer Configuration
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File:</emphasis>
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Inside your new layer folder, you need to create a
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<filename>conf/layer.conf</filename> file.
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It is easiest to take an existing layer configuration
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file and copy that to your layer's
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<filename>conf</filename> directory and then modify the
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file as needed.</para>
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<para>The
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<filename>meta-yocto-bsp/conf/layer.conf</filename> file
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demonstrates the required syntax:
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<literallayout class='monospaced'>
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# We have a conf and classes directory, add to BBPATH
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BBPATH .= ":${LAYERDIR}"
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# We have recipes-* directories, add to BBFILES
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BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
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${LAYERDIR}/recipes-*/*/*.bbappend"
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BBFILE_COLLECTIONS += "yoctobsp"
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BBFILE_PATTERN_yoctobsp = "^${LAYERDIR}/"
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BBFILE_PRIORITY_yoctobsp = "5"
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</literallayout></para>
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<para>Here is an explanation of the example:
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<itemizedlist>
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<listitem><para>The configuration and
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classes directory is appended to
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<ulink url='&YOCTO_DOCS_REF_URL;#var-BBPATH'><filename>BBPATH</filename></ulink>.
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<note>
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All non-distro layers, which include all BSP
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layers, are expected to append the layer
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directory to the
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<filename>BBPATH</filename>.
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On the other hand, distro layers, such as
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<filename>meta-yocto</filename>, can choose
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to enforce their own precedence over
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<filename>BBPATH</filename>.
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For an example of that syntax, see the
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<filename>layer.conf</filename> file for
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the <filename>meta-yocto</filename> layer.
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</note></para></listitem>
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<listitem><para>The recipes for the layers are
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appended to
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILES'>BBFILES</ulink></filename>.
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</para></listitem>
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<listitem><para>The
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILE_COLLECTIONS'>BBFILE_COLLECTIONS</ulink></filename>
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variable is then appended with the layer name.
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</para></listitem>
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<listitem><para>The
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILE_PATTERN'>BBFILE_PATTERN</ulink></filename>
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variable is set to a regular expression and is
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used to match files from
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<filename>BBFILES</filename> into a particular
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layer.
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In this case,
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-LAYERDIR'>LAYERDIR</ulink></filename>
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is used to make <filename>BBFILE_PATTERN</filename> match within the
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layer's path.</para></listitem>
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<listitem><para>The
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILE_PRIORITY'>BBFILE_PRIORITY</ulink></filename>
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variable then assigns a priority to the layer.
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Applying priorities is useful in situations
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where the same package might appear in multiple
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layers and allows you to choose what layer
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should take precedence.</para></listitem>
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</itemizedlist></para>
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<para>Note the use of the
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-LAYERDIR'>LAYERDIR</ulink></filename>
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variable, which expands to the directory of the current
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layer.</para>
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<para>Through the use of the <filename>BBPATH</filename>
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variable, BitBake locates <filename>.bbclass</filename>
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files, configuration files, and files that are included
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with <filename>include</filename> and
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<filename>require</filename> statements.
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For these cases, BitBake uses the first file that
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matches the name found in <filename>BBPATH</filename>.
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This is similar to the way the <filename>PATH</filename>
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variable is used for binaries.
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We recommend, therefore, that you use unique
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<filename>.bbclass</filename> and configuration
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filenames in your custom layer.</para></listitem>
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<listitem><para><emphasis>Add Content:</emphasis> Depending
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on the type of layer, add the content.
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If the layer adds support for a machine, add the machine
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configuration in a <filename>conf/machine/</filename>
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file within the layer.
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If the layer adds distro policy, add the distro
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configuration in a <filename>conf/distro/</filename>
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file with the layer.
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If the layer introduces new recipes, put the recipes
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you need in <filename>recipes-*</filename>
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subdirectories within the layer.
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<note>In order to be compliant with the Yocto Project,
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a layer must contain a
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<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-filelayout-readme'>README file.</ulink>
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</note></para></listitem>
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</orderedlist>
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</para>
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</section>
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<section id='best-practices-to-follow-when-creating-layers'>
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<title>Best Practices to Follow When Creating Layers</title>
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<para>
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To create layers that are easier to maintain and that will
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not impact builds for other machines, you should consider the
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information in the following sections.
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</para>
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<section id='avoid-overlaying-entire-recipes'>
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<title>Avoid "Overlaying" Entire Recipes</title>
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<para>
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Avoid "overlaying" entire recipes from other layers in your
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configuration.
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In other words, do not copy an entire recipe into your
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layer and then modify it.
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Use <filename>.bbappend</filename> files to override the
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parts of the recipe you need to modify.
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</para>
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</section>
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<section id='avoid-duplicating-include-files'>
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<title>Avoid Duplicating Include Files</title>
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<para>
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Avoid duplicating include files.
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Use <filename>.bbappend</filename> files for each recipe
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that uses an include file.
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Or, if you are introducing a new recipe that requires
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the included file, use the path relative to the original
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layer directory to refer to the file.
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For example, use
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<filename>require recipes-core/somepackage/somefile.inc</filename>
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instead of <filename>require somefile.inc</filename>.
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If you're finding you have to overlay the include file,
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it could indicate a deficiency in the include file in
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the layer to which it originally belongs.
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If this is the case, you need to address that deficiency
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instead of overlaying the include file.
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For example, consider how support plug-ins for the Qt 4
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database are configured.
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The Source Directory does not have MySQL or PostgreSQL.
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However, OpenEmbedded's layer <filename>meta-oe</filename>
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does.
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Consequently, <filename>meta-oe</filename> uses
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<filename>.bbappend</filename> files to modify the
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<filename>QT_SQL_DRIVER_FLAGS</filename> variable to
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enable the appropriate plug-ins.
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This variable was added to the <filename>qt4.inc</filename>
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include file in the Source Directory specifically to allow
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the <filename>meta-oe</filename> layer to be able to control
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which plug-ins are built.
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</para>
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</section>
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<section id='structure-your-layers'>
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<title>Structure Your Layers</title>
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<para>
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Proper use of overrides within append files and placement
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of machine-specific files within your layer can ensure that
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a build is not using the wrong Metadata and negatively
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impacting a build for a different machine.
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Following are some examples:
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<itemizedlist>
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<listitem><para><emphasis>Modifying Variables to support
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a different machine:</emphasis>
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Suppose you have a layer named
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<filename>meta-one</filename> that adds support
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for building machine "one".
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To do so, you use an append file named
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<filename>base-files.bbappend</filename> and
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create a dependency on "foo" by altering the
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<ulink url='&YOCTO_DOCS_REF_URL;#var-DEPENDS'><filename>DEPENDS</filename></ulink>
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variable:
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<literallayout class='monospaced'>
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DEPENDS = "foo"
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</literallayout>
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The dependency is created during any build that
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includes the layer
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<filename>meta-one</filename>.
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However, you might not want this dependency
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for all machines.
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For example, suppose you are building for
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machine "two" but your
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<filename>bblayers.conf</filename> file has the
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<filename>meta-one</filename> layer included.
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During the build, the
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<filename>base-files</filename> for machine
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"two" will also have the dependency on
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<filename>foo</filename>.</para>
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<para>To make sure your changes apply only when
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building machine "one", use a machine override
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with the <filename>DEPENDS</filename> statement:
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<literallayout class='monospaced'>
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DEPENDS_one = "foo"
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</literallayout>
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You should follow the same strategy when using
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<filename>_append</filename> and
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<filename>_prepend</filename> operations:
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<literallayout class='monospaced'>
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DEPENDS_append_one = " foo"
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DEPENDS_prepend_one = "foo "
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</literallayout>
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<note>
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Avoiding "+=" and "=+" and using
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machine-specific
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<filename>_append</filename>
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and <filename>_prepend</filename> operations
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is recommended as well.
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</note></para></listitem>
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<listitem><para><emphasis>Place Machine-Specific Files
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in Machine-Specific Locations:</emphasis>
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When you have a base recipe, such as
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<filename>base-files.bb</filename>, that
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contains a
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<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
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statement to a file, you can use an append file
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to cause the build to use your own version of
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the file.
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For example, an append file in your layer at
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<filename>/meta-one/recipes-core/base-files/base-files.bbappend</filename>
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could extend
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<ulink url='&YOCTO_DOCS_REF_URL;#var-FILESPATH'><filename>FILESPATH</filename></ulink>
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using
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<ulink url='&YOCTO_DOCS_REF_URL;#var-FILESEXTRAPATHS'><filename>FILESEXTRAPATHS</filename></ulink>
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as follows:
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<literallayout class='monospaced'>
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FILESEXTRAPATHS_prepend := "${THISDIR}/${BPN}:"
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</literallayout>
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The build for machine "one" will pick up your
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machine-specific file as long as you have the
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file in
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<filename>/meta-one/recipes-core/base-files/base-files/</filename>.
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However, if you are building for a different
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machine and the
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<filename>bblayers.conf</filename> file includes
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the <filename>meta-one</filename> layer and
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the location of your machine-specific file is
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the first location where that file is found
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according to <filename>FILESPATH</filename>,
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builds for all machines will also use that
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machine-specific file.</para>
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<para>You can make sure that a machine-specific
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file is used for a particular machine by putting
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the file in a subdirectory specific to the
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machine.
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For example, rather than placing the file in
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<filename>/meta-one/recipes-core/base-files/base-files/</filename>
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as shown above, put it in
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<filename>/meta-one/recipes-core/base-files/base-files/one/</filename>.
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Not only does this make sure the file is used
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only when building for machine "one" but the
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build process locates the file more quickly.</para>
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<para>In summary, you need to place all files
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referenced from <filename>SRC_URI</filename>
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in a machine-specific subdirectory within the
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layer in order to restrict those files to
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machine-specific builds.</para></listitem>
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</itemizedlist>
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</para>
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</section>
|
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<section id='other-recommendations'>
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<title>Other Recommendations</title>
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<para>
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We also recommend the following:
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<itemizedlist>
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<listitem><para>Store custom layers in a Git repository
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that uses the
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<filename>meta-<layer_name></filename> format.
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</para></listitem>
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<listitem><para>Clone the repository alongside other
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<filename>meta</filename> directories in the
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<link linkend='source-directory'>Source Directory</link>.
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</para></listitem>
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</itemizedlist>
|
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Following these recommendations keeps your Source Directory and
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its configuration entirely inside the Yocto Project's core
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base.
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</para>
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</section>
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</section>
|
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|
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<section id='enabling-your-layer'>
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<title>Enabling Your Layer</title>
|
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|
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<para>
|
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Before the OpenEmbedded build system can use your new layer,
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you need to enable it.
|
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To enable your layer, simply add your layer's path to the
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<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BBLAYERS'>BBLAYERS</ulink></filename>
|
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variable in your <filename>conf/bblayers.conf</filename> file,
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which is found in the
|
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<link linkend='build-directory'>Build Directory</link>.
|
|
The following example shows how to enable a layer named
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<filename>meta-mylayer</filename>:
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<literallayout class='monospaced'>
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LCONF_VERSION = "6"
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BBPATH = "${TOPDIR}"
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BBFILES ?= ""
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BBLAYERS ?= " \
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$HOME/poky/meta \
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$HOME/poky/meta-yocto \
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$HOME/poky/meta-yocto-bsp \
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$HOME/poky/meta-mylayer \
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"
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BBLAYERS_NON_REMOVABLE ?= " \
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$HOME/poky/meta \
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$HOME/poky/meta-yocto \
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"
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</literallayout>
|
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</para>
|
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|
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<para>
|
|
BitBake parses each <filename>conf/layer.conf</filename> file
|
|
as specified in the <filename>BBLAYERS</filename> variable
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|
within the <filename>conf/bblayers.conf</filename> file.
|
|
During the processing of each
|
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<filename>conf/layer.conf</filename> file, BitBake adds the
|
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recipes, classes and configurations contained within the
|
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particular layer to the source directory.
|
|
</para>
|
|
</section>
|
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|
|
<section id='using-bbappend-files'>
|
|
<title>Using .bbappend Files</title>
|
|
|
|
<para>
|
|
Recipes used to append Metadata to other recipes are called
|
|
BitBake append files.
|
|
BitBake append files use the <filename>.bbappend</filename> file
|
|
type suffix, while the corresponding recipes to which Metadata
|
|
is being appended use the <filename>.bb</filename> file type
|
|
suffix.
|
|
</para>
|
|
|
|
<para>
|
|
A <filename>.bbappend</filename> file allows your layer to make
|
|
additions or changes to the content of another layer's recipe
|
|
without having to copy the other recipe into your layer.
|
|
Your <filename>.bbappend</filename> file resides in your layer,
|
|
while the main <filename>.bb</filename> recipe file to
|
|
which you are appending Metadata resides in a different layer.
|
|
</para>
|
|
|
|
<para>
|
|
Append files must have the same root names as their corresponding
|
|
recipes.
|
|
For example, the append file
|
|
<filename>someapp_&DISTRO;.bbappend</filename> must apply to
|
|
<filename>someapp_&DISTRO;.bb</filename>.
|
|
This means the original recipe and append file names are version
|
|
number-specific.
|
|
If the corresponding recipe is renamed to update to a newer
|
|
version, the corresponding <filename>.bbappend</filename> file must
|
|
be renamed as well.
|
|
During the build process, BitBake displays an error on starting
|
|
if it detects a <filename>.bbappend</filename> file that does
|
|
not have a corresponding recipe with a matching name.
|
|
See the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BB_DANGLINGAPPENDS_WARNONLY'><filename>BB_DANGLINGAPPENDS_WARNONLY</filename></ulink>
|
|
variable for information on how to handle this error.
|
|
</para>
|
|
|
|
<para>
|
|
Being able to append information to an existing recipe not only
|
|
avoids duplication, but also automatically applies recipe
|
|
changes in a different layer to your layer.
|
|
If you were copying recipes, you would have to manually merge
|
|
changes as they occur.
|
|
</para>
|
|
|
|
<para>
|
|
As an example, consider the main formfactor recipe and a
|
|
corresponding formfactor append file both from the
|
|
<link linkend='source-directory'>Source Directory</link>.
|
|
Here is the main formfactor recipe, which is named
|
|
<filename>formfactor_0.0.bb</filename> and located in the
|
|
"meta" layer at
|
|
<filename>meta/recipes-bsp/formfactor</filename>:
|
|
<literallayout class='monospaced'>
|
|
DESCRIPTION = "Device formfactor information"
|
|
SECTION = "base"
|
|
LICENSE = "MIT"
|
|
LIC_FILES_CHKSUM = "file://${COREBASE}/LICENSE;md5=3f40d7994397109285ec7b81fdeb3b58 \
|
|
file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
|
|
PR = "r21"
|
|
|
|
SRC_URI = "file://config file://machconfig"
|
|
S = "${WORKDIR}"
|
|
|
|
PACKAGE_ARCH = "${MACHINE_ARCH}"
|
|
INHIBIT_DEFAULT_DEPS = "1"
|
|
|
|
do_install() {
|
|
# Only install file if it has a contents
|
|
install -d ${D}${sysconfdir}/formfactor/
|
|
install -m 0644 ${S}/config ${D}${sysconfdir}/formfactor/
|
|
if [ -s "${S}/machconfig" ]; then
|
|
install -m 0644 ${S}/machconfig ${D}${sysconfdir}/formfactor/
|
|
fi
|
|
} </literallayout>
|
|
In the main recipe, note the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
variable, which tells the OpenEmbedded build system where to
|
|
find files during the build.
|
|
</para>
|
|
|
|
<para>
|
|
Following is the append file, which is named
|
|
<filename>formfactor_0.0.bbappend</filename> and is from the
|
|
Crown Bay BSP Layer named
|
|
<filename>meta-intel/meta-crownbay</filename>.
|
|
The file is in <filename>recipes-bsp/formfactor</filename>:
|
|
<literallayout class='monospaced'>
|
|
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
|
|
|
|
PRINC := "${@int(PRINC) + 2}"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
By default, the build system uses the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-FILESPATH'><filename>FILESPATH</filename></ulink>
|
|
variable to locate files.
|
|
This append file extends the locations by setting the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-FILESEXTRAPATHS'><filename>FILESEXTRAPATHS</filename></ulink>
|
|
variable.
|
|
Setting this variable in the <filename>.bbappend</filename>
|
|
file is the most reliable and recommended method for adding
|
|
directories to the search path used by the build system
|
|
to find files.
|
|
</para>
|
|
|
|
<para>
|
|
The statement in this example extends the directories to include
|
|
<filename>${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-THISDIR'><filename>THISDIR</filename></ulink><filename>}/${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PN'><filename>PN</filename></ulink><filename>}</filename>,
|
|
which resolves to a directory named
|
|
<filename>formfactor</filename> in the same directory
|
|
in which the append file resides (i.e.
|
|
<filename>meta-intel/meta-crownbay/recipes-bsp/formfactor/formfactor</filename>.
|
|
This implies that you must have the supporting directory
|
|
structure set up that will contain any files or patches you
|
|
will be including from the layer.
|
|
</para>
|
|
|
|
<para>
|
|
Using the immediate expansion assignment operator
|
|
<filename>:=</filename> is important because of the reference to
|
|
<filename>THISDIR</filename>.
|
|
The trailing colon character is important as it ensures that
|
|
items in the list remain colon-separated.
|
|
<note><para>BitBake automatically defines the
|
|
<filename>THISDIR</filename> variable.
|
|
You should never set this variable yourself.
|
|
Using <filename>_prepend</filename> ensures your path will
|
|
be searched prior to other paths in the final list.</para>
|
|
<para>Also, not all append files add extra files.
|
|
Many append files simply exist to add build options
|
|
(e.g. <filename>systemd</filename>).
|
|
For these cases, it is not necessary to use the
|
|
"_prepend" part of the statement.</para>
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='prioritizing-your-layer'>
|
|
<title>Prioritizing Your Layer</title>
|
|
|
|
<para>
|
|
Each layer is assigned a priority value.
|
|
Priority values control which layer takes precedence if there
|
|
are recipe files with the same name in multiple layers.
|
|
For these cases, the recipe file from the layer with a higher
|
|
priority number takes precedence.
|
|
Priority values also affect the order in which multiple
|
|
<filename>.bbappend</filename> files for the same recipe are
|
|
applied.
|
|
You can either specify the priority manually, or allow the
|
|
build system to calculate it based on the layer's dependencies.
|
|
</para>
|
|
|
|
<para>
|
|
To specify the layer's priority manually, use the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILE_PRIORITY'><filename>BBFILE_PRIORITY</filename></ulink>
|
|
variable.
|
|
For example:
|
|
<literallayout class='monospaced'>
|
|
BBFILE_PRIORITY_mylayer = "1"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<note>
|
|
<para>It is possible for a recipe with a lower version number
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PV'><filename>PV</filename></ulink>
|
|
in a layer that has a higher priority to take precedence.</para>
|
|
<para>Also, the layer priority does not currently affect the
|
|
precedence order of <filename>.conf</filename>
|
|
or <filename>.bbclass</filename> files.
|
|
Future versions of BitBake might address this.</para>
|
|
</note>
|
|
</section>
|
|
|
|
<section id='managing-layers'>
|
|
<title>Managing Layers</title>
|
|
|
|
<para>
|
|
You can use the BitBake layer management tool to provide a view
|
|
into the structure of recipes across a multi-layer project.
|
|
Being able to generate output that reports on configured layers
|
|
with their paths and priorities and on
|
|
<filename>.bbappend</filename> files and their applicable
|
|
recipes can help to reveal potential problems.
|
|
</para>
|
|
|
|
<para>
|
|
Use the following form when running the layer management tool.
|
|
<literallayout class='monospaced'>
|
|
$ bitbake-layers <command> [arguments]
|
|
</literallayout>
|
|
The following list describes the available commands:
|
|
<itemizedlist>
|
|
<listitem><para><filename><emphasis>help:</emphasis></filename>
|
|
Displays general help or help on a specified command.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>show-layers:</emphasis></filename>
|
|
Shows the current configured layers.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>show-recipes:</emphasis></filename>
|
|
Lists available recipes and the layers that provide them.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>show-overlayed:</emphasis></filename>
|
|
Lists overlayed recipes.
|
|
A recipe is overlayed when a recipe with the same name
|
|
exists in another layer that has a higher layer
|
|
priority.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>show-appends:</emphasis></filename>
|
|
Lists <filename>.bbappend</filename> files and the
|
|
recipe files to which they apply.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>show-cross-depends:</emphasis></filename>
|
|
Lists dependency relationships between recipes that
|
|
cross layer boundaries.
|
|
</para></listitem>
|
|
<listitem><para><filename><emphasis>flatten:</emphasis></filename>
|
|
Flattens the layer configuration into a separate output
|
|
directory.
|
|
Flattening your layer configuration builds a "flattened"
|
|
directory that contains the contents of all layers,
|
|
with any overlayed recipes removed and any
|
|
<filename>.bbappend</filename> files appended to the
|
|
corresponding recipes.
|
|
You might have to perform some manual cleanup of the
|
|
flattened layer as follows:
|
|
<itemizedlist>
|
|
<listitem><para>Non-recipe files (such as patches)
|
|
are overwritten.
|
|
The flatten command shows a warning for these
|
|
files.
|
|
</para></listitem>
|
|
<listitem><para>Anything beyond the normal layer
|
|
setup has been added to the
|
|
<filename>layer.conf</filename> file.
|
|
Only the lowest priority layer's
|
|
<filename>layer.conf</filename> is used.
|
|
</para></listitem>
|
|
<listitem><para>Overridden and appended items from
|
|
<filename>.bbappend</filename> files need to be
|
|
cleaned up.
|
|
The contents of each
|
|
<filename>.bbappend</filename> end up in the
|
|
flattened recipe.
|
|
However, if there are appended or changed
|
|
variable values, you need to tidy these up
|
|
yourself.
|
|
Consider the following example.
|
|
Here, the <filename>bitbake-layers</filename>
|
|
command adds the line
|
|
<filename>#### bbappended ...</filename> so that
|
|
you know where the following lines originate:
|
|
<literallayout class='monospaced'>
|
|
...
|
|
DESCRIPTION = "A useful utility"
|
|
...
|
|
EXTRA_OECONF = "--enable-something"
|
|
...
|
|
|
|
#### bbappended from meta-anotherlayer ####
|
|
|
|
DESCRIPTION = "Customized utility"
|
|
EXTRA_OECONF += "--enable-somethingelse"
|
|
</literallayout>
|
|
Ideally, you would tidy up these utilities as
|
|
follows:
|
|
<literallayout class='monospaced'>
|
|
...
|
|
DESCRIPTION = "Customized utility"
|
|
...
|
|
EXTRA_OECONF = "--enable-something --enable-somethingelse"
|
|
...
|
|
</literallayout></para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='creating-a-general-layer-using-the-yocto-layer-script'>
|
|
<title>Creating a General Layer Using the yocto-layer Script</title>
|
|
|
|
<para>
|
|
The <filename>yocto-layer</filename> script simplifies
|
|
creating a new general layer.
|
|
<note>
|
|
For information on BSP layers, see the
|
|
"<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-layers'>BSP Layers</ulink>"
|
|
section in the Yocto Project Board Specific (BSP)
|
|
Developer's Guide.
|
|
</note>
|
|
The default mode of the script's operation is to prompt you for
|
|
information needed to generate the layer:
|
|
<itemizedlist>
|
|
<listitem><para>The layer priority
|
|
</para></listitem>
|
|
<listitem><para>Whether or not to create a sample recipe.
|
|
</para></listitem>
|
|
<listitem><para>Whether or not to create a sample
|
|
append file.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Use the <filename>yocto-layer create</filename> sub-command
|
|
to create a new general layer.
|
|
In its simplest form, you can create a layer as follows:
|
|
<literallayout class='monospaced'>
|
|
$ yocto-layer create mylayer
|
|
</literallayout>
|
|
The previous example creates a layer named
|
|
<filename>meta-mylayer</filename> in the current directory.
|
|
</para>
|
|
|
|
<para>
|
|
As the <filename>yocto-layer create</filename> command runs,
|
|
default values for the prompts appear in brackets.
|
|
Pressing enter without supplying anything for the prompts
|
|
or pressing enter and providing an invalid response causes the
|
|
script to accept the default value.
|
|
Once the script completes, the new layer
|
|
is created in the current working directory.
|
|
The script names the layer by prepending
|
|
<filename>meta-</filename> to the name you provide.
|
|
</para>
|
|
|
|
<para>
|
|
Minimally, the script creates the following within the layer:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>The <filename>conf</filename>
|
|
directory:</emphasis>
|
|
This directory contains the layers
|
|
<filename>.conf</filename>.
|
|
The root name for the file is the same as the root name
|
|
your provided for the layer.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>The
|
|
<filename>COPYING.MIT</filename>:</emphasis>
|
|
The copyright and use notice for the software.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>The <filename>README</filename>
|
|
file:</emphasis>
|
|
A file describing the contents of your new layer.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
If you choose to generate a sample recipe file, the script
|
|
prompts you for the name for the recipe and then creates it
|
|
in <filename><layer>/recipes-example/example/</filename>.
|
|
in a directory named <filename>recipes-example</filename>.
|
|
The script creates a <filename>.bb</filename> file and a
|
|
directory, which contains a sample
|
|
<filename>helloworld.c</filename> source file and along with
|
|
a sample patch file.
|
|
If you do not provide a recipe name, the script uses
|
|
"example".
|
|
</para>
|
|
|
|
<para>
|
|
If you choose to generate a sample append file, the script
|
|
prompts you for the name for the file and then creates it
|
|
in <filename><layer>/recipes-example-bbappend/example-bbappend/</filename>.
|
|
The script creates a <filename>.bbappend</filename> file and a
|
|
directory, which contains a sample patch file.
|
|
If you do not provide a recipe name, the script uses
|
|
"example".
|
|
The script also prompts you for the version of the append file.
|
|
The version should match the recipe to which the append file
|
|
is associated.
|
|
</para>
|
|
|
|
<para>
|
|
The easiest way to see how the <filename>yocto-layer</filename>
|
|
script works is to experiment with the script.
|
|
You can also read the usage information by entering the
|
|
following:
|
|
<literallayout class='monospaced'>
|
|
$ yocto-layer help
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
Once you create your general layer, you must add it to your
|
|
<filename>bblayers.conf</filename> file.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
BBLAYERS = ?" \
|
|
/usr/local/src/yocto/meta \
|
|
/usr/local/src/yocto/meta-yocto \
|
|
/usr/local/src/yocto/meta-yocto-bsp \
|
|
/usr/local/src/yocto/meta-mylayer \
|
|
"
|
|
|
|
BBLAYERS_NON_REMOVABLE ?= " \
|
|
/usr/local/src/yocto/meta \
|
|
/usr/local/src/yocto/meta-yocto \
|
|
"
|
|
</literallayout>
|
|
Adding the layer to this file enables the build system to
|
|
locate the layer during the build.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-customimage'>
|
|
<title>Customizing Images</title>
|
|
|
|
<para>
|
|
You can customize images to satisfy particular requirements.
|
|
This section describes several methods and provides guidelines for each.
|
|
</para>
|
|
|
|
<section id='usingpoky-extend-customimage-custombb'>
|
|
<title>Customizing Images Using Custom .bb Files</title>
|
|
|
|
<para>
|
|
One way to get additional software into an image is to create a custom image.
|
|
The following example shows the form for the two lines you need:
|
|
<literallayout class='monospaced'>
|
|
IMAGE_INSTALL = "packagegroup-core-x11-base package1 package2"
|
|
|
|
inherit core-image
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
By creating a custom image, a developer has total control
|
|
over the contents of the image.
|
|
It is important to use the correct names of packages in the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'>IMAGE_INSTALL</ulink></filename>
|
|
variable.
|
|
You must use the OpenEmbedded notation and not the Debian notation for the names
|
|
(e.g. <filename>eglibc-dev</filename> instead of <filename>libc6-dev</filename>).
|
|
</para>
|
|
|
|
<para>
|
|
The other method for creating a custom image is to base it on an existing image.
|
|
For example, if you want to create an image based on <filename>core-image-sato</filename>
|
|
but add the additional package <filename>strace</filename> to the image,
|
|
copy the <filename>meta/recipes-sato/images/core-image-sato.bb</filename> to a
|
|
new <filename>.bb</filename> and add the following line to the end of the copy:
|
|
<literallayout class='monospaced'>
|
|
IMAGE_INSTALL += "strace"
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-customimage-customtasks'>
|
|
<title>Customizing Images Using Custom Package Groups</title>
|
|
|
|
<para>
|
|
For complex custom images, the best approach is to create a custom package group recipe
|
|
that is used to build the image or images.
|
|
A good example of a package group recipe is
|
|
<filename>meta/recipes-core/packagegroups/packagegroup-core-boot.bb</filename>.
|
|
The
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES'>PACKAGES</ulink></filename>
|
|
variable lists the package group packages you wish to produce. <filename>inherit packagegroup</filename>
|
|
sets appropriate default values and automatically adds <filename>-dev</filename>
|
|
and <filename>-dbg</filename> complementary
|
|
packages for every package specified in <filename>PACKAGES</filename>.
|
|
Note that the inherit line should be towards
|
|
the top of the recipe, certainly before you set <filename>PACKAGES</filename>.
|
|
For each package you specify in <filename>PACKAGES</filename>, you can use
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-RDEPENDS'>RDEPENDS</ulink></filename>
|
|
and
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-RRECOMMENDS'>RRECOMMENDS</ulink></filename>
|
|
entries to provide a list of packages the parent task package should contain.
|
|
Following is an example:
|
|
<literallayout class='monospaced'>
|
|
DESCRIPTION = "My Custom Package Groups"
|
|
|
|
inherit packagegroup
|
|
|
|
PACKAGES = "\
|
|
packagegroup-custom-apps \
|
|
packagegroup-custom-tools \
|
|
"
|
|
|
|
RDEPENDS_packagegroup-custom-apps = "\
|
|
dropbear \
|
|
portmap \
|
|
psplash"
|
|
|
|
RDEPENDS_packagegroup-custom-tools = "\
|
|
oprofile \
|
|
oprofileui-server \
|
|
lttng-control \
|
|
lttng-viewer"
|
|
|
|
RRECOMMENDS_packagegroup-custom-tools = "\
|
|
kernel-module-oprofile"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
In the previous example, two package group packages are created with their dependencies and their
|
|
recommended package dependencies listed: <filename>packagegroup-custom-apps</filename>, and
|
|
<filename>packagegroup-custom-tools</filename>.
|
|
To build an image using these package group packages, you need to add
|
|
<filename>packagegroup-custom-apps</filename> and/or
|
|
<filename>packagegroup-custom-tools</filename> to
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'>IMAGE_INSTALL</ulink></filename>.
|
|
For other forms of image dependencies see the other areas of this section.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-customimage-imagefeatures'>
|
|
<title>Customizing Images Using Custom <filename>IMAGE_FEATURES</filename> and
|
|
<filename>EXTRA_IMAGE_FEATURES</filename></title>
|
|
|
|
<para>
|
|
You might want to customize your image by enabling or
|
|
disabling high-level image features by using the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGE_FEATURES'><filename>EXTRA_IMAGE_FEATURES</filename></ulink>
|
|
variables.
|
|
Although the functions for both variables are nearly equivalent,
|
|
best practices dictate using <filename>IMAGE_FEATURES</filename>
|
|
from within a recipe and using
|
|
<filename>EXTRA_IMAGE_FEATURES</filename> from within
|
|
your <filename>local.conf</filename> file, which is found in the
|
|
<link linkend='build-directory'>Build Directory</link>.
|
|
</para>
|
|
|
|
<para>
|
|
To understand how these features work, the best reference is
|
|
<filename>meta/classes/core-image.bbclass</filename>.
|
|
In summary, the file looks at the contents of the
|
|
<filename>IMAGE_FEATURES</filename> variable and then maps
|
|
those contents into a set of package groups.
|
|
Based on this information, the build system automatically
|
|
adds the appropriate packages to the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'><filename>IMAGE_INSTALL</filename></ulink>
|
|
variable.
|
|
Effectively, you are enabling extra features by extending the
|
|
class or creating a custom class for use with specialized image
|
|
<filename>.bb</filename> files.
|
|
</para>
|
|
|
|
<para>
|
|
Use the <filename>EXTRA_IMAGE_FEATURES</filename> variable
|
|
from within your local configuration file.
|
|
Using a separate area from which to enable features with
|
|
this variable helps you avoid overwriting the features in the
|
|
image recipe that are enabled with
|
|
<filename>IMAGE_FEATURES</filename>.
|
|
The value of <filename>EXTRA_IMAGE_FEATURES</filename> is added
|
|
to <filename>IMAGE_FEATURES</filename> within
|
|
<filename>meta/conf/bitbake.conf</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
To illustrate how you can use these variables to modify your
|
|
image, consider an example that selects the SSH server.
|
|
The Yocto Project ships with two SSH servers you can use
|
|
with your images: Dropbear and OpenSSH.
|
|
Dropbear is a minimal SSH server appropriate for
|
|
resource-constrained environments, while OpenSSH is a
|
|
well-known standard SSH server implementation.
|
|
By default, the <filename>core-image-sato</filename> image
|
|
is configured to use Dropbear.
|
|
The <filename>core-image-basic</filename> and
|
|
<filename>core-image-lsb</filename> images both
|
|
include OpenSSH.
|
|
The <filename>core-image-minimal</filename> image does not
|
|
contain an SSH server.
|
|
</para>
|
|
|
|
<para>
|
|
You can customize your image and change these defaults.
|
|
Edit the <filename>IMAGE_FEATURES</filename> variable
|
|
in your recipe or use the
|
|
<filename>EXTRA_IMAGE_FEATURES</filename> in your
|
|
<filename>local.conf</filename> file so that it configures the
|
|
image you are working with to include
|
|
<filename>ssh-server-dropbear</filename> or
|
|
<filename>ssh-server-openssh</filename>.
|
|
</para>
|
|
|
|
<note>
|
|
See the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Images</ulink>"
|
|
section in the Yocto Project Reference Manual for a complete
|
|
list of image features that ship with the Yocto Project.
|
|
</note>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-customimage-localconf'>
|
|
<title>Customizing Images Using <filename>local.conf</filename></title>
|
|
|
|
<para>
|
|
It is possible to customize image contents by using variables from your
|
|
local configuration in your <filename>conf/local.conf</filename> file.
|
|
Because it is limited to local use, this method generally only allows you to
|
|
add packages and is not as flexible as creating your own customized image.
|
|
When you add packages using local variables this way, you need to realize that
|
|
these variable changes affect all images at the same time and might not be
|
|
what you require.
|
|
</para>
|
|
|
|
<para>
|
|
The simplest way to add extra packages to all images is by using the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'>IMAGE_INSTALL</ulink></filename>
|
|
variable with the <filename>_append</filename> operator:
|
|
<literallayout class='monospaced'>
|
|
IMAGE_INSTALL_append = " strace"
|
|
</literallayout>
|
|
Use of the syntax is important.
|
|
Specifically, the space between the quote and the package name, which is
|
|
<filename>strace</filename> in this example.
|
|
This space is required since the <filename>_append</filename>
|
|
operator does not add the space.
|
|
</para>
|
|
|
|
<para>
|
|
Furthermore, you must use <filename>_append</filename> instead of the <filename>+=</filename>
|
|
operator if you want to avoid ordering issues.
|
|
The reason for this is because doing so unconditionally appends to the variable and
|
|
avoids ordering problems due to the variable being set in image recipes and
|
|
<filename>.bbclass</filename> files with operators like <filename>?=</filename>.
|
|
Using <filename>_append</filename> ensures the operation takes affect.
|
|
</para>
|
|
|
|
<para>
|
|
As shown in its simplest use, <filename>IMAGE_INSTALL_append</filename> affects
|
|
all images.
|
|
It is possible to extend the syntax so that the variable applies to a specific image only.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
IMAGE_INSTALL_append_pn-core-image-minimal = " strace"
|
|
</literallayout>
|
|
This example adds <filename>strace</filename> to <filename>core-image-minimal</filename>
|
|
only.
|
|
</para>
|
|
|
|
<para>
|
|
You can add packages using a similar approach through the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-CORE_IMAGE_EXTRA_INSTALL'>CORE_IMAGE_EXTRA_INSTALL</ulink></filename>
|
|
variable.
|
|
If you use this variable, only <filename>core-image-*</filename> images are affected.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-addpkg'>
|
|
<title>Writing a Recipe to Add a Package to Your Image</title>
|
|
|
|
<para>
|
|
Recipes add packages to your image.
|
|
Writing a recipe means creating a <filename>.bb</filename> file that sets some
|
|
variables.
|
|
For information on variables that are useful for recipes and for information about recipe naming
|
|
issues, see the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#ref-varlocality-recipe-required'>Required</ulink>"
|
|
section of the Yocto Project Reference Manual.
|
|
</para>
|
|
|
|
<para>
|
|
Before writing a recipe from scratch, it is often useful to check
|
|
whether someone else has written one already.
|
|
OpenEmbedded is a good place to look as it has a wider scope and range of packages.
|
|
Because the Yocto Project aims to be compatible with OpenEmbedded, most recipes
|
|
you find there should work for you.
|
|
</para>
|
|
|
|
<para>
|
|
For new packages, the simplest way to add a recipe is to base it on a similar
|
|
pre-existing recipe.
|
|
The sections that follow provide some examples that show how to add standard
|
|
types of packages.
|
|
</para>
|
|
|
|
<note>
|
|
<para>When writing shell functions, you need to be aware of BitBake's
|
|
curly brace parsing.
|
|
If a recipe uses a closing curly brace within the function and
|
|
the character has no leading spaces, BitBake produces a parsing
|
|
error.
|
|
If you use a pair of curly brace in a shell function, the
|
|
closing curly brace must not be located at the start of the line
|
|
without leading spaces.</para>
|
|
<para>Here is an example that causes BitBake to produce a parsing
|
|
error:
|
|
<literallayout class='monospaced'>
|
|
fakeroot create_shar() {
|
|
cat << "EOF" > ${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.sh
|
|
usage()
|
|
{
|
|
echo "test"
|
|
###### The following "}" at the start of the line causes a parsing error ######
|
|
}
|
|
EOF
|
|
}
|
|
</literallayout>
|
|
Writing the recipe this way avoids the error:
|
|
<literallayout class='monospaced'>
|
|
fakeroot create_shar() {
|
|
cat << "EOF" > ${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.sh
|
|
usage()
|
|
{
|
|
echo "test"
|
|
######The following "}" with a leading space at the start of the line avoids the error ######
|
|
}
|
|
EOF
|
|
}
|
|
</literallayout></para>
|
|
</note>
|
|
|
|
<section id='usingpoky-extend-addpkg-singlec'>
|
|
<title>Single .c File Package (Hello World!)</title>
|
|
|
|
<para>
|
|
Building an application from a single file that is stored locally (e.g. under
|
|
<filename>files/</filename>) requires a recipe that has the file listed in
|
|
the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'>SRC_URI</ulink></filename>
|
|
variable.
|
|
Additionally, you need to manually write the <filename>do_compile</filename> and
|
|
<filename>do_install</filename> tasks.
|
|
The <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-S'>S</ulink></filename>
|
|
variable defines the
|
|
directory containing the source code, which is set to
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-WORKDIR'>
|
|
WORKDIR</ulink></filename> in this case - the directory BitBake uses for the build.
|
|
<literallayout class='monospaced'>
|
|
DESCRIPTION = "Simple helloworld application"
|
|
SECTION = "examples"
|
|
LICENSE = "MIT"
|
|
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
|
|
PR = "r0"
|
|
|
|
SRC_URI = "file://helloworld.c"
|
|
|
|
S = "${WORKDIR}"
|
|
|
|
do_compile() {
|
|
${CC} helloworld.c -o helloworld
|
|
}
|
|
|
|
do_install() {
|
|
install -d ${D}${bindir}
|
|
install -m 0755 helloworld ${D}${bindir}
|
|
}
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
By default, the <filename>helloworld</filename>, <filename>helloworld-dbg</filename>,
|
|
and <filename>helloworld-dev</filename> packages are built.
|
|
For information on how to customize the packaging process, see the
|
|
"<link linkend='splitting-an-application-into-multiple-packages'>Splitting an Application
|
|
into Multiple Packages</link>" section.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-addpkg-autotools'>
|
|
<title>Autotooled Package</title>
|
|
<para>
|
|
Applications that use Autotools such as <filename>autoconf</filename> and
|
|
<filename>automake</filename> require a recipe that has a source archive listed in
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'>SRC_URI</ulink></filename> and
|
|
also inherits Autotools, which instructs BitBake to use the
|
|
<filename>autotools.bbclass</filename> file, which contains the definitions of all the steps
|
|
needed to build an Autotool-based application.
|
|
The result of the build is automatically packaged.
|
|
And, if the application uses NLS for localization, packages with local information are
|
|
generated (one package per language).
|
|
Following is one example: (<filename>hello_2.3.bb</filename>)
|
|
<literallayout class='monospaced'>
|
|
DESCRIPTION = "GNU Helloworld application"
|
|
SECTION = "examples"
|
|
LICENSE = "GPLv2+"
|
|
LIC_FILES_CHKSUM = "file://COPYING;md5=751419260aa954499f7abaabaa882bbe"
|
|
PR = "r0"
|
|
|
|
SRC_URI = "${GNU_MIRROR}/hello/hello-${PV}.tar.gz"
|
|
|
|
inherit autotools gettext
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
The variable
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</ulink></filename>
|
|
is used to track source license changes as described in the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#usingpoky-configuring-LIC_FILES_CHKSUM'>Tracking License Changes</ulink>" section.
|
|
You can quickly create Autotool-based recipes in a manner similar to the previous example.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-addpkg-makefile'>
|
|
<title>Makefile-Based Package</title>
|
|
|
|
<para>
|
|
Applications that use GNU <filename>make</filename> also require a recipe that has
|
|
the source archive listed in
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'>SRC_URI</ulink></filename>.
|
|
You do not need to add a <filename>do_compile</filename> step since by default BitBake
|
|
starts the <filename>make</filename> command to compile the application.
|
|
If you need additional <filename>make</filename> options, you should store them in the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_OEMAKE'>EXTRA_OEMAKE</ulink></filename>
|
|
variable.
|
|
BitBake passes these options into the <filename>make</filename> GNU invocation.
|
|
Note that a <filename>do_install</filename> task is still required.
|
|
Otherwise, BitBake runs an empty <filename>do_install</filename> task by default.
|
|
</para>
|
|
|
|
<para>
|
|
Some applications might require extra parameters to be passed to the compiler.
|
|
For example, the application might need an additional header path.
|
|
You can accomplish this by adding to the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-CFLAGS'>CFLAGS</ulink></filename> variable.
|
|
The following example shows this:
|
|
<literallayout class='monospaced'>
|
|
CFLAGS_prepend = "-I ${S}/include "
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
In the following example, <filename>mtd-utils</filename> is a makefile-based package:
|
|
<literallayout class='monospaced'>
|
|
DESCRIPTION = "Tools for managing memory technology devices."
|
|
SECTION = "base"
|
|
DEPENDS = "zlib lzo e2fsprogs util-linux"
|
|
HOMEPAGE = "http://www.linux-mtd.infradead.org/"
|
|
LICENSE = "GPLv2+"
|
|
LIC_FILES_CHKSUM = "file://COPYING;md5=0636e73ff0215e8d672dc4c32c317bb3 \
|
|
file://include/common.h;beginline=1;endline=17;md5=ba05b07912a44ea2bf81ce409380049c"
|
|
|
|
SRC_URI = "git://git.infradead.org/mtd-utils.git;protocol=git;tag=995cfe51b0a3cf32f381c140bf72b21bf91cef1b \
|
|
file://add-exclusion-to-mkfs-jffs2-git-2.patch"
|
|
|
|
S = "${WORKDIR}/git/"
|
|
|
|
PR = "r1"
|
|
|
|
EXTRA_OEMAKE = "'CC=${CC}' 'RANLIB=${RANLIB}' 'AR=${AR}' \
|
|
'CFLAGS=${CFLAGS} -I${S}/include -DWITHOUT_XATTR' 'BUILDDIR=${S}'"
|
|
|
|
do_install () {
|
|
oe_runmake install DESTDIR=${D} SBINDIR=${sbindir} MANDIR=${mandir} \
|
|
INCLUDEDIR=${includedir}
|
|
install -d ${D}${includedir}/mtd/
|
|
for f in ${S}/include/mtd/*.h; do
|
|
install -m 0644 $f ${D}${includedir}/mtd/
|
|
done
|
|
}
|
|
|
|
PARALLEL_MAKE = ""
|
|
|
|
BBCLASSEXTEND = "native"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
If your sources are available as a tarball instead of a Git repository, you
|
|
will need to provide the URL to the tarball as well as an
|
|
<filename>md5</filename> or <filename>sha256</filename> sum of
|
|
the download.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
SRC_URI="ftp://ftp.infradead.org/pub/mtd-utils/mtd-utils-1.4.9.tar.bz2"
|
|
SRC_URI[md5sum]="82b8e714b90674896570968f70ca778b"
|
|
</literallayout>
|
|
You can generate the <filename>md5</filename> or <filename>sha256</filename> sums
|
|
by using the <filename>md5sum</filename> or <filename>sha256sum</filename> commands
|
|
with the target file as the only argument.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
$ md5sum mtd-utils-1.4.9.tar.bz2
|
|
82b8e714b90674896570968f70ca778b mtd-utils-1.4.9.tar.bz2
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='splitting-an-application-into-multiple-packages'>
|
|
<title>Splitting an Application into Multiple Packages</title>
|
|
|
|
<para>
|
|
You can use the variables
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES'>PACKAGES</ulink></filename> and
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-FILES'>FILES</ulink></filename>
|
|
to split an application into multiple packages.
|
|
</para>
|
|
|
|
<para>
|
|
Following is an example that uses the <filename>libXpm</filename> recipe.
|
|
By default, this recipe generates a single package that contains the library along
|
|
with a few binaries.
|
|
You can modify the recipe to split the binaries into separate packages:
|
|
<literallayout class='monospaced'>
|
|
require xorg-lib-common.inc
|
|
|
|
DESCRIPTION = "X11 Pixmap library"
|
|
LICENSE = "X-BSD"
|
|
LIC_FILES_CHKSUM = "file://COPYING;md5=3e07763d16963c3af12db271a31abaa5"
|
|
DEPENDS += "libxext libsm libxt"
|
|
PR = "r3"
|
|
PE = "1"
|
|
|
|
XORG_PN = "libXpm"
|
|
|
|
PACKAGES =+ "sxpm cxpm"
|
|
FILES_cxpm = "${bindir}/cxpm"
|
|
FILES_sxpm = "${bindir}/sxpm"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
In the previous example, we want to ship the <filename>sxpm</filename>
|
|
and <filename>cxpm</filename> binaries in separate packages.
|
|
Since <filename>bindir</filename> would be packaged into the main
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PN'>PN</ulink></filename>
|
|
package by default, we prepend the <filename>PACKAGES</filename>
|
|
variable so additional package names are added to the start of list.
|
|
This results in the extra <filename>FILES_*</filename>
|
|
variables then containing information that define which files and
|
|
directories go into which packages.
|
|
Files included by earlier packages are skipped by latter packages.
|
|
Thus, the main <filename>PN</filename> package
|
|
does not include the above listed files.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='usingpoky-extend-addpkg-postinstalls'>
|
|
<title>Post-Installation Scripts</title>
|
|
|
|
<para>
|
|
To add a post-installation script to a package, add a
|
|
<filename>pkg_postinst_PACKAGENAME()</filename> function to the
|
|
<filename>.bb</filename> file and use
|
|
<filename>PACKAGENAME</filename> as the name of the package you want to attach to the
|
|
<filename>postinst</filename> script.
|
|
Normally,
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PN'>PN</ulink></filename>
|
|
can be used, which automatically expands to <filename>PACKAGENAME</filename>.
|
|
A post-installation function has the following structure:
|
|
<literallayout class='monospaced'>
|
|
pkg_postinst_PACKAGENAME () {
|
|
#!/bin/sh -e
|
|
# Commands to carry out
|
|
}
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
The script defined in the post-installation function is called when the
|
|
root filesystem is created.
|
|
If the script succeeds, the package is marked as installed.
|
|
If the script fails, the package is marked as unpacked and the script is
|
|
executed when the image boots again.
|
|
</para>
|
|
|
|
<para>
|
|
Sometimes it is necessary for the execution of a post-installation
|
|
script to be delayed until the first boot.
|
|
For example, the script might need to be executed on the device itself.
|
|
To delay script execution until boot time, use the following structure in the
|
|
post-installation script:
|
|
<literallayout class='monospaced'>
|
|
pkg_postinst_PACKAGENAME () {
|
|
#!/bin/sh -e
|
|
if [ x"$D" = "x" ]; then
|
|
# Actions to carry out on the device go here
|
|
else
|
|
exit 1
|
|
fi
|
|
}
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
The previous example delays execution until the image boots again because the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-D'>D</ulink></filename>
|
|
variable points
|
|
to the directory containing the image when the root filesystem is created at build time but
|
|
is unset when executed on the first boot.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="platdev-newmachine">
|
|
<title>Adding a New Machine</title>
|
|
|
|
<para>
|
|
Adding a new machine to the Yocto Project is a straightforward process.
|
|
This section provides information that gives you an idea of the changes you must make.
|
|
The information covers adding machines similar to those the Yocto Project already supports.
|
|
Although well within the capabilities of the Yocto Project, adding a totally new architecture
|
|
might require
|
|
changes to <filename>gcc/eglibc</filename> and to the site information, which is
|
|
beyond the scope of this manual.
|
|
</para>
|
|
|
|
<para>
|
|
For a complete example that shows how to add a new machine,
|
|
see the
|
|
"<ulink url='&YOCTO_DOCS_BSP_URL;#creating-a-new-bsp-layer-using-the-yocto-bsp-script'>Creating a New BSP Layer Using the yocto-bsp Script</ulink>"
|
|
in the Yocto Project Board Support Package (BSP) Developer's Guide.
|
|
</para>
|
|
|
|
<section id="platdev-newmachine-conffile">
|
|
<title>Adding the Machine Configuration File</title>
|
|
|
|
<para>
|
|
To add a machine configuration, you need to add a <filename>.conf</filename> file
|
|
with details of the device being added to the <filename>conf/machine/</filename> file.
|
|
The name of the file determines the name the OpenEmbedded build system
|
|
uses to reference the new machine.
|
|
</para>
|
|
|
|
<para>
|
|
The most important variables to set in this file are as follows:
|
|
<itemizedlist>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-TARGET_ARCH'>TARGET_ARCH</ulink></filename>
|
|
(e.g. "arm")</para></listitem>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'>PREFERRED_PROVIDER</ulink>_virtual/kernel</filename>
|
|
(see below)</para></listitem>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE_FEATURES'>MACHINE_FEATURES</ulink></filename>
|
|
(e.g. "apm screen wifi")</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
You might also need these variables:
|
|
<itemizedlist>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SERIAL_CONSOLES'>SERIAL_CONSOLES</ulink></filename>
|
|
(e.g. "115200 ttyS0")</para></listitem>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-KERNEL_IMAGETYPE'>KERNEL_IMAGETYPE</ulink></filename>
|
|
(e.g. "zImage")</para></listitem>
|
|
<listitem><para><filename><ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FSTYPES'>IMAGE_FSTYPES</ulink></filename>
|
|
(e.g. "tar.gz jffs2")</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
You can find full details on these variables in the reference section.
|
|
You can leverage many existing machine <filename>.conf</filename> files from
|
|
<filename>meta/conf/machine/</filename>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-newmachine-kernel">
|
|
<title>Adding a Kernel for the Machine</title>
|
|
|
|
<para>
|
|
The OpenEmbedded build system needs to be able to build a kernel for the machine.
|
|
You need to either create a new kernel recipe for this machine, or extend an
|
|
existing recipe.
|
|
You can find several kernel examples in the
|
|
Source Directory at <filename>meta/recipes-kernel/linux</filename>
|
|
that you can use as references.
|
|
</para>
|
|
|
|
<para>
|
|
If you are creating a new recipe, normal recipe-writing rules apply for setting
|
|
up a
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'>SRC_URI</ulink></filename>.
|
|
Thus, you need to specify any necessary patches and set
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-S'>S</ulink></filename> to point at the source code.
|
|
You need to create a <filename>configure</filename> task that configures the
|
|
unpacked kernel with a defconfig.
|
|
You can do this by using a <filename>make defconfig</filename> command or,
|
|
more commonly, by copying in a suitable <filename>defconfig</filename> file and and then running
|
|
<filename>make oldconfig</filename>.
|
|
By making use of <filename>inherit kernel</filename> and potentially some of the
|
|
<filename>linux-*.inc</filename> files, most other functionality is
|
|
centralized and the the defaults of the class normally work well.
|
|
</para>
|
|
|
|
<para>
|
|
If you are extending an existing kernel, it is usually a matter of adding a
|
|
suitable defconfig file.
|
|
The file needs to be added into a location similar to defconfig files
|
|
used for other machines in a given kernel.
|
|
A possible way to do this is by listing the file in the
|
|
<filename>SRC_URI</filename> and adding the machine to the expression in
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-COMPATIBLE_MACHINE'>COMPATIBLE_MACHINE</ulink></filename>:
|
|
<literallayout class='monospaced'>
|
|
COMPATIBLE_MACHINE = '(qemux86|qemumips)'
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-newmachine-formfactor">
|
|
<title>Adding a Formfactor Configuration File</title>
|
|
|
|
<para>
|
|
A formfactor configuration file provides information about the
|
|
target hardware for which the image is being built and information that
|
|
the build system cannot obtain from other sources such as the kernel.
|
|
Some examples of information contained in a formfactor configuration file include
|
|
framebuffer orientation, whether or not the system has a keyboard,
|
|
the positioning of the keyboard in relation to the screen, and
|
|
the screen resolution.
|
|
</para>
|
|
|
|
<para>
|
|
The build system uses reasonable defaults in most cases.
|
|
However, if customization is
|
|
necessary, you need to create a <filename>machconfig</filename> file
|
|
in the <filename>meta/recipes-bsp/formfactor/files</filename>
|
|
directory.
|
|
This directory contains directories for specific machines such as
|
|
<filename>qemuarm</filename> and <filename>qemux86</filename>.
|
|
For information about the settings available and the defaults, see the
|
|
<filename>meta/recipes-bsp/formfactor/files/config</filename> file found in the
|
|
same area.
|
|
</para>
|
|
|
|
<para>
|
|
Following is an example for qemuarm:
|
|
<literallayout class='monospaced'>
|
|
HAVE_TOUCHSCREEN=1
|
|
HAVE_KEYBOARD=1
|
|
|
|
DISPLAY_CAN_ROTATE=0
|
|
DISPLAY_ORIENTATION=0
|
|
#DISPLAY_WIDTH_PIXELS=640
|
|
#DISPLAY_HEIGHT_PIXELS=480
|
|
#DISPLAY_BPP=16
|
|
DISPLAY_DPI=150
|
|
DISPLAY_SUBPIXEL_ORDER=vrgb
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="platdev-working-with-libraries">
|
|
<title>Working With Libraries</title>
|
|
|
|
<para>
|
|
Libraries are an integral part of your system.
|
|
This section describes some common practices you might find
|
|
helpful when working with libraries to build your system:
|
|
<itemizedlist>
|
|
<listitem><para><link linkend='including-static-library-files'>How to include static library files</link>
|
|
</para></listitem>
|
|
<listitem><para><link linkend='combining-multiple-versions-library-files-into-one-image'>How to use the Multilib feature to combine multiple versions of library files into a single image</link>
|
|
</para></listitem>
|
|
<listitem><para><link linkend='installing-multiple-versions-of-the-same-library'>How to install multiple versions of the same library in parallel on the same system</link>
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<section id='including-static-library-files'>
|
|
<title>Including Static Library Files</title>
|
|
|
|
<para>
|
|
If you are building a library and the library offers static linking, you can control
|
|
which static library files (<filename>*.a</filename> files) get included in the
|
|
built library.
|
|
</para>
|
|
|
|
<para>
|
|
The <ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES'><filename>PACKAGES</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-FILES'><filename>FILES_*</filename></ulink>
|
|
variables in the
|
|
<filename>meta/conf/bitbake.conf</filename> configuration file define how files installed
|
|
by the <filename>do_install</filename> task are packaged.
|
|
By default, the <filename>PACKAGES</filename> variable contains
|
|
<filename>${PN}-staticdev</filename>, which includes all static library files.
|
|
<note>
|
|
Some previously released versions of the Yocto Project
|
|
defined the static library files through
|
|
<filename>${PN}-dev</filename>.
|
|
</note>
|
|
Following, is part of the BitBake configuration file.
|
|
You can see where the static library files are defined:
|
|
<literallayout class='monospaced'>
|
|
PACKAGES = "${PN}-dbg ${PN} ${PN}-doc ${PN}-dev ${PN}-staticdev ${PN}-locale"
|
|
PACKAGES_DYNAMIC = "${PN}-locale-*"
|
|
FILES = ""
|
|
|
|
FILES_${PN} = "${bindir}/* ${sbindir}/* ${libexecdir}/* ${libdir}/lib*${SOLIBS} \
|
|
${sysconfdir} ${sharedstatedir} ${localstatedir} \
|
|
${base_bindir}/* ${base_sbindir}/* \
|
|
${base_libdir}/*${SOLIBS} \
|
|
${datadir}/${BPN} ${libdir}/${BPN}/* \
|
|
${datadir}/pixmaps ${datadir}/applications \
|
|
${datadir}/idl ${datadir}/omf ${datadir}/sounds \
|
|
${libdir}/bonobo/servers"
|
|
|
|
FILES_${PN}-doc = "${docdir} ${mandir} ${infodir} ${datadir}/gtk-doc \
|
|
${datadir}/gnome/help"
|
|
SECTION_${PN}-doc = "doc"
|
|
|
|
FILES_${PN}-dev = "${includedir} ${libdir}/lib*${SOLIBSDEV} ${libdir}/*.la \
|
|
${libdir}/*.o ${libdir}/pkgconfig ${datadir}/pkgconfig \
|
|
${datadir}/aclocal ${base_libdir}/*.o"
|
|
SECTION_${PN}-dev = "devel"
|
|
ALLOW_EMPTY_${PN}-dev = "1"
|
|
RDEPENDS_${PN}-dev = "${PN} (= ${EXTENDPKGV})"
|
|
|
|
FILES_${PN}-staticdev = "${libdir}/*.a ${base_libdir}/*.a"
|
|
SECTION_${PN}-staticdev = "devel"
|
|
RDEPENDS_${PN}-staticdev = "${PN}-dev (= ${EXTENDPKGV})"
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="combining-multiple-versions-library-files-into-one-image">
|
|
<title>Combining Multiple Versions of Library Files into One Image</title>
|
|
|
|
<para>
|
|
The build system offers the ability to build libraries with different
|
|
target optimizations or architecture formats and combine these together
|
|
into one system image.
|
|
You can link different binaries in the image
|
|
against the different libraries as needed for specific use cases.
|
|
This feature is called "Multilib."
|
|
</para>
|
|
|
|
<para>
|
|
An example would be where you have most of a system compiled in 32-bit
|
|
mode using 32-bit libraries, but you have something large, like a database
|
|
engine, that needs to be a 64-bit application and uses 64-bit libraries.
|
|
Multilib allows you to get the best of both 32-bit and 64-bit libraries.
|
|
</para>
|
|
|
|
<para>
|
|
While the Multilib feature is most commonly used for 32 and 64-bit differences,
|
|
the approach the build system uses facilitates different target optimizations.
|
|
You could compile some binaries to use one set of libraries and other binaries
|
|
to use other different sets of libraries.
|
|
The libraries could differ in architecture, compiler options, or other
|
|
optimizations.
|
|
</para>
|
|
|
|
<para>
|
|
This section overviews the Multilib process only.
|
|
For more details on how to implement Multilib, see the
|
|
<ulink url='&YOCTO_WIKI_URL;/wiki/Multilib'>Multilib</ulink> wiki
|
|
page.
|
|
</para>
|
|
|
|
<para>
|
|
Aside from this wiki page, several examples exist in the
|
|
<ulink url='&YOCTO_GIT_URL;/cgit.cgi/poky/tree/meta-skeleton'><filename>meta-skeleton</filename></ulink>
|
|
layer found in the
|
|
<link linkend='source-directory'>Source Directory</link>:
|
|
<itemizedlist>
|
|
<listitem><para><filename>conf/multilib-example.conf</filename>
|
|
configuration file</para></listitem>
|
|
<listitem><para><filename>conf/multilib-example2.conf</filename>
|
|
configuration file</para></listitem>
|
|
<listitem><para><filename>recipes-multilib/images/core-image-multilib-example.bb</filename>
|
|
recipe</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<section id='preparing-to-use-multilib'>
|
|
<title>Preparing to Use Multilib</title>
|
|
|
|
<para>
|
|
User-specific requirements drive the Multilib feature.
|
|
Consequently, there is no one "out-of-the-box" configuration that likely
|
|
exists to meet your needs.
|
|
</para>
|
|
|
|
<para>
|
|
In order to enable Multilib, you first need to ensure your recipe is
|
|
extended to support multiple libraries.
|
|
Many standard recipes are already extended and support multiple libraries.
|
|
You can check in the <filename>meta/conf/multilib.conf</filename>
|
|
configuration file in the
|
|
<link linkend='source-directory'>Source Directory</link> to see how this is
|
|
done using the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBCLASSEXTEND'><filename>BBCLASSEXTEND</filename></ulink>
|
|
variable.
|
|
Eventually, all recipes will be covered and this list will be unneeded.
|
|
</para>
|
|
|
|
<para>
|
|
For the most part, the Multilib class extension works automatically to
|
|
extend the package name from <filename>${PN}</filename> to
|
|
<filename>${MLPREFIX}${PN}</filename>, where <filename>MLPREFIX</filename>
|
|
is the particular multilib (e.g. "lib32-" or "lib64-").
|
|
Standard variables such as
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DEPENDS'><filename>DEPENDS</filename></ulink>,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-RDEPENDS'><filename>RDEPENDS</filename></ulink>,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-RPROVIDES'><filename>RPROVIDES</filename></ulink>,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-RRECOMMENDS'><filename>RRECOMMENDS</filename></ulink>,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES'><filename>PACKAGES</filename></ulink>,
|
|
and <filename>PACKAGES_DYNAMIC</filename> are automatically extended by the system.
|
|
If you are extending any manual code in the recipe, you can use the
|
|
<filename>${MLPREFIX}</filename> variable to ensure those names are extended
|
|
correctly.
|
|
This automatic extension code resides in <filename>multilib.bbclass</filename>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='using-multilib'>
|
|
<title>Using Multilib</title>
|
|
|
|
<para>
|
|
After you have set up the recipes, you need to define the actual
|
|
combination of multiple libraries you want to build.
|
|
You accomplish this through your <filename>local.conf</filename>
|
|
configuration file in the
|
|
<link linkend='build-directory'>Build Directory</link>.
|
|
An example configuration would be as follows:
|
|
<literallayout class='monospaced'>
|
|
MACHINE = "qemux86-64"
|
|
require conf/multilib.conf
|
|
MULTILIBS = "multilib:lib32"
|
|
DEFAULTTUNE_virtclass-multilib-lib32 = "x86"
|
|
IMAGE_INSTALL = "lib32-connman"
|
|
</literallayout>
|
|
This example enables an
|
|
additional library named <filename>lib32</filename> alongside the
|
|
normal target packages.
|
|
When combining these "lib32" alternatives, the example uses "x86" for tuning.
|
|
For information on this particular tuning, see
|
|
<filename>meta/conf/machine/include/ia32/arch-ia32.inc</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
The example then includes <filename>lib32-connman</filename>
|
|
in all the images, which illustrates one method of including a
|
|
multiple library dependency.
|
|
You can use a normal image build to include this dependency,
|
|
for example:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake core-image-sato
|
|
</literallayout>
|
|
You can also build Multilib packages specifically with a command like this:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake lib32-connman
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='additional-implementation-details'>
|
|
<title>Additional Implementation Details</title>
|
|
|
|
<para>
|
|
Different packaging systems have different levels of native Multilib
|
|
support.
|
|
For the RPM Package Management System, the following implementation details
|
|
exist:
|
|
<itemizedlist>
|
|
<listitem><para>A unique architecture is defined for the Multilib packages,
|
|
along with creating a unique deploy folder under
|
|
<filename>tmp/deploy/rpm</filename> in the
|
|
<link linkend='build-directory'>Build Directory</link>.
|
|
For example, consider <filename>lib32</filename> in a
|
|
<filename>qemux86-64</filename> image.
|
|
The possible architectures in the system are "all", "qemux86_64",
|
|
"lib32_qemux86_64", and "lib32_x86".</para></listitem>
|
|
<listitem><para>The <filename>${MLPREFIX}</filename> variable is stripped from
|
|
<filename>${PN}</filename> during RPM packaging.
|
|
The naming for a normal RPM package and a Multilib RPM package in a
|
|
<filename>qemux86-64</filename> system resolves to something similar to
|
|
<filename>bash-4.1-r2.x86_64.rpm</filename> and
|
|
<filename>bash-4.1.r2.lib32_x86.rpm</filename>, respectively.
|
|
</para></listitem>
|
|
<listitem><para>When installing a Multilib image, the RPM backend first
|
|
installs the base image and then installs the Multilib libraries.
|
|
</para></listitem>
|
|
<listitem><para>The build system relies on RPM to resolve the identical files in the
|
|
two (or more) Multilib packages.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
For the IPK Package Management System, the following implementation details exist:
|
|
<itemizedlist>
|
|
<listitem><para>The <filename>${MLPREFIX}</filename> is not stripped from
|
|
<filename>${PN}</filename> during IPK packaging.
|
|
The naming for a normal RPM package and a Multilib IPK package in a
|
|
<filename>qemux86-64</filename> system resolves to something like
|
|
<filename>bash_4.1-r2.x86_64.ipk</filename> and
|
|
<filename>lib32-bash_4.1-rw_x86.ipk</filename>, respectively.
|
|
</para></listitem>
|
|
<listitem><para>The IPK deploy folder is not modified with
|
|
<filename>${MLPREFIX}</filename> because packages with and without
|
|
the Multilib feature can exist in the same folder due to the
|
|
<filename>${PN}</filename> differences.</para></listitem>
|
|
<listitem><para>IPK defines a sanity check for Multilib installation
|
|
using certain rules for file comparison, overridden, etc.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='installing-multiple-versions-of-the-same-library'>
|
|
<title>Installing Multiple Versions of the Same Library</title>
|
|
|
|
<para>
|
|
Situations can exist where you need to install and use
|
|
multiple versions of the same library on the same system
|
|
at the same time.
|
|
These situations almost always exist when a library API
|
|
changes and you have multiple pieces of software that
|
|
depend on the separate versions of the library.
|
|
To accommodate these situations, you can install multiple
|
|
versions of the same library in parallel on the same system.
|
|
</para>
|
|
|
|
<para>
|
|
The process is straight forward as long as the libraries use
|
|
proper versioning.
|
|
With properly versioned libraries, all you need to do to
|
|
individually specify the libraries is create separate,
|
|
appropriately named recipes where the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PN'><filename>PN</filename></ulink> part of the
|
|
name includes a portion that differentiates each library version
|
|
(e.g.the major part of the version number).
|
|
Thus, instead of having a single recipe that loads one version
|
|
of a library (e.g. <filename>clutter</filename>), you provide
|
|
multiple recipes that result in different versions
|
|
of the libraries you want.
|
|
As an example, the following two recipes would allow the
|
|
two separate versions of the <filename>clutter</filename>
|
|
library to co-exist on the same system:
|
|
<literallayout class='monospaced'>
|
|
clutter-1.6_1.6.20.bb
|
|
clutter-1.8_1.8.4.bb
|
|
</literallayout>
|
|
Additionally, if you have other recipes that depend on a given
|
|
library, you need to use the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DEPENDS'><filename>DEPENDS</filename></ulink>
|
|
variable to create the dependency.
|
|
Continuing with the same example, if you want to have a recipe
|
|
depend on the 1.8 version of the <filename>clutter</filename>
|
|
library, use the following in your recipe:
|
|
<literallayout class='monospaced'>
|
|
DEPENDS = "clutter-1.8"
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='configuring-the-kernel'>
|
|
<title>Configuring the Kernel</title>
|
|
|
|
<para>
|
|
Configuring the Yocto Project kernel consists of making sure the <filename>.config</filename>
|
|
file has all the right information in it for the image you are building.
|
|
You can use the <filename>menuconfig</filename> tool and configuration fragments to
|
|
make sure your <filename>.config</filename> file is just how you need it.
|
|
This section describes how to use <filename>menuconfig</filename>, create and use
|
|
configuration fragments, and how to interactively tweak your <filename>.config</filename>
|
|
file to create the leanest kernel configuration file possible.
|
|
</para>
|
|
|
|
<para>
|
|
For more information on kernel configuration, see the
|
|
"<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#changing-the-configuration'>Changing the Configuration</ulink>"
|
|
section in the Yocto Project Linux Kernel Development Manual.
|
|
</para>
|
|
|
|
<section id='using-menuconfig'>
|
|
<title>Using <filename>menuconfig</filename></title>
|
|
|
|
<para>
|
|
The easiest way to define kernel configurations is to set them through the
|
|
<filename>menuconfig</filename> tool.
|
|
This tool provides an interactive method with which
|
|
to set kernel configurations.
|
|
For general information on <filename>menuconfig</filename>, see
|
|
<ulink url='http://en.wikipedia.org/wiki/Menuconfig'></ulink>.
|
|
</para>
|
|
|
|
<para>
|
|
To use the <filename>menuconfig</filename> tool in the Yocto Project development
|
|
environment, you must build the tool using BitBake.
|
|
Thus, the environment must be set up using the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>&OE_INIT_FILE;</filename></ulink>
|
|
or
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#structure-memres-core-script'><filename>oe-init-build-env-memres</filename></ulink>
|
|
script found in the
|
|
<link linkend='build-directory'>Build Directory</link>.
|
|
The following commands build and invoke <filename>menuconfig</filename> assuming the
|
|
<link linkend='source-directory'>Source Directory</link>
|
|
top-level folder is <filename>~/poky</filename>:
|
|
<literallayout class='monospaced'>
|
|
$ cd ~/poky
|
|
$ source oe-init-build-env
|
|
$ bitbake linux-yocto -c menuconfig
|
|
</literallayout>
|
|
Once <filename>menuconfig</filename> comes up, its standard interface allows you to
|
|
interactively examine and configure all the kernel configuration parameters.
|
|
After making your changes, simply exit the tool and save your changes to
|
|
create an updated version of the <filename>.config</filename> configuration file.
|
|
</para>
|
|
|
|
<para>
|
|
Consider an example that configures the <filename>linux-yocto-3.4</filename>
|
|
kernel.
|
|
The OpenEmbedded build system recognizes this kernel as
|
|
<filename>linux-yocto</filename>.
|
|
Thus, the following commands from the shell in which you previously sourced the
|
|
environment initialization script cleans the shared state cache and the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-WORKDIR'><filename>WORKDIR</filename></ulink>
|
|
directory and then builds and launches <filename>menuconfig</filename>:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake linux-yocto -c menuconfig
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
Once <filename>menuconfig</filename> launches, use the interface
|
|
to navigate through the selections to find the configuration settings in
|
|
which you are interested.
|
|
For example, consider the <filename>CONFIG_SMP</filename> configuration setting.
|
|
You can find it at <filename>Processor Type and Features</filename> under
|
|
the configuration selection <filename>Symmetric Multi-processing Support</filename>.
|
|
After highlighting the selection, use the arrow keys to select or deselect
|
|
the setting.
|
|
When you are finished with all your selections, exit out and save them.
|
|
</para>
|
|
|
|
<para>
|
|
Saving the selections updates the <filename>.config</filename> configuration file.
|
|
This is the file that the OpenEmbedded build system uses to configure the
|
|
kernel during the build.
|
|
You can find and examine this file in the Build Directory in
|
|
<filename>tmp/work/</filename>.
|
|
The actual <filename>.config</filename> is located in the area where the
|
|
specific kernel is built.
|
|
For example, if you were building a Linux Yocto kernel based on the
|
|
Linux 3.4 kernel and you were building a QEMU image targeted for
|
|
<filename>x86</filename> architecture, the
|
|
<filename>.config</filename> file would be located here:
|
|
<literallayout class='monospaced'>
|
|
~/poky/build/tmp/work/qemux86-poky-linux/linux-yocto-3.4.11+git1+84f...
|
|
...656ed30-r1/linux-qemux86-standard-build
|
|
</literallayout>
|
|
<note>
|
|
The previous example directory is artificially split and many of the characters
|
|
in the actual filename are omitted in order to make it more readable.
|
|
Also, depending on the kernel you are using, the exact pathname
|
|
for <filename>linux-yocto-3.4...</filename> might differ.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
Within the <filename>.config</filename> file, you can see the kernel settings.
|
|
For example, the following entry shows that symmetric multi-processor support
|
|
is not set:
|
|
<literallayout class='monospaced'>
|
|
# CONFIG_SMP is not set
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
A good method to isolate changed configurations is to use a combination of the
|
|
<filename>menuconfig</filename> tool and simple shell commands.
|
|
Before changing configurations with <filename>menuconfig</filename>, copy the
|
|
existing <filename>.config</filename> and rename it to something else,
|
|
use <filename>menuconfig</filename> to make
|
|
as many changes an you want and save them, then compare the renamed configuration
|
|
file against the newly created file.
|
|
You can use the resulting differences as your base to create configuration fragments
|
|
to permanently save in your kernel layer.
|
|
<note>
|
|
Be sure to make a copy of the <filename>.config</filename> and don't just
|
|
rename it.
|
|
The build system needs an existing <filename>.config</filename>
|
|
from which to work.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='creating-config-fragments'>
|
|
<title>Creating Configuration Fragments</title>
|
|
|
|
<para>
|
|
Configuration fragments are simply kernel options that appear in a file
|
|
placed where the OpenEmbedded build system can find and apply them.
|
|
Syntactically, the configuration statement is identical to what would appear
|
|
in the <filename>.config</filename> file, which is in the
|
|
<link linkend='build-directory'>Build Directory</link> in
|
|
<filename>tmp/work/<arch>-poky-linux/linux-yocto-<release-specific-string>/linux-<arch>-<build-type></filename>.
|
|
</para>
|
|
|
|
<para>
|
|
It is simple to create a configuration fragment.
|
|
For example, issuing the following from the shell creates a configuration fragment
|
|
file named <filename>my_smp.cfg</filename> that enables multi-processor support
|
|
within the kernel:
|
|
<literallayout class='monospaced'>
|
|
$ echo "CONFIG_SMP=y" >> my_smp.cfg
|
|
</literallayout>
|
|
<note>
|
|
All configuration files must use the <filename>.cfg</filename> extension in order
|
|
for the OpenEmbedded build system to recognize them as a configuration fragment.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
Where do you put your configuration files?
|
|
You can place these configuration files in the same area pointed to by
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>.
|
|
The OpenEmbedded build system will pick up the configuration and add it to the
|
|
kernel's configuration.
|
|
For example, suppose you had a set of configuration options in a file called
|
|
<filename>myconfig.cfg</filename>.
|
|
If you put that file inside a directory named <filename>/linux-yocto</filename>
|
|
that resides in the same directory as the kernel's append file and then add
|
|
a <filename>SRC_URI</filename> statement such as the following to the kernel's append file,
|
|
those configuration options will be picked up and applied when the kernel is built.
|
|
<literallayout class='monospaced'>
|
|
SRC_URI += "file://myconfig.cfg"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
As mentioned earlier, you can group related configurations into multiple files and
|
|
name them all in the <filename>SRC_URI</filename> statement as well.
|
|
For example, you could group separate configurations specifically for Ethernet and graphics
|
|
into their own files and add those by using a <filename>SRC_URI</filename> statement like the
|
|
following in your append file:
|
|
<literallayout class='monospaced'>
|
|
SRC_URI += "file://myconfig.cfg \
|
|
file://eth.cfg \
|
|
file://gfx.cfg"
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='fine-tuning-the-kernel-configuration-file'>
|
|
<title>Fine-Tuning the Kernel Configuration File</title>
|
|
|
|
<para>
|
|
You can make sure the <filename>.config</filename> file is as lean or efficient as
|
|
possible by reading the output of the kernel configuration fragment audit,
|
|
noting any issues, making changes to correct the issues, and then repeating.
|
|
</para>
|
|
|
|
<para>
|
|
As part of the kernel build process, the
|
|
<filename>kernel_configcheck</filename> task runs.
|
|
This task validates the kernel configuration by checking the final
|
|
<filename>.config</filename> file against the input files.
|
|
During the check, the task produces warning messages for the following
|
|
issues:
|
|
<itemizedlist>
|
|
<listitem><para>Requested options that did not make the final
|
|
<filename>.config</filename> file.</para></listitem>
|
|
<listitem><para>Configuration items that appear twice in the same
|
|
configuration fragment.</para></listitem>
|
|
<listitem><para>Configuration items tagged as "required" were overridden.
|
|
</para></listitem>
|
|
<listitem><para>A board overrides a non-board specific option.</para></listitem>
|
|
<listitem><para>Listed options not valid for the kernel being processed.
|
|
In other words, the option does not appear anywhere.</para></listitem>
|
|
</itemizedlist>
|
|
<note>
|
|
The <filename>kernel_configcheck</filename> task can also optionally report
|
|
if an option is overridden during processing.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
For each output warning, a message points to the file
|
|
that contains a list of the options and a pointer to the config
|
|
fragment that defines them.
|
|
Collectively, the files are the key to streamlining the configuration.
|
|
</para>
|
|
|
|
<para>
|
|
To streamline the configuration, do the following:
|
|
<orderedlist>
|
|
<listitem><para>Start with a full configuration that you know
|
|
works - it builds and boots successfully.
|
|
This configuration file will be your baseline.</para></listitem>
|
|
<listitem><para>Separately run the <filename>configme</filename> and
|
|
<filename>kernel_configcheck</filename> tasks.</para></listitem>
|
|
<listitem><para>Take the resulting list of files from the
|
|
<filename>kernel_configcheck</filename> task warnings and do the following:
|
|
<itemizedlist>
|
|
<listitem><para>Drop values that are redefined in the fragment but do not
|
|
change the final <filename>.config</filename> file.</para></listitem>
|
|
<listitem><para>Analyze and potentially drop values from the
|
|
<filename>.config</filename> file that override required
|
|
configurations.</para></listitem>
|
|
<listitem><para>Analyze and potentially remove non-board specific options.
|
|
</para></listitem>
|
|
<listitem><para>Remove repeated and invalid options.</para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
<listitem><para>After you have worked through the output of the kernel configuration
|
|
audit, you can re-run the <filename>configme</filename>
|
|
and <filename>kernel_configcheck</filename> tasks to see the results of your
|
|
changes.
|
|
If you have more issues, you can deal with them as described in the
|
|
previous step.</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Iteratively working through steps two through four eventually yields
|
|
a minimal, streamlined configuration file.
|
|
Once you have the best <filename>.config</filename>, you can build the Linux
|
|
Yocto kernel.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="patching-the-kernel">
|
|
<title>Patching the Kernel</title>
|
|
|
|
<para>
|
|
Patching the kernel involves changing or adding configurations to an existing kernel,
|
|
changing or adding recipes to the kernel that are needed to support specific hardware features,
|
|
or even altering the source code itself.
|
|
<note>
|
|
You can use the <filename>yocto-kernel</filename> script
|
|
found in the <link linkend='source-directory'>Source Directory</link>
|
|
under <filename>scripts</filename> to manage kernel patches and configuration.
|
|
See the "<ulink url='&YOCTO_DOCS_BSP_URL;#managing-kernel-patches-and-config-items-with-yocto-kernel'>Managing kernel Patches and Config Items with yocto-kernel</ulink>"
|
|
section in the Yocto Project Board Support Packages (BSP) Developer's Guide for
|
|
more information.</note>
|
|
</para>
|
|
|
|
<para>
|
|
This example creates a simple patch by adding some QEMU emulator console
|
|
output at boot time through <filename>printk</filename> statements in the kernel's
|
|
<filename>calibrate.c</filename> source code file.
|
|
Applying the patch and booting the modified image causes the added
|
|
messages to appear on the emulator's console.
|
|
</para>
|
|
|
|
<para>
|
|
The example assumes a clean build exists for the <filename>qemux86</filename>
|
|
machine in a Source Directory named <filename>poky</filename>.
|
|
Furthermore, the <link linkend='build-directory'>Build Directory</link> is
|
|
<filename>build</filename> and is located in <filename>poky</filename> and
|
|
the kernel is based on the Linux 3.4 kernel.
|
|
For general information on how to configure the most efficient build, see the
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#building-image'>Building an Image</ulink>" section
|
|
in the Yocto Project Quick Start.
|
|
</para>
|
|
|
|
<para>
|
|
Also, for more information on patching the kernel, see the
|
|
"<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#applying-patches'>Applying Patches</ulink>"
|
|
section in the Yocto Project Linux Kernel Development Manual.
|
|
</para>
|
|
|
|
<section id='create-a-layer-for-your-changes'>
|
|
<title>Create a Layer for your Changes</title>
|
|
|
|
<para>
|
|
The first step is to create a layer so you can isolate your changes:
|
|
<literallayout class='monospaced'>
|
|
$cd ~/poky
|
|
$mkdir meta-mylayer
|
|
</literallayout>
|
|
Creating a directory that follows the Yocto Project layer naming
|
|
conventions sets up the layer for your changes.
|
|
The layer is where you place your configuration files, append
|
|
files, and patch files.
|
|
To learn more about creating a layer and filling it with the
|
|
files you need, see the "<link linkend='understanding-and-creating-layers'>Understanding
|
|
and Creating Layers</link>" section.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='finding-the-kernel-source-code'>
|
|
<title>Finding the Kernel Source Code</title>
|
|
|
|
<para>
|
|
Each time you build a kernel image, the kernel source code is fetched
|
|
and unpacked into the following directory:
|
|
<literallayout class='monospaced'>
|
|
${S}/linux
|
|
</literallayout>
|
|
See the "<link linkend='finding-the-temporary-source-code'>Finding the Temporary Source Code</link>"
|
|
section and the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-S'><filename>S</filename></ulink> variable
|
|
for more information about where source is kept during a build.
|
|
</para>
|
|
|
|
<para>
|
|
For this example, we are going to patch the
|
|
<filename>init/calibrate.c</filename> file
|
|
by adding some simple console <filename>printk</filename> statements that we can
|
|
see when we boot the image using QEMU.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='creating-the-patch'>
|
|
<title>Creating the Patch</title>
|
|
|
|
<para>
|
|
Two methods exist by which you can create the patch:
|
|
<link linkend='using-a-git-workflow'>Git workflow</link> and
|
|
<link linkend='using-a-quilt-workflow'>Quilt workflow</link>.
|
|
For kernel patches, the Git workflow is more appropriate.
|
|
This section assumes the Git workflow and shows the steps specific to
|
|
this example.
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Change the working directory</emphasis>:
|
|
Change to where the kernel source code is before making
|
|
your edits to the <filename>calibrate.c</filename> file:
|
|
<literallayout class='monospaced'>
|
|
$ cd ~/poky/build/tmp/work/qemux86-poky-linux/linux-yocto-${PV}-${PR}/linux
|
|
</literallayout>
|
|
Because you are working in an established Git repository,
|
|
you must be in this directory in order to commit your changes
|
|
and create the patch file.
|
|
<note>The <ulink url='&YOCTO_DOCS_REF_URL;#var-PV'><filename>PV</filename></ulink> and
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PR'><filename>PR</filename></ulink> variables
|
|
represent the version and revision for the
|
|
<filename>linux-yocto</filename> recipe.
|
|
The <filename>PV</filename> variable includes the Git meta and machine
|
|
hashes, which make the directory name longer than you might
|
|
expect.
|
|
</note></para></listitem>
|
|
<listitem><para><emphasis>Edit the source file</emphasis>:
|
|
Edit the <filename>init/calibrate.c</filename> file to have the
|
|
following changes:
|
|
<literallayout class='monospaced'>
|
|
void __cpuinit calibrate_delay(void)
|
|
{
|
|
unsigned long lpj;
|
|
static bool printed;
|
|
int this_cpu = smp_processor_id();
|
|
|
|
printk("*************************************\n");
|
|
printk("* *\n");
|
|
printk("* HELLO YOCTO KERNEL *\n");
|
|
printk("* *\n");
|
|
printk("*************************************\n");
|
|
|
|
if (per_cpu(cpu_loops_per_jiffy, this_cpu)) {
|
|
.
|
|
.
|
|
.
|
|
</literallayout></para></listitem>
|
|
<listitem><para><emphasis>Stage and commit your changes</emphasis>:
|
|
These Git commands display the modified file, stage it, and then
|
|
commit the file:
|
|
<literallayout class='monospaced'>
|
|
$ git status
|
|
$ git add init/calibrate.c
|
|
$ git commit -m "calibrate: Add printk example"
|
|
</literallayout></para></listitem>
|
|
<listitem><para><emphasis>Generate the patch file</emphasis>:
|
|
This Git command creates the a patch file named
|
|
<filename>0001-calibrate-Add-printk-example.patch</filename>
|
|
in the current directory.
|
|
<literallayout class='monospaced'>
|
|
$ git format-patch -1
|
|
</literallayout>
|
|
</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='set-up-your-layer-for-the-build'>
|
|
<title>Set Up Your Layer for the Build</title>
|
|
|
|
<para>These steps get your layer set up for the build:
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Create additional structure</emphasis>:
|
|
Create the additional layer structure:
|
|
<literallayout class='monospaced'>
|
|
$ cd ~/poky/meta-mylayer
|
|
$ mkdir conf
|
|
$ mkdir recipes-kernel
|
|
$ mkdir recipes-kernel/linux
|
|
$ mkdir recipes-kernel/linux/linux-yocto
|
|
</literallayout>
|
|
The <filename>conf</filename> directory holds your configuration files, while the
|
|
<filename>recipes-kernel</filename> directory holds your append file and
|
|
your patch file.</para></listitem>
|
|
<listitem><para><emphasis>Create the layer configuration file</emphasis>:
|
|
Move to the <filename>meta-mylayer/conf</filename> directory and create
|
|
the <filename>layer.conf</filename> file as follows:
|
|
<literallayout class='monospaced'>
|
|
# We have a conf and classes directory, add to BBPATH
|
|
BBPATH .= ":${LAYERDIR}"
|
|
|
|
# We have recipes-* directories, add to BBFILES
|
|
BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
|
|
${LAYERDIR}/recipes-*/*/*.bbappend"
|
|
|
|
BBFILE_COLLECTIONS += "mylayer"
|
|
BBFILE_PATTERN_mylayer = "^${LAYERDIR}/"
|
|
BBFILE_PRIORITY_mylayer = "5"
|
|
</literallayout>
|
|
Notice <filename>mylayer</filename> as part of the last three
|
|
statements.</para></listitem>
|
|
<listitem><para><emphasis>Create the kernel recipe append file</emphasis>:
|
|
Move to the <filename>meta-mylayer/recipes-kernel/linux</filename> directory and create
|
|
the <filename>linux-yocto_3.4.bbappend</filename> file as follows:
|
|
<literallayout class='monospaced'>
|
|
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
|
|
|
|
SRC_URI += "file://0001-calibrate-Add-printk-example.patch"
|
|
|
|
PRINC := "${@int(PRINC) + 1}"
|
|
</literallayout>
|
|
The <ulink url='&YOCTO_DOCS_REF_URL;#var-FILESEXTRAPATHS'><filename>FILESEXTRAPATHS</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
statements enable the OpenEmbedded build system to find the patch file.
|
|
For more information on using append files, see the
|
|
"<link linkend='using-bbappend-files'>Using .bbappend Files</link>"
|
|
section.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Put the patch file in your layer</emphasis>:
|
|
Move the <filename>0001-calibrate-Add-printk-example.patch</filename> file to
|
|
the <filename>meta-mylayer/recipes-kernel/linux/linux-yocto</filename>
|
|
directory.</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='set-up-for-the-build'>
|
|
<title>Set Up for the Build</title>
|
|
|
|
<para>
|
|
Do the following to make sure the build parameters are set up for the example.
|
|
Once you set up these build parameters, they do not have to change unless you
|
|
change the target architecture of the machine you are building:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Build for the correct target architecture:</emphasis> Your
|
|
selected <ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'><filename>MACHINE</filename></ulink>
|
|
definition within the <filename>local.conf</filename> file in the
|
|
<link linkend='build-directory'>Build Directory</link>
|
|
specifies the target architecture used when building the Linux kernel.
|
|
By default, <filename>MACHINE</filename> is set to
|
|
<filename>qemux86</filename>, which specifies a 32-bit
|
|
<trademark class='registered'>Intel</trademark> Architecture
|
|
target machine suitable for the QEMU emulator.</para></listitem>
|
|
<listitem><para><emphasis>Identify your <filename>meta-mylayer</filename>
|
|
layer:</emphasis> The
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBLAYERS'><filename>BBLAYERS</filename></ulink>
|
|
variable in the
|
|
<filename>bblayers.conf</filename> file found in the
|
|
<filename>poky/build/conf</filename> directory needs to have the path to your local
|
|
<filename>meta-mylayer</filename> layer.
|
|
By default, the <filename>BBLAYERS</filename> variable contains paths to
|
|
<filename>meta</filename>, <filename>meta-yocto</filename>, and
|
|
<filename>meta-yocto-bsp</filename> in the
|
|
<filename>poky</filename> Git repository.
|
|
Add the path to your <filename>meta-mylayer</filename> location:
|
|
<literallayout class='monospaced'>
|
|
BBLAYERS ?= " \
|
|
$HOME/poky/meta \
|
|
$HOME/poky/meta-yocto \
|
|
$HOME/poky/meta-yocto-bsp \
|
|
$HOME/poky/meta-mylayer \
|
|
"
|
|
|
|
BBLAYERS_NON_REMOVABLE ?= " \
|
|
$HOME/poky/meta \
|
|
$HOME/poky/meta-yocto \
|
|
"
|
|
</literallayout></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='build-the-modified-qemu-kernel-image'>
|
|
<title>Build the Modified QEMU Kernel Image</title>
|
|
|
|
<para>
|
|
The following steps build your modified kernel image:
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Be sure your build environment is initialized</emphasis>:
|
|
Your environment should be set up since you previously sourced
|
|
the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>&OE_INIT_FILE;</filename></ulink>
|
|
script.
|
|
If it is not, source the script again from <filename>poky</filename>.
|
|
<literallayout class='monospaced'>
|
|
$ cd ~/poky
|
|
$ source &OE_INIT_FILE;
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Clean up</emphasis>:
|
|
Be sure to clean the shared state out by running the
|
|
<filename>cleansstate</filename> BitBake task as follows from your Build Directory:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -c cleansstate linux-yocto
|
|
</literallayout></para>
|
|
<para><note>Never remove any files by hand from the <filename>tmp/deploy</filename>
|
|
directory inside the
|
|
<link linkend='build-directory'>Build Directory</link>.
|
|
Always use the various BitBake clean tasks to clear out previous
|
|
build artifacts.
|
|
</note></para></listitem>
|
|
<listitem><para><emphasis>Build the image</emphasis>:
|
|
Next, build the kernel image using this command:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake -k linux-yocto
|
|
</literallayout></para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='boot-the-image-and-verify-your-changes'>
|
|
<title>Boot the Image and Verify Your Changes</title>
|
|
|
|
<para>
|
|
These steps boot the image and allow you to see the changes
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Boot the image</emphasis>:
|
|
Boot the modified image in the QEMU emulator
|
|
using this command:
|
|
<literallayout class='monospaced'>
|
|
$ runqemu qemux86
|
|
</literallayout></para></listitem>
|
|
<listitem><para><emphasis>Verify the changes</emphasis>:
|
|
Log into the machine using <filename>root</filename> with no password and then
|
|
use the following shell command to scroll through the console's boot output.
|
|
<literallayout class='monospaced'>
|
|
# dmesg | less
|
|
</literallayout>
|
|
You should see the results of your <filename>printk</filename> statements
|
|
as part of the output.</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='creating-your-own-distribution'>
|
|
<title>Creating Your Own Distribution</title>
|
|
|
|
<para>
|
|
When you build an image using the Yocto Project and
|
|
do not alter any distribution
|
|
<link linkend='metadata'>Metadata</link>, you are creating a
|
|
Poky distribution.
|
|
If you wish to gain more control over package alternative
|
|
selections, compile-time options, and other low-level
|
|
configurations, you can create your own distribution.
|
|
</para>
|
|
|
|
<para>
|
|
To create your own distribution, the basic steps consist of
|
|
creating your own distribution layer, creating your own
|
|
distribution configuration file, and then adding any needed
|
|
code and Metadata to the layer.
|
|
The following steps provide some more detail:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Create a layer for your new distro:</emphasis>
|
|
Create your distribution layer so that you can keep your
|
|
Metadata and code for the distribution separate.
|
|
It is strongly recommended that you create and use your own
|
|
layer for configuration and code.
|
|
Using your own layer as compared to just placing
|
|
configurations in a <filename>local.conf</filename>
|
|
configuration file makes it easier to reproduce the same
|
|
build configuration when using multiple build machines.
|
|
See the
|
|
"<link linkend='creating-a-general-layer-using-the-yocto-layer-script'>Creating a General Layer Using the yocto-layer Script</link>"
|
|
section for information on how to quickly set up a layer.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Create the distribution configuration file:</emphasis>
|
|
The distribution configuration file needs to be created in
|
|
the <filename>conf/distro</filename> directory of your
|
|
layer.
|
|
You need to name it using your distribution name
|
|
(e.g. <filename>mydistro.conf</filename>).</para>
|
|
<para>You can split out parts of your configuration file
|
|
into include files and then "require" them from within
|
|
your distribution configuration file.
|
|
Be sure to place the include files in the
|
|
<filename>conf/distro/include</filename> directory of
|
|
your layer.
|
|
A common example usage of include files would be to
|
|
separate out the selection of desired version and revisions
|
|
for individual recipes.
|
|
</para>
|
|
<para>Your configuration file needs to set the following
|
|
required variables:
|
|
<literallayout class='monospaced'>
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_NAME'><filename>DISTRO_NAME</filename></ulink> [required]
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_VERSION'><filename>DISTRO_VERSION</filename></ulink> [required]
|
|
</literallayout>
|
|
These following variables are optional and you typically
|
|
set them from the distribution configuration file:
|
|
<literallayout class='monospaced'>
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink> [optional]
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_EXTRA_RDEPENDS'><filename>DISTRO_EXTRA_RDEPENDS</filename></ulink> [optional]
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_EXTRA_RRECOMMENDS'><filename>DISTRO_EXTRA_RRECOMMENDS</filename></ulink> [optional]
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-TCLIBC'><filename>TCLIBC</filename></ulink> [optional]
|
|
</literallayout>
|
|
<tip>
|
|
If you want to base your distribution configuration file
|
|
on the very basic configuration from OE-Core, you
|
|
can use
|
|
<filename>conf/distro/defaultsetup.conf</filename> as
|
|
a reference and just include variables that differ
|
|
as compared to <filename>defaultsetup.conf</filename>.
|
|
Alternatively, you can create a distribution
|
|
configuration file from scratch using the
|
|
<filename>defaultsetup.conf</filename> file
|
|
or configuration files from other distributions
|
|
such as Poky or Angstrom as references.
|
|
</tip></para></listitem>
|
|
<listitem><para><emphasis>Provide miscellaneous variables:</emphasis>
|
|
Be sure to define any other variables for which you want to
|
|
create a default or enforce as part of the distribution
|
|
configuration.
|
|
You can include nearly any variable from the
|
|
<filename>local.conf</filename> file.
|
|
The variables you use are not limited to the list in the
|
|
previous bulleted item.</para></listitem>
|
|
<listitem><para><emphasis>Point to Your distribution configuration file:</emphasis>
|
|
In your <filename>local.conf</filename> file in the
|
|
<link linkend='build-directory'>Build Directory</link>,
|
|
set your
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO'><filename>DISTRO</filename></ulink>
|
|
variable to point to your distribution's configuration file.
|
|
For example, if your distribution's configuration file is
|
|
named <filename>mydistro.conf</filename>, then you point
|
|
to it as follows:
|
|
<literallayout class='monospaced'>
|
|
DISTRO = "mydistro"
|
|
</literallayout></para></listitem>
|
|
<listitem><para><emphasis>Add more to the layer if necessary:</emphasis>
|
|
Use your layer to hold other information needed for the
|
|
distribution:
|
|
<itemizedlist>
|
|
<listitem><para>Add recipes for installing
|
|
distro-specific configuration files that are not
|
|
already installed by another recipe.
|
|
If you have distro-specific configuration files
|
|
that are included by an existing recipe, you should
|
|
add a <filename>.bbappend</filename> for those.
|
|
For general information and recommendations
|
|
on how to add recipes to your layer, see the
|
|
"<link linkend='creating-your-own-layer'>Creating Your Own Layer</link>"
|
|
and
|
|
"<link linkend='best-practices-to-follow-when-creating-layers'>Best Practices to Follow When Creating Layers</link>"
|
|
sections.</para></listitem>
|
|
<listitem><para>Add any image recipes that are specific
|
|
to your distribution.</para></listitem>
|
|
<listitem><para>Add a <filename>psplash</filename>
|
|
append file for a branded splash screen.
|
|
For information on append files, see the
|
|
"<link linkend='using-bbappend-files'>Using .bbappend Files</link>"
|
|
section.</para></listitem>
|
|
<listitem><para>Add any other append files to make
|
|
custom changes that are specific to individual
|
|
recipes.</para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='building-a-tiny-system'>
|
|
<title>Building a Tiny System</title>
|
|
|
|
<para>
|
|
Very small distributions have some significant advantages such
|
|
as requiring less on-die or in-package memory (cheaper), better
|
|
performance through efficient cache usage, lower power requirements
|
|
due to less memory, faster boot times, and reduced development
|
|
overhead.
|
|
Some real-world examples where a very small distribution gives
|
|
you distinct advantages are digital cameras, medical devices,
|
|
and small headless systems.
|
|
</para>
|
|
|
|
<para>
|
|
This section presents information that shows you how you can
|
|
trim your distribution to even smaller sizes than the
|
|
<filename>poky-tiny</filename> distribution, which is around
|
|
5 Mbytes, that can be built out-of-the-box using the Yocto Project.
|
|
</para>
|
|
|
|
<section id='tiny-system-overview'>
|
|
<title>Overview</title>
|
|
|
|
<para>
|
|
The following list presents the overall steps you need to
|
|
consider and perform to create distributions with smaller
|
|
root filesystems, faster boot times, maintain your critical
|
|
functionality, and avoid initial RAM disks:
|
|
<itemizedlist>
|
|
<listitem><para>Determine your goals and guiding
|
|
principles.</para></listitem>
|
|
<listitem><para>Understand what gives your image size.
|
|
</para></listitem>
|
|
<listitem><para>Reduce the size of the root filesystem.
|
|
</para></listitem>
|
|
<listitem><para>Reduce the size of the kernel.
|
|
</para></listitem>
|
|
<listitem><para>Eliminate packaging requirements.
|
|
</para></listitem>
|
|
<listitem><para>Look for other ways to minimize size.
|
|
</para></listitem>
|
|
<listitem><para>Iterate on the process.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='goals-and-guiding-principles'>
|
|
<title>Goals and Guiding Principles</title>
|
|
|
|
<para>
|
|
Before you can reach your destination, you need to know
|
|
where you are going.
|
|
Here is an example list that you can use as a guide when
|
|
creating very small distributions:
|
|
<itemizedlist>
|
|
<listitem><para>Determine how much space you need
|
|
(e.g. a kernel that is 1 Mbyte or less and
|
|
a root filesystem that is 3 Mbytes or less).
|
|
</para></listitem>
|
|
<listitem><para>Find the areas that are currently
|
|
taking 90% of the space and concentrate on reducing
|
|
those areas.
|
|
</para></listitem>
|
|
<listitem><para>Do not create any difficult "hacks"
|
|
to achieve your goals.</para></listitem>
|
|
<listitem><para>Leverage the device-specific
|
|
options.</para></listitem>
|
|
<listitem><para>Work in a separate layer so that you
|
|
keep changes isolated.
|
|
For information on how to create layers, see
|
|
the "<link linkend='understanding-and-creating-layers'>Understanding and Creating Layers</link>" section.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='understand-what-gives-your-image-size'>
|
|
<title>Understand What Gives Your Image Size</title>
|
|
|
|
<para>
|
|
It is easiest to have something to start with when creating
|
|
your own distribution.
|
|
You can use the Yocto Project out-of-the-box to create the
|
|
<filename>poky-tiny</filename> distribution.
|
|
Ultimately, you will want to make changes in your own
|
|
distribution that are likely modeled after
|
|
<filename>poky-tiny</filename>.
|
|
<note>
|
|
To use <filename>poky-tiny</filename> in your build,
|
|
set the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO'><filename>DISTRO</filename></ulink>
|
|
variable in your
|
|
<filename>local.conf</filename> file to "poky-tiny"
|
|
as described in the
|
|
"<link linkend='creating-your-own-distribution'>Creating Your Own Distribution</link>"
|
|
section.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
Understanding some memory concepts will help you reduce the
|
|
system size.
|
|
Memory consists of static, dynamic, and temporary memory.
|
|
Static memory is the TEXT (code), DATA (initialized data
|
|
in the code), and BSS (uninitialized data) sections.
|
|
Dynamic memory contains memory that is allocated at runtime,
|
|
stacks, hash tables, and so forth.
|
|
Temporary memory is recovered after the boot process.
|
|
This memory consists of memory used for decompressing
|
|
the kernel and for the <filename>__init__</filename>
|
|
functions.
|
|
</para>
|
|
|
|
<para>
|
|
To help you see where you currently are with kernel and root
|
|
filesystem sizes, you can use two tools found in the
|
|
<link linkend='source-directory'>Source Directory</link> in
|
|
the <filename>scripts</filename> directory:
|
|
<itemizedlist>
|
|
<listitem><para><filename>ksize.py</filename>: Reports
|
|
component sizes for the kernel build objects.
|
|
</para></listitem>
|
|
<listitem><para><filename>dirsize.py</filename>: Reports
|
|
component sizes for the root filesystem.</para></listitem>
|
|
</itemizedlist>
|
|
This next tool and command helps you organize configuration
|
|
fragments and view file dependencies in a human-readable form:
|
|
<itemizedlist>
|
|
<listitem><para><filename>merge_config.sh</filename>:
|
|
Helps you manage configuration files and fragments
|
|
within the kernel.
|
|
With this tool, you can merge individual configuration
|
|
fragments together.
|
|
The tool allows you to make overrides and warns you
|
|
of any missing configuration options.
|
|
The tool is ideal for allowing you to iterate on
|
|
configurations, create minimal configurations, and
|
|
create configuration files for different machines
|
|
without having to duplicate your process.</para>
|
|
<para>The <filename>merge_config.sh</filename> script is
|
|
part of the Linux Yocto kernel Git repository in the
|
|
<filename>scripts/kconfig</filename> directory.</para>
|
|
<para>For more information on configuration fragments,
|
|
see the
|
|
"<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#generating-configuration-files'>Generating Configuration Files</ulink>"
|
|
section of the Yocto Project Linux Kernel Development
|
|
Manual and the "<link linkend='creating-config-fragments'>Creating Configuration Fragments</link>"
|
|
section, which is in this manual.</para></listitem>
|
|
<listitem><para><filename>bitbake -u depexp -g <bitbake_target></filename>:
|
|
Using the BitBake command with these options brings up
|
|
a Dependency Explorer from which you can view file
|
|
dependencies.
|
|
Understanding these dependencies allows you to make
|
|
informed decisions when cutting out various pieces of the
|
|
kernel and root filesystem.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='trim-the-root-filesystem'>
|
|
<title>Trim the Root Filesystem</title>
|
|
|
|
<para>
|
|
The root filesystem is made up of packages for booting,
|
|
libraries, and applications.
|
|
To change things, you can configure how the packaging happens,
|
|
which changes the way you build them.
|
|
You can also tweak the filesystem itself or select a different
|
|
filesystem.
|
|
</para>
|
|
|
|
<para>
|
|
First, find out what is hogging your root filesystem by running the
|
|
<filename>dirsize.py</filename> script from your root directory:
|
|
<literallayout class='monospaced'>
|
|
$ cd <root-directory-of-image>
|
|
$ dirsize.py 100000 > dirsize-100k.log
|
|
$ cat dirsize-100k.log
|
|
</literallayout>
|
|
You can apply a filter to the script to ignore files under
|
|
a certain size.
|
|
This example filters out anything below 100 Kbytes.
|
|
The sizes reported by the tool are uncompressed and thus,
|
|
will be smaller by a relatively constant factor in a
|
|
compressed root filesystem.
|
|
When you examine your log file, you can focus on areas of the
|
|
root filesystem that take up large amounts of memory.
|
|
</para>
|
|
|
|
<para>
|
|
You need to be sure that what you eliminate does not cripple
|
|
the functionality you need.
|
|
One way to see how packages relate to each other is by using
|
|
the Dependency Explorer UI with the BitBake command:
|
|
<literallayout class='monospaced'>
|
|
$ cd <image-directory>
|
|
$ bitbake -u depexp -g <image>
|
|
</literallayout>
|
|
Use the interface to select potential packages you wish to
|
|
eliminate and see their dependency relationships.
|
|
</para>
|
|
|
|
<para>
|
|
When deciding how to reduce the size, get rid of packages that
|
|
result in minimal impact on the feature set.
|
|
For example, you might not need a VGA display.
|
|
Or, you might be able to get by with <filename>devtmpfs</filename>
|
|
and <filename>mdev</filename> instead of
|
|
<filename>udev</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
Use the <filename>local.conf</filename> file to make changes.
|
|
For example, to eliminate <filename>udev</filename> and
|
|
<filename>glib</filename>, set the following in the
|
|
local configuration file:
|
|
<literallayout class='monospaced'>
|
|
VIRTUAL-RUNTIME_dev_manager = ""
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
Finally, you should consider exactly the type of root
|
|
filesystem you need to meet your needs while also reducing
|
|
its size.
|
|
For example, consider <filename>cramfs</filename>,
|
|
<filename>squashfs</filename>, <filename>ubifs</filename>,
|
|
<filename>ext2</filename>, or an <filename>initramfs</filename>
|
|
using <filename>initramfs</filename>.
|
|
Be aware that <filename>ext3</filename> requires a 1 Mbyte
|
|
journal.
|
|
If you are okay with running read-only you do not need this
|
|
journal.
|
|
</para>
|
|
|
|
<note>
|
|
After each round of elimination, you need to rebuild your
|
|
system and then use the tools to see the effects of your
|
|
reductions.
|
|
</note>
|
|
|
|
|
|
</section>
|
|
|
|
<section id='trim-the-kernel'>
|
|
<title>Trim the Kernel</title>
|
|
|
|
<para>
|
|
The kernel is built by including policies for hardware-independent
|
|
aspects.
|
|
What subsystems do you enable?
|
|
For what architecture are you building?
|
|
Which drivers do you build by default.
|
|
<note>You can modify the kernel source if you want to help
|
|
with boot time.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
Run the <filename>ksize.py</filename> script from the top-level
|
|
Linux build directory to get an idea of what is making up
|
|
the kernel:
|
|
<literallayout class='monospaced'>
|
|
$ cd <top-level-linux-build-directory>
|
|
$ ksize.py > ksize.log
|
|
$ cat ksize.log
|
|
</literallayout>
|
|
When you examine the log, you will see how much space is
|
|
taken up with the built-in <filename>.o</filename> files for
|
|
drivers, networking, core kernel files, filesystem, sound,
|
|
and so forth.
|
|
The sizes reported by the tool are uncompressed and thus,
|
|
will be smaller by a relatively constant factor in a compressed
|
|
kernel image.
|
|
Look to reduce the areas that are large and taking up around
|
|
the "90% rule."
|
|
</para>
|
|
|
|
<para>
|
|
To examine, or drill down, into any particular area, use the
|
|
<filename>-d</filename> option with the script:
|
|
<literallayout class='monospaced'>
|
|
$ ksize.py -d > ksize.log
|
|
</literallayout>
|
|
Using this option breaks out the individual file information
|
|
for each area of the kernel (e.g. drivers, networking, and
|
|
so forth).
|
|
</para>
|
|
|
|
<para>
|
|
Use your log file to see what you can eliminate from the kernel
|
|
based on features you can let go.
|
|
For example, if you are not going to need sound, you do not
|
|
need any drivers that support sound.
|
|
</para>
|
|
|
|
<para>
|
|
After figuring out what to eliminate, you need to reconfigure
|
|
the kernel to reflect those changes during the next build.
|
|
You could run <filename>menuconfig</filename> and make all your
|
|
changes at once.
|
|
However, that makes it difficult to see the effects of your
|
|
individual eliminations and also makes it difficult to replicate
|
|
the changes for perhaps another target device.
|
|
A better method is to start with no configurations using
|
|
<filename>allnoconfig</filename>, create configuration
|
|
fragments for individual changes, and then manage the
|
|
fragments into a single configuration file using
|
|
<filename>merge_config.sh</filename>.
|
|
The tool makes it easy for you to iterate using the
|
|
configuration change and build cycle.
|
|
</para>
|
|
|
|
<para>
|
|
Each time you make configuration changes, you need to rebuild
|
|
the kernel and check to see what impact your changes had on
|
|
the overall size.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='remove-package-management-requirements'>
|
|
<title>Remove Package Management Requirements</title>
|
|
|
|
<para>
|
|
Packaging requirements add size to the image.
|
|
One way to reduce the size of the image is to remove all the
|
|
packaging requirements from the image.
|
|
This reduction includes both removing the package manager
|
|
and its unique dependencies as well as removing the package
|
|
management data itself.
|
|
</para>
|
|
|
|
<para>
|
|
To eliminate all the packaging requirements for an image,
|
|
follow these steps:
|
|
<orderedlist>
|
|
<listitem><para>Put the following line in your main
|
|
recipe for the image to remove package management
|
|
data files:
|
|
<literallayout class='monospaced'>
|
|
ROOTFS_POSTPROCESS_COMMAND += "remove_packaging_data_files ;
|
|
</literallayout>
|
|
For example, the recipe for the
|
|
<filename>core-image-minimal</filename> image contains
|
|
this line.
|
|
You can also add the line to the
|
|
<filename>local.conf</filename> configuration file.
|
|
</para></listitem>
|
|
<listitem><para>Be sure that "package-management" is not
|
|
part of your
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></ulink>
|
|
statement for the image.
|
|
When you remove this feature, you are removing the
|
|
package manager as well as its dependencies
|
|
from the root filesystem.
|
|
</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='look-for-other-ways-to-minimize-size'>
|
|
<title>Look for Other Ways to Minimize Size</title>
|
|
|
|
<para>
|
|
Depending on your particular circumstances, other areas that you
|
|
can trim likely exist.
|
|
The key to finding these areas is through tools and methods
|
|
described here combined with experimentation and iteration.
|
|
Here are a couple of areas to experiment with:
|
|
<itemizedlist>
|
|
<listitem><para><filename>eglibc</filename>:
|
|
In general, follow this process:
|
|
<orderedlist>
|
|
<listitem><para>Remove <filename>eglibc</filename>
|
|
features from
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink>
|
|
that you think you do not need.</para></listitem>
|
|
<listitem><para>Build your distribution.
|
|
</para></listitem>
|
|
<listitem><para>If the build fails due to missing
|
|
symbols in a package, determine if you can
|
|
reconfigure the package to not need those
|
|
features.
|
|
For example, change the configuration to not
|
|
support wide character support as is done for
|
|
<filename>ncurses</filename>.
|
|
Or, if support for those characters is needed,
|
|
determine what <filename>eglibc</filename>
|
|
features provide the support and restore the
|
|
configuration.
|
|
</para></listitem>
|
|
<listitem><para>Rebuild and repeat the process.
|
|
</para></listitem>
|
|
</orderedlist></para></listitem>
|
|
<listitem><para><filename>busybox</filename>:
|
|
For BusyBox, use a process similar as described for
|
|
<filename>eglibc</filename>.
|
|
A difference is you will need to boot the resulting
|
|
system to see if you are able to do everything you
|
|
expect from the running system.
|
|
You need to be sure to integrate configuration fragments
|
|
into Busybox because BusyBox handles its own core
|
|
features and then allows you to add configuration
|
|
fragments on top.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='iterate-on-the-process'>
|
|
<title>Iterate on the Process</title>
|
|
|
|
<para>
|
|
If you have not reached your goals on system size, you need
|
|
to iterate on the process.
|
|
The process is the same.
|
|
Use the tools and see just what is taking up 90% of the root
|
|
filesystem and the kernel.
|
|
Decide what you can eliminate without limiting your device
|
|
beyond what you need.
|
|
</para>
|
|
|
|
<para>
|
|
Depending on your system, a good place to look might be
|
|
Busybox, which provides a stripped down
|
|
version of Unix tools in a single, executable file.
|
|
You might be able to drop virtual terminal services or perhaps
|
|
ipv6.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='working-with-packages'>
|
|
<title>Working with Packages</title>
|
|
|
|
<para>
|
|
This section describes a few tasks that involve packages:
|
|
<itemizedlist>
|
|
<listitem><para>Excluding packages from an image
|
|
</para></listitem>
|
|
<listitem><para>Incrementing a package revision number
|
|
</para></listitem>
|
|
<listitem><para>Handling a package name alias
|
|
</para></listitem>
|
|
<listitem><para>Handling optional module packaging
|
|
</para></listitem>
|
|
<listitem><para>Using Runtime Package Management
|
|
</para></listitem>
|
|
<listitem><para>Setting up and running package test
|
|
(ptest)
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<section id='excluding-packages-from-an-image'>
|
|
<title>Excluding Packages from an Image</title>
|
|
|
|
<para>
|
|
You might find it necessary to prevent specific packages
|
|
from being installed into an image.
|
|
If so, you can use several variables to direct the build
|
|
system to essentially ignore installing recommended packages
|
|
or to not install a package at all.
|
|
</para>
|
|
|
|
<para>
|
|
The following list introduces variables you can use to
|
|
prevent packages from being installed into your image.
|
|
Each of these variables only works with IPK and RPM
|
|
package types.
|
|
Support for Debian packages does not exist.
|
|
Also, you can use these variables from your
|
|
<filename>local.conf</filename> file or attach them to a
|
|
specific image recipe by using a recipe name override.
|
|
For more detail on the variables, see the descriptions in the
|
|
Yocto Project Reference Manual's glossary chapter.
|
|
<itemizedlist>
|
|
<listitem><para><ulink url='&YOCTO_DOCS_REF_URL;#var-BAD_RECOMMENDATIONS'><filename>BAD_RECOMMENDATIONS</filename></ulink>:
|
|
Use this variable to specify "recommended-only"
|
|
packages that you do not want installed.
|
|
</para></listitem>
|
|
<listitem><para><ulink url='&YOCTO_DOCS_REF_URL;#var-NO_RECOMMENDATIONS'><filename>NO_RECOMMENDATIONS</filename></ulink>:
|
|
Use this variable to prevent all "recommended-only"
|
|
packages from being installed.
|
|
</para></listitem>
|
|
<listitem><para><ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGE_EXCLUDE'><filename>PACKAGE_EXCLUDE</filename></ulink>:
|
|
Use this variable to prevent specific packages from
|
|
being installed regardless of whether they are
|
|
"recommended-only" or not.
|
|
You need to realize that the build process could
|
|
fail with an error when you
|
|
prevent the installation of a package whose presence
|
|
is required by an installed package.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='incrementing-a-package-revision-number'>
|
|
<title>Incrementing a Package Revision Number</title>
|
|
|
|
<para>
|
|
If a committed change results in changing the package output,
|
|
then the value of the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PR'><filename>PR</filename></ulink>
|
|
variable needs to be increased (or "bumped").
|
|
Increasing <filename>PR</filename> occurs one of two ways:
|
|
<itemizedlist>
|
|
<listitem><para>Automatically using a Package Revision
|
|
Service (PR Service).</para></listitem>
|
|
<listitem><para>Manually incrementing the
|
|
<filename>PR</filename> variable.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Given that one of the challenges any build system and its
|
|
users face is how to maintain a package feed that is compatible
|
|
with existing package manager applications such as
|
|
RPM, APT, and OPKG, using an automated system is much
|
|
preferred over a manual system.
|
|
In either system, the main requirement is that version
|
|
numbering increases in a linear fashion and that a number of
|
|
version components exist that support that linear progression.
|
|
</para>
|
|
|
|
<para>
|
|
The following two sections provide information on the PR Service
|
|
and on manual <filename>PR</filename> bumping.
|
|
</para>
|
|
|
|
<section id='working-with-a-pr-service'>
|
|
<title>Working With a PR Service</title>
|
|
|
|
<para>
|
|
As mentioned, attempting to maintain revision numbers in the
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink>
|
|
is error prone, inaccurate and causes problems for people
|
|
submitting recipes.
|
|
Conversely, the PR Service automatically generates
|
|
increasing numbers, particularly the revision field,
|
|
which removes the human element.
|
|
<note>
|
|
For additional information on using a PR Service, you
|
|
can see the
|
|
<ulink url='&YOCTO_WIKI_URL;/wiki/PR_Service'>PR Service</ulink>
|
|
wiki page.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
The Yocto Project uses variables in order of
|
|
decreasing priority to facilitate revision numbering (i.e.
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PE'><filename>PE</filename></ulink>,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PV'><filename>PV</filename></ulink>, and
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PR'><filename>PR</filename></ulink>
|
|
for epoch, version and revision, respectively).
|
|
The values are highly dependent on the policies and
|
|
procedures of a given distribution and package feed.
|
|
</para>
|
|
|
|
<para>
|
|
Because the OpenEmbedded build system uses
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#checksums'>signatures</ulink>",
|
|
which are unique to a given build, the build system
|
|
knows when to rebuild packages.
|
|
All the inputs into a given task are represented by a
|
|
signature, which can trigger a rebuild when different.
|
|
Thus, the build system itself does not rely on the
|
|
<filename>PR</filename> numbers to trigger a rebuild.
|
|
The signatures, however, can be used to generate
|
|
<filename>PR</filename> values.
|
|
</para>
|
|
|
|
<para>
|
|
The PR Service works with both
|
|
<filename>OEBasic</filename> and
|
|
<filename>OEBasicHash</filename> generators.
|
|
The value of <filename>PR</filename> bumps when the
|
|
checksum changes and the different generator mechanisms
|
|
change signatures under different circumstances.
|
|
</para>
|
|
|
|
<para>
|
|
As implemented, the build system includes values from
|
|
the PR Service into the <filename>PR</filename> field as
|
|
an addition using the form "<filename>.x</filename>" so
|
|
<filename>r0</filename> becomes <filename>r0.1</filename>,
|
|
<filename>r0.2</filename> and so forth.
|
|
This scheme allows existing <filename>PR</filename> values
|
|
to be used for whatever reasons, which include manual
|
|
<filename>PR</filename> bumps should it be necessary.
|
|
</para>
|
|
|
|
<para>
|
|
By default, the PR Service is not enabled or running.
|
|
Thus, the packages generated are just "self consistent".
|
|
The build system adds and removes packages and
|
|
there are no guarantees about upgrade paths but images
|
|
will be consistent and correct with the latest changes.
|
|
</para>
|
|
|
|
<para>
|
|
The simplest form for a PR Service is for it to exist
|
|
for a single host development system that builds the
|
|
package feed (building system).
|
|
For this scenario, you can enable the PR Service by adding
|
|
the following to your <filename>local.conf</filename>
|
|
file in the
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink>:
|
|
<literallayout class='monospaced'>
|
|
PRSERV_HOST = "localhost:0"
|
|
</literallayout>
|
|
Once the service is started, packages will automatically
|
|
get increasing <filename>PR</filename> values and
|
|
BitBake will take care of starting and stopping the server.
|
|
</para>
|
|
|
|
<para>
|
|
If you have a more complex setup where multiple host
|
|
development systems work against a common, shared package
|
|
feed, you have a single PR Service running and it is
|
|
connected to each building system.
|
|
For this scenario, you need to start the PR Service using
|
|
the <filename>bitbake-prserv</filename> command:
|
|
<literallayout class='monospaced'>
|
|
bitbake-prserv ‐‐host <ip> ‐‐port <port> ‐‐start
|
|
</literallayout>
|
|
In addition to hand-starting the service, you need to
|
|
update the <filename>local.conf</filename> file of each
|
|
building system as described earlier so each system
|
|
points to the server and port.
|
|
</para>
|
|
|
|
<para>
|
|
It is also recommended you use Build History, which adds
|
|
some sanity checks to package versions, in conjunction with
|
|
the server that is running the PR Service.
|
|
To enable build history, add the following to each building
|
|
system's <filename>local.conf</filename> file:
|
|
<literallayout class='monospaced'>
|
|
# It is recommended to activate "buildhistory" for testing the PR service
|
|
INHERIT += "buildhistory"
|
|
BUILDHISTORY_COMMIT = "1"
|
|
</literallayout>
|
|
For information on Build History, see the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#maintaining-build-output-quality'>Maintaining Build Output Quality</ulink>"
|
|
section in the Yocto Project Reference Manual.
|
|
</para>
|
|
|
|
<note>
|
|
<para>The OpenEmbedded build system does not maintain
|
|
<filename>PR</filename> information as part of the
|
|
shared state (sstate) packages.
|
|
If you maintain an sstate feed, its expected that either
|
|
all your building systems that contribute to the sstate
|
|
feed use a shared PR Service, or you do not run a PR
|
|
Service on any of your building systems.
|
|
Having some systems use a PR Service while others do
|
|
not leads to obvious problems.</para>
|
|
<para>For more information on shared state, see the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#shared-state-cache'>Shared State Cache</ulink>"
|
|
section in the Yocto Project Reference Manual.</para>
|
|
</note>
|
|
</section>
|
|
|
|
<section id='manually-bumping-pr'>
|
|
<title>Manually Bumping PR</title>
|
|
|
|
<para>
|
|
The alternative to setting up a PR Service is to manually
|
|
bump the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PR'><filename>PR</filename></ulink>
|
|
variable.
|
|
</para>
|
|
|
|
<para>
|
|
If a committed change results in changing the package output,
|
|
then the value of the PR variable needs to be increased
|
|
(or "bumped") as part of that commit.
|
|
For new recipes you should add the <filename>PR</filename>
|
|
variable and set its initial value equal to "r0", which is the default.
|
|
Even though the default value is "r0", the practice of adding it to a new recipe makes
|
|
it harder to forget to bump the variable when you make changes
|
|
to the recipe in future.
|
|
</para>
|
|
|
|
<para>
|
|
If you are sharing a common <filename>.inc</filename> file with multiple recipes,
|
|
you can also use the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-INC_PR'>INC_PR</ulink></filename>
|
|
variable to ensure that
|
|
the recipes sharing the <filename>.inc</filename> file are rebuilt when the
|
|
<filename>.inc</filename> file itself is changed.
|
|
The <filename>.inc</filename> file must set <filename>INC_PR</filename>
|
|
(initially to "r0"), and all recipes referring to it should set <filename>PR</filename>
|
|
to "$(INC_PR).0" initially, incrementing the last number when the recipe is changed.
|
|
If the <filename>.inc</filename> file is changed then its
|
|
<filename>INC_PR</filename> should be incremented.
|
|
</para>
|
|
|
|
<para>
|
|
When upgrading the version of a package, assuming the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PV'>PV</ulink></filename>
|
|
changes, the <filename>PR</filename> variable should be
|
|
reset to "r0" (or "$(INC_PR).0" if you are using
|
|
<filename>INC_PR</filename>).
|
|
</para>
|
|
|
|
<para>
|
|
Usually, version increases occur only to packages.
|
|
However, if for some reason <filename>PV</filename> changes but does not
|
|
increase, you can increase the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PE'>PE</ulink></filename>
|
|
variable (Package Epoch).
|
|
The <filename>PE</filename> variable defaults to "0".
|
|
</para>
|
|
|
|
<para>
|
|
Version numbering strives to follow the
|
|
<ulink url='http://www.debian.org/doc/debian-policy/ch-controlfields.html'>
|
|
Debian Version Field Policy Guidelines</ulink>.
|
|
These guidelines define how versions are compared and what "increasing" a version means.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="usingpoky-configuring-DISTRO_PN_ALIAS">
|
|
<title>Handling a Package Name Alias</title>
|
|
<para>
|
|
Sometimes a package name you are using might exist under an alias or as a similarly named
|
|
package in a different distribution.
|
|
The OpenEmbedded build system implements a <filename>distro_check</filename>
|
|
task that automatically connects to major distributions
|
|
and checks for these situations.
|
|
If the package exists under a different name in a different distribution, you get a
|
|
<filename>distro_check</filename> mismatch.
|
|
You can resolve this problem by defining a per-distro recipe name alias using the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_PN_ALIAS'>DISTRO_PN_ALIAS</ulink></filename>
|
|
variable.
|
|
</para>
|
|
|
|
<para>
|
|
Following is an example that shows how you specify the <filename>DISTRO_PN_ALIAS</filename>
|
|
variable:
|
|
<literallayout class='monospaced'>
|
|
DISTRO_PN_ALIAS_pn-PACKAGENAME = "distro1=package_name_alias1 \
|
|
distro2=package_name_alias2 \
|
|
distro3=package_name_alias3 \
|
|
..."
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
If you have more than one distribution alias, separate them with a space.
|
|
Note that the build system currently automatically checks the
|
|
Fedora, OpenSUSE, Debian, Ubuntu,
|
|
and Mandriva distributions for source package recipes without having to specify them
|
|
using the <filename>DISTRO_PN_ALIAS</filename> variable.
|
|
For example, the following command generates a report that lists the Linux distributions
|
|
that include the sources for each of the recipes.
|
|
<literallayout class='monospaced'>
|
|
$ bitbake world -f -c distro_check
|
|
</literallayout>
|
|
The results are stored in the <filename>build/tmp/log/distro_check-${DATETIME}.results</filename>
|
|
file found in the
|
|
<link linkend='source-directory'>Source Directory</link>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='handling-optional-module-packaging'>
|
|
<title>Handling Optional Module Packaging</title>
|
|
|
|
<para>
|
|
Many pieces of software split functionality into optional
|
|
modules (or plug-ins) and the plug-ins that are built
|
|
might depend on configuration options.
|
|
To avoid having to duplicate the logic that determines what
|
|
modules are available in your recipe or to avoid having
|
|
to package each module by hand, the OpenEmbedded build system
|
|
provides functionality to handle module packaging dynamically.
|
|
</para>
|
|
|
|
<para>
|
|
To handle optional module packaging, you need to do two things:
|
|
<itemizedlist>
|
|
<listitem><para>Ensure the module packaging is actually
|
|
done</para></listitem>
|
|
<listitem><para>Ensure that any dependencies on optional
|
|
modules from other recipes are satisfied by your recipe
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<section id='making-sure-the-packaging-is-done'>
|
|
<title>Making Sure the Packaging is Done</title>
|
|
|
|
<para>
|
|
To ensure the module packaging actually gets done, you use
|
|
the <filename>do_split_packages</filename> function within
|
|
the <filename>populate_packages</filename> Python function
|
|
in your recipe.
|
|
The <filename>do_split_packages</filename> function
|
|
searches for a pattern of files or directories under a
|
|
specified path and creates a package for each one it finds
|
|
by appending to the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES'><filename>PACKAGES</filename></ulink>
|
|
variable and setting the appropriate values for
|
|
<filename>FILES_packagename</filename>,
|
|
<filename>RDEPENDS_packagename</filename>,
|
|
<filename>DESCRIPTION_packagename</filename>, and so forth.
|
|
Here is an example from the <filename>lighttpd</filename>
|
|
recipe:
|
|
<literallayout class='monospaced'>
|
|
python populate_packages_prepend () {
|
|
lighttpd_libdir = d.expand('${libdir}')
|
|
do_split_packages(d, lighttpd_libdir, '^mod_(.*)\.so$',
|
|
'lighttpd-module-%s', 'Lighttpd module for %s',
|
|
extra_depends='')
|
|
}
|
|
</literallayout>
|
|
The previous example specifies a number of things in the
|
|
call to <filename>do_split_packages</filename>.
|
|
<itemizedlist>
|
|
<listitem><para>A directory within the files installed
|
|
by your recipe through <filename>do_install</filename>
|
|
in which to search.</para></listitem>
|
|
<listitem><para>A regular expression to match module
|
|
files in that directory.
|
|
In the example, note the parentheses () that mark
|
|
the part of the expression from which the module
|
|
name should be derived.</para></listitem>
|
|
<listitem><para>A pattern to use for the package names.
|
|
</para></listitem>
|
|
<listitem><para>A description for each package.
|
|
</para></listitem>
|
|
<listitem><para>An empty string for
|
|
<filename>extra_depends</filename>, which disables
|
|
the default dependency on the main
|
|
<filename>lighttpd</filename> package.
|
|
Thus, if a file in <filename>${libdir}</filename>
|
|
called <filename>mod_alias.so</filename> is found,
|
|
a package called <filename>lighttpd-module-alias</filename>
|
|
is created for it and the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DESCRIPTION'><filename>DESCRIPTION</filename></ulink>
|
|
is set to "Lighttpd module for alias".</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Often, packaging modules is as simple as the previous
|
|
example.
|
|
However, more advanced options exist that you can use
|
|
within <filename>do_split_packages</filename> to modify its
|
|
behavior.
|
|
And, if you need to, you can add more logic by specifying
|
|
a hook function that is called for each package.
|
|
It is also perfectly acceptable to call
|
|
<filename>do_split_packages</filename> multiple times if
|
|
you have more than one set of modules to package.
|
|
</para>
|
|
|
|
<para>
|
|
For more examples that show how to use
|
|
<filename>do_split_packages</filename>, see the
|
|
<filename>connman.inc</filename> file in the
|
|
<filename>meta/recipes-connectivity/connman/</filename>
|
|
directory of the <filename>poky</filename>
|
|
<link linkend='yocto-project-repositories'>source repository</link>.
|
|
You can also find examples in
|
|
<filename>meta/classes/kernel.bbclass</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
Following is a reference that shows
|
|
<filename>do_split_packages</filename> mandatory and
|
|
optional arguments:
|
|
<literallayout class='monospaced'>
|
|
Mandatory arguments
|
|
|
|
root
|
|
The path in which to search
|
|
file_regex
|
|
Regular expression to match searched files.
|
|
Use parentheses () to mark the part of this
|
|
expression that should be used to derive the
|
|
module name (to be substituted where %s is
|
|
used in other function arguments as noted below)
|
|
output_pattern
|
|
Pattern to use for the package names. Must
|
|
include %s.
|
|
description
|
|
Description to set for each package. Must
|
|
include %s.
|
|
|
|
Optional arguments
|
|
|
|
postinst
|
|
Postinstall script to use for all packages
|
|
(as a string)
|
|
recursive
|
|
True to perform a recursive search - default
|
|
False
|
|
hook
|
|
A hook function to be called for every match.
|
|
The function will be called with the following
|
|
arguments (in the order listed):
|
|
|
|
f
|
|
Full path to the file/directory match
|
|
pkg
|
|
The package name
|
|
file_regex
|
|
As above
|
|
output_pattern
|
|
As above
|
|
modulename
|
|
The module name derived using file_regex
|
|
|
|
extra_depends
|
|
Extra runtime dependencies (RDEPENDS) to be
|
|
set for all packages. The default value of None
|
|
causes a dependency on the main package
|
|
(${PN}) - if you do not want this, pass empty
|
|
string '' for this parameter.
|
|
aux_files_pattern
|
|
Extra item(s) to be added to FILES for each
|
|
package. Can be a single string item or a list
|
|
of strings for multiple items. Must include %s.
|
|
postrm
|
|
postrm script to use for all packages (as a
|
|
string)
|
|
allow_dirs
|
|
True to allow directories to be matched -
|
|
default False
|
|
prepend
|
|
If True, prepend created packages to PACKAGES
|
|
instead of the default False which appends them
|
|
match_path
|
|
match file_regex on the whole relative path to
|
|
the root rather than just the file name
|
|
aux_files_pattern_verbatim
|
|
Extra item(s) to be added to FILES for each
|
|
package, using the actual derived module name
|
|
rather than converting it to something legal
|
|
for a package name. Can be a single string item
|
|
or a list of strings for multiple items. Must
|
|
include %s.
|
|
allow_links
|
|
True to allow symlinks to be matched - default
|
|
False
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='satisfying-dependencies'>
|
|
<title>Satisfying Dependencies</title>
|
|
|
|
<para>
|
|
The second part for handling optional module packaging
|
|
is to ensure that any dependencies on optional modules
|
|
from other recipes are satisfied by your recipe.
|
|
You can be sure these dependencies are satisfied by
|
|
using the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGES_DYNAMIC'><filename>PACKAGES_DYNAMIC</filename></ulink> variable.
|
|
Here is an example that continues with the
|
|
<filename>lighttpd</filename> recipe shown earlier:
|
|
<literallayout class='monospaced'>
|
|
PACKAGES_DYNAMIC = "lighttpd-module-.*"
|
|
</literallayout>
|
|
The name specified in the regular expression can of
|
|
course be anything.
|
|
In this example, it is <filename>lighttpd-module-</filename>
|
|
and is specified as the prefix to ensure that any
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-RDEPENDS'><filename>RDEPENDS</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-RRECOMMENDS'><filename>RRECOMMENDS</filename></ulink>
|
|
on a package name starting with the prefix are satisfied
|
|
during build time.
|
|
If you are using <filename>do_split_packages</filename>
|
|
as described in the previous section, the value you put in
|
|
<filename>PACKAGES_DYNAMIC</filename> should correspond to
|
|
the name pattern specified in the call to
|
|
<filename>do_split_packages</filename>.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='using-runtime-package-management'>
|
|
<title>Using Runtime Package Management</title>
|
|
|
|
<para>
|
|
During a build, BitBake always transforms a recipe into one or
|
|
more packages.
|
|
For example, BitBake takes the <filename>bash</filename> recipe
|
|
and currently produces the <filename>bash-dbg</filename>,
|
|
<filename>bash-staticdev</filename>,
|
|
<filename>bash-dev</filename>, <filename>bash-doc</filename>,
|
|
<filename>bash-locale</filename>, and
|
|
<filename>bash</filename> packages.
|
|
Not all generated packages are included in an image.
|
|
</para>
|
|
|
|
<para>
|
|
In several situations, you might need to update, add, remove,
|
|
or query the packages on a target device at runtime
|
|
(i.e. without having to generate a new image).
|
|
Examples of such situations include:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
You want to provide in-the-field updates to deployed
|
|
devices (e.g. security updates).
|
|
</para></listitem>
|
|
<listitem><para>
|
|
You want to have a fast turn-around development cycle
|
|
for one or more applications that run on your device.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
You want to temporarily install the "debug" packages
|
|
of various applications on your device so that
|
|
debugging can be greatly improved by allowing
|
|
access to symbols and source debugging.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
You want to deploy a more minimal package selection of
|
|
your device but allow in-the-field updates to add a
|
|
larger selection for customization.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
In all these situations, you have something similar to a more
|
|
traditional Linux distribution in that in-field devices
|
|
are able to receive pre-compiled packages from a server for
|
|
installation or update.
|
|
Being able to install these packages on a running,
|
|
in-field device is what is termed "runtime package
|
|
management".
|
|
</para>
|
|
|
|
<para>
|
|
In order to use runtime package management, you
|
|
need a host/server machine that serves up the pre-compiled
|
|
packages plus the required metadata.
|
|
You also need package manipulation tools on the target.
|
|
The build machine is a likely candidate to act as the server.
|
|
However, that machine does not necessarily have to be the
|
|
package server.
|
|
The build machine could push its artifacts to another machine
|
|
that acts as the server (e.g. Internet-facing).
|
|
</para>
|
|
|
|
<para>
|
|
A simple build that targets just one device produces
|
|
more than one package database.
|
|
In other words, the packages produced by a build are separated
|
|
out into a couple of different package groupings based on
|
|
criteria such as the target's CPU architecture, the target
|
|
board, or the C library used on the target.
|
|
For example, a build targeting the <filename>qemuarm</filename>
|
|
device produces the following three package databases:
|
|
<filename>all</filename>, <filename>armv5te</filename>, and
|
|
<filename>qemuarm</filename>.
|
|
If you wanted your <filename>qemuarm</filename> device to be
|
|
aware of all the packages that were available to it,
|
|
you would need to point it to each of these databases
|
|
individually.
|
|
In a similar way, a traditional Linux distribution usually is
|
|
configured to be aware of a number of software repositories
|
|
from which it retrieves packages.
|
|
</para>
|
|
|
|
<para>
|
|
Using runtime package management is completely optional and
|
|
not required for a successful build or deployment in any
|
|
way.
|
|
But if you want to make use of runtime package management,
|
|
you need to do a couple things above and beyond the basics.
|
|
The remainder of this section describes what you need to do.
|
|
</para>
|
|
|
|
<section id='runtime-package-management-build'>
|
|
<title>Build Considerations</title>
|
|
|
|
<para>
|
|
This section describes build considerations that you need
|
|
to be aware of in order to provide support for runtime
|
|
package management.
|
|
</para>
|
|
|
|
<para>
|
|
When BitBake generates packages it needs to know
|
|
what format(s) to use.
|
|
In your configuration, you use the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGE_CLASSES'><filename>PACKAGE_CLASSES</filename></ulink>
|
|
variable to specify the format.
|
|
<note>
|
|
You can choose to have more than one format but you must
|
|
provide at least one.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
If you would like your image to start off with a basic
|
|
package database of the packages in your current build
|
|
as well as have the relevant tools available on the
|
|
target for runtime package management, you can include
|
|
"package-management" in the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></ulink>
|
|
variable.
|
|
Including "package-management" in this
|
|
configuration variable ensures that when the image
|
|
is assembled for your target, the image includes
|
|
the currently-known package databases as well as
|
|
the target-specific tools required for runtime
|
|
package management to be performed on the target.
|
|
However, this is not strictly necessary.
|
|
You could start your image off without any databases
|
|
but only include the required on-target package
|
|
tool(s).
|
|
As an example, you could include "opkg" in your
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'><filename>IMAGE_INSTALL</filename></ulink>
|
|
variable if you are using the IPK package format.
|
|
You can then initialize your target's package database(s)
|
|
later once your image is up and running.
|
|
</para>
|
|
|
|
<para>
|
|
Whenever you perform any sort of build step that can
|
|
potentially generate a package or modify an existing
|
|
package, it is always a good idea to re-generate the
|
|
package index with:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake package-index
|
|
</literallayout>
|
|
Realize that it is not sufficient to simply do the
|
|
following:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake <some-package> package-index
|
|
</literallayout>
|
|
This is because BitBake does not properly schedule the
|
|
<filename>package-index</filename> target fully after any
|
|
other target has completed.
|
|
Thus, be sure to run the package update step separately.
|
|
</para>
|
|
|
|
<para>
|
|
As described below in the
|
|
"<link linkend='runtime-package-management-target-ipk'>Using IPK</link>"
|
|
section, if you are using IPK as your package format, you
|
|
can make use of the
|
|
<filename>distro-feed-configs</filename> recipe provided
|
|
by <filename>meta-oe</filename> in order to configure your
|
|
target to use your IPK databases.
|
|
</para>
|
|
|
|
<para>
|
|
When your build is complete, your packages reside in the
|
|
<filename>${TMPDIR}/deploy/<package-format></filename>
|
|
directory.
|
|
For example, if <filename>${TMPDIR}</filename>
|
|
is <filename>tmp</filename> and your selected package type
|
|
is IPK, then your IPK packages are available in
|
|
<filename>tmp/deploy/ipk</filename>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='runtime-package-management-server'>
|
|
<title>Host or Server Machine Setup</title>
|
|
|
|
<para>
|
|
Typically, packages are served from a server using
|
|
HTTP.
|
|
However, other protocols are possible.
|
|
If you want to use HTTP, then setup and configure a
|
|
web server, such as Apache 2 or lighttpd, on the machine
|
|
serving the packages.
|
|
</para>
|
|
|
|
<para>
|
|
As previously mentioned, the build machine can act as the
|
|
package server.
|
|
In the following sections that describe server machine
|
|
setups, the build machine is assumed to also be the server.
|
|
</para>
|
|
|
|
<section id='package-server-apache'>
|
|
<title>Serving Packages via Apache 2</title>
|
|
|
|
<para>
|
|
This example assumes you are using the Apache 2
|
|
server:
|
|
<orderedlist>
|
|
<listitem><para>
|
|
Add the directory to your Apache
|
|
configuration, which you can find at
|
|
<filename>/etc/httpd/conf/httpd.conf</filename>.
|
|
Use commands similar to these on the
|
|
development system.
|
|
These example commands assume a top-level
|
|
<link linkend='source-directory'>Source Directory</link>
|
|
named <filename>poky</filename> in your home
|
|
directory.
|
|
The example also assumes an RPM package type.
|
|
If you are using a different package type, such
|
|
as IPK, use "ipk" in the pathnames:
|
|
<literallayout class='monospaced'>
|
|
<VirtualHost *:80>
|
|
....
|
|
Alias /rpm ~/poky/build/tmp/deploy/rpm
|
|
<Directory "~/poky/build/tmp/deploy/rpm">
|
|
Options +Indexes
|
|
</Directory>
|
|
</VirtualHost>
|
|
</literallayout></para></listitem>
|
|
<listitem><para>
|
|
Reload the Apache configuration as described
|
|
in this step.
|
|
For all commands, be sure you have root
|
|
privileges.
|
|
</para>
|
|
|
|
<para>
|
|
If your development system is using Fedora or
|
|
CentOS, use the following:
|
|
<literallayout class='monospaced'>
|
|
# service httpd reload
|
|
</literallayout>
|
|
For Ubuntu and Debian, use the following:
|
|
<literallayout class='monospaced'>
|
|
# /etc/init.d/apache2 reload
|
|
</literallayout>
|
|
For OpenSUSE, use the following:
|
|
<literallayout class='monospaced'>
|
|
# /etc/init.d/apache2 reload
|
|
</literallayout></para></listitem>
|
|
<listitem><para>
|
|
If you are using Security-Enhanced Linux
|
|
(SELinux), you need to label the files as
|
|
being accessible through Apache.
|
|
Use the following command from the development
|
|
host.
|
|
This example assumes RPM package types:
|
|
<literallayout class='monospaced'>
|
|
# chcon -R -h -t httpd_sys_content_t tmp/deploy/rpm
|
|
</literallayout></para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='package-server-lighttpd'>
|
|
<title>Serving Packages via lighttpd</title>
|
|
|
|
<para>
|
|
If you are using lighttpd, all you need
|
|
to do is to provide a link from your
|
|
<filename>${TMPDIR}/deploy/<package-format></filename>
|
|
directory to lighttpd's document-root.
|
|
You can determine the specifics of your lighttpd
|
|
installation by looking through its configuration file,
|
|
which is usually found at:
|
|
<filename>/etc/lighttpd/lighttpd.conf</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
For example, if you are using IPK, lighttpd's
|
|
document-root is set to
|
|
<filename>/var/www/lighttpd</filename>, and you had
|
|
packages for a target named "BOARD",
|
|
then you might create a link from your build location
|
|
to lighttpd's document-root as follows:
|
|
<literallayout class='monospaced'>
|
|
# ln -s $(PWD)/tmp/deploy/ipk /var/www/lighttpd/BOARD-dir
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
At this point, you need to start the lighttpd server.
|
|
The method used to start the server varies by
|
|
distribution.
|
|
However, one basic method that starts it by hand is:
|
|
<literallayout class='monospaced'>
|
|
# lighttpd -f /etc/lighttpd/lighttpd.conf
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='runtime-package-management-target'>
|
|
<title>Target Setup</title>
|
|
|
|
<para>
|
|
Setting up the target differs depending on the
|
|
package management system.
|
|
This section provides information for RPM and IPK.
|
|
</para>
|
|
|
|
<section id='runtime-package-management-target-rpm'>
|
|
<title>Using RPM</title>
|
|
|
|
<para>
|
|
The application for performing runtime package
|
|
management of RPM packages on the target is called
|
|
<filename>smart</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
On the target machine, you need to inform
|
|
<filename>smart</filename> of every package database
|
|
you want to use.
|
|
As an example, suppose your target device can use the
|
|
following three package databases from a server named
|
|
<filename>server.name</filename>:
|
|
<filename>all</filename>, <filename>i586</filename>,
|
|
and <filename>qemux86</filename>.
|
|
Given this example, issue the following commands on the
|
|
target:
|
|
<literallayout class='monospaced'>
|
|
# smart channel --add all type=rpm-md baseurl=http://server.name/rpm/all
|
|
# smart channel --add i585 type=rpm-md baseurl=http://server.name/rpm/i586
|
|
# smart channel --add qemux86 type=rpm-md baseurl=http://server.name/rpm/qemux86
|
|
</literallayout>
|
|
Also from the target machine, fetch the repository
|
|
information using this command:
|
|
<literallayout class='monospaced'>
|
|
# smart update
|
|
</literallayout>
|
|
You can now use the <filename>smart query</filename>
|
|
and <filename>smart install</filename> commands to
|
|
find and install packages from the repositories.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='runtime-package-management-target-ipk'>
|
|
<title>Using IPK</title>
|
|
|
|
<para>
|
|
The application for performing runtime package
|
|
management of IPK packages on the target is called
|
|
<filename>opkg</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
In order to inform <filename>opkg</filename> of the
|
|
package databases you want to use, simply create one
|
|
or more <filename>*.conf</filename> files in the
|
|
<filename>/etc/opkg</filename> directory on the target.
|
|
The <filename>opkg</filename> application uses them
|
|
to find its available package databases.
|
|
As an example, suppose you configured your HTTP server
|
|
on your machine named
|
|
<filename>www.mysite.com</filename> to serve files
|
|
from a <filename>BOARD-dir</filename> directory under
|
|
its document-root.
|
|
In this case, you might create a configuration
|
|
file on the target called
|
|
<filename>/etc/opkg/base-feeds.conf</filename> that
|
|
contains:
|
|
<literallayout class='monospaced'>
|
|
src/gz all http://www.mysite.com/BOARD-dir/all
|
|
src/gz armv7a http://www.mysite.com/BOARD-dir/armv7a
|
|
src/gz beagleboard http://www.mysite.com/BOARD-dir/beagleboard
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
As a way of making it easier to generate and make
|
|
these IPK configuration files available on your
|
|
target, the <filename>meta-oe</filename> layer
|
|
provides a recipe called
|
|
<filename>distro-feed-configs</filename>, which
|
|
provides a package by the same name.
|
|
When you include this package into your image, it will
|
|
automatically generate and include a set of
|
|
<filename>*.conf</filename> files in the image's
|
|
<filename>/etc/opkg</filename> directory that will
|
|
provide your target's <filename>opkg</filename>
|
|
tool with any and all package databases your build will
|
|
generate.
|
|
The only catch is that this recipe cannot possibly
|
|
imagine your server's DNS name/IP address.
|
|
Consequently, somewhere in your configuration you need
|
|
to set a variable called
|
|
<filename>DISTRO_FEED_URI</filename> to point
|
|
to your server and the location within the
|
|
document-root that contains the databases.
|
|
For example: if you are serving your packages over HTTP,
|
|
your server's IP address is 192.168.7.1, and your
|
|
databases are located in a directory called
|
|
<filename>BOARD-dir</filename> underneath your HTTP
|
|
server's document-root, you need to set
|
|
<filename>DISTRO_FEED_URI</filename> to
|
|
<filename>http://192.168.7.1/BOARD-dir</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
On the target machine, fetch (or refresh) the
|
|
repository information using this command:
|
|
<literallayout class='monospaced'>
|
|
# opkg update
|
|
</literallayout>
|
|
You can now use the <filename>opkg list</filename> and
|
|
<filename>opkg install</filename> commands to find and
|
|
install packages from the repositories.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='testing-packages-with-ptest'>
|
|
<title>Testing Packages With ptest</title>
|
|
|
|
<para>
|
|
A Package Test (ptest) runs tests against packages built
|
|
by the OpenEmbedded build system on the target machine.
|
|
A ptest contains at least two items: the actual test, and
|
|
a shell script (<filename>run-ptest</filename>) that starts
|
|
the test.
|
|
The shell script that starts the test must not contain
|
|
the actual test, the script only starts it.
|
|
On the other hand, the test can be anything from a simple
|
|
shell script that runs a binary and checks the output to
|
|
an elaborate system of test binaries and data files.
|
|
</para>
|
|
|
|
<para>
|
|
The test generates output in the format used by
|
|
Automake:
|
|
<literallayout class='monospaced'>
|
|
<result>: <testname>
|
|
</literallayout>
|
|
where the result can be <filename>PASS</filename>,
|
|
<filename>FAIL</filename>, or <filename>SKIP</filename>,
|
|
and the testname can be any identifying string.
|
|
</para>
|
|
|
|
<note>
|
|
With this release of the Yocto Project, three recipes exist
|
|
that are "ptest-enabled": <filename>bash</filename>,
|
|
<filename>glib-2.0</filename>, and
|
|
<filename>dbus</filename>.
|
|
These three recipes are Autotool-enabled.
|
|
</note>
|
|
|
|
<section id='adding-ptest-to-your-build'>
|
|
<title>Adding ptest to Your Build</title>
|
|
|
|
<para>
|
|
To add package testing to your build, add the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGE_FEATURES'><filename>EXTRA_IMAGE_FEATURES</filename></ulink>
|
|
variables to your <filename>local.conf</filename> file,
|
|
which is found in the
|
|
<link linkend='build-directory'>Build Directory</link>:
|
|
<literallayout class='monospaced'>
|
|
DISTRO_FEATURES_append = " ptest"
|
|
EXTRA_IMAGE_FEATURES += "ptest-pkgs"
|
|
</literallayout>
|
|
Once your build is complete, the ptest files are installed
|
|
into the <filename>/usr/lib/<package>/ptest</filename>
|
|
directory within the image, where
|
|
<filename><package></filename> is the name of the
|
|
package.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='running-ptest'>
|
|
<title>Running ptest</title>
|
|
|
|
<para>
|
|
The <filename>ptest-runner</filename> package installs a
|
|
shell script that loops through all installed ptest test
|
|
suites and runs them in sequence.
|
|
Consequently, you might want to add this package to
|
|
your image.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='getting-your-package-ready'>
|
|
<title>Getting Your Package Ready</title>
|
|
|
|
<para>
|
|
In order to enable a recipe to run installed ptests
|
|
on target hardware,
|
|
you need to prepare the recipes that build the packages
|
|
you want to test.
|
|
Here is what you have to do for each recipe:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Be sure the recipe
|
|
inherits ptest:</emphasis>
|
|
Include the following line in each recipe:
|
|
<literallayout class='monospaced'>
|
|
inherit ptest
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Create <filename>run-ptest</filename>:</emphasis>
|
|
This script starts your test.
|
|
Locate the script where you will refer to it
|
|
using
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>.
|
|
Here is an example that starts a test for
|
|
<filename>dbus</filename>:
|
|
<literallayout class='monospaced'>
|
|
#!/bin/sh
|
|
cd test
|
|
make -k runtest-TESTS
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Ensure dependencies are
|
|
met:</emphasis>
|
|
If the test adds build or runtime dependencies
|
|
that normally do not exist for the package
|
|
(such as requiring "make" to run the test suite),
|
|
use the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DEPENDS'><filename>DEPENDS</filename></ulink>
|
|
and
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-RDEPENDS'><filename>RDEPENDS</filename></ulink>
|
|
variables in your recipe in order for the package
|
|
to meet the dependencies.
|
|
Here is an example where the package has a runtime
|
|
dependency on "make":
|
|
<literallayout class='monospaced'>
|
|
RDEPENDS_${PN}-ptest += "make"
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Add a function to build the
|
|
test suite:</emphasis>
|
|
Not many packages support cross-compilation of
|
|
their test suites.
|
|
Consequently, you usually need to add a
|
|
cross-compilation function to the package.
|
|
</para>
|
|
<para>Many packages based on Automake compile and
|
|
run the test suite by using a single command
|
|
such as <filename>make check</filename>.
|
|
However, the native <filename>make check</filename>
|
|
builds and runs on the same computer, while
|
|
cross-compiling requires that the package is built
|
|
on the host but executed on the target.
|
|
The built version of Automake that ships with the
|
|
Yocto Project includes a patch that separates
|
|
building and execution.
|
|
Consequently, packages that use the unaltered,
|
|
patched version of <filename>make check</filename>
|
|
automatically cross-compiles.</para>
|
|
<para>However, you still must add a
|
|
<filename>do_compile_ptest</filename> function to
|
|
build the test suite.
|
|
Add a function similar to the following to your
|
|
recipe:
|
|
<literallayout class='monospaced'>
|
|
do_compile_ptest() {
|
|
oe_runmake buildtest-TESTS
|
|
}
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Ensure special configurations
|
|
are set:</emphasis>
|
|
If the package requires special configurations
|
|
prior to compiling the test code, you must
|
|
insert a <filename>do_configure_ptest</filename>
|
|
function into the recipe.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Install the test
|
|
suite:</emphasis>
|
|
The <filename>ptest.bbclass</filename> class
|
|
automatically copies the file
|
|
<filename>run-ptest</filename> to the target and
|
|
then runs make <filename>install-ptest</filename>
|
|
to run the tests.
|
|
If this is not enough, you need to create a
|
|
<filename>do_install_ptest</filename> function and
|
|
make sure it gets called after the
|
|
"make install-ptest" completes.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="building-software-from-an-external-source">
|
|
<title>Building Software from an External Source</title>
|
|
|
|
<para>
|
|
By default, the OpenEmbedded build system uses the
|
|
<link linkend='build-directory'>Build Directory</link> to
|
|
build source code.
|
|
The build process involves fetching the source files, unpacking
|
|
them, and then patching them if necessary before the build takes
|
|
place.
|
|
</para>
|
|
|
|
<para>
|
|
Situations exist where you might want to build software from source
|
|
files that are external to and thus outside of the
|
|
OpenEmbedded build system.
|
|
For example, suppose you have a project that includes a new BSP with
|
|
a heavily customized kernel.
|
|
And, you want to minimize exposing the build system to the
|
|
development team so that they can focus on their project and
|
|
maintain everyone's workflow as much as possible.
|
|
In this case, you want a kernel source directory on the development
|
|
machine where the development occurs.
|
|
You want the recipe's
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
variable to point to the external directory and use it as is, not
|
|
copy it.
|
|
</para>
|
|
|
|
<para>
|
|
To build from software that comes from an external source, all you
|
|
need to do is inherit
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-externalsrc'><filename>externalsrc.bbclass</filename></ulink>
|
|
and then set the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTERNALSRC'><filename>EXTERNALSRC</filename></ulink>
|
|
variable to point to your external source code.
|
|
Here are the statements to put in your
|
|
<filename>local.conf</filename> file:
|
|
<literallayout class='monospaced'>
|
|
INHERIT += "externalsrc"
|
|
EXTERNALSRC_pn-myrecipe = "/some/path/to/your/source/tree"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
By default, <filename>externalsrc.bbclass</filename> builds
|
|
the source code in a directory separate from the external source
|
|
directory as specified by
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTERNALSRC'><filename>EXTERNALSRC</filename></ulink>.
|
|
If you need to have the source built in the same directory in
|
|
which it resides, or some other nominated directory, you can set
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTERNALSRC_BUILD'><filename>EXTERNALSRC_BUILD</filename></ulink>
|
|
to point to that directory:
|
|
<literallayout class='monospaced'>
|
|
EXTERNALSRC_BUILD_pn-myrecipe = "/path/to/my/source/tree"
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="selecting-an-initialization-manager">
|
|
<title>Selecting an Initialization Manager</title>
|
|
|
|
<para>
|
|
By default, the Yocto Project uses
|
|
<filename>SysVinit</filename> as the initialization manager.
|
|
However, support also exists for <filename>systemd</filename>,
|
|
which is a full replacement for <filename>init</filename> with
|
|
parallel starting of services, reduced shell overhead and other
|
|
features that are used by many distributions.
|
|
</para>
|
|
|
|
<para>
|
|
If you want to use <filename>sysvinit</filename>, you do
|
|
not have to do anything.
|
|
But, if you want to use <filename>systemd</filename>, you must
|
|
take some steps as described in the following sections.
|
|
</para>
|
|
|
|
<!--
|
|
<note>
|
|
It is recommended that you create your own distribution configuration
|
|
file to hold these settings instead of using your
|
|
<filename>local.conf</filename> file.
|
|
For information on creating your own distribution, see the
|
|
"<link linkend='creating-your-own-distribution'>Creating Your Own Distribution</link>"
|
|
section.
|
|
</note>
|
|
-->
|
|
|
|
<section id='using-systemd-exclusively'>
|
|
<title>Using systemd Exclusively</title>
|
|
|
|
<para>
|
|
Set the following variables in your distribution configuration
|
|
file as follows:
|
|
<literallayout class='monospaced'>
|
|
DISTRO_FEATURES_append = " systemd"
|
|
VIRTUAL-RUNTIME_init_manager = "systemd"
|
|
</literallayout>
|
|
You can also prevent the <filename>sysvinit</filename>
|
|
distribution feature from
|
|
being automatically enabled as follows:
|
|
<literallayout class='monospaced'>
|
|
DISTRO_FEATURES_BACKFILL_CONSIDERED = "sysvinit"
|
|
</literallayout>
|
|
Doing so removes any redundant <filename>sysvinit</filename>
|
|
scripts.
|
|
</para>
|
|
|
|
<para>
|
|
For information on the backfill variable, see
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES_BACKFILL_CONSIDERED'><filename>DISTRO_FEATURES_BACKFILL_CONSIDERED</filename></ulink>
|
|
in the Yocto Project Reference Manual.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='using-systemd-for-the-main-image-and-using-sysvinit-for-the-rescue-image'>
|
|
<title>Using systemd for the Main Image and Using SysVinit for the Rescue Image</title>
|
|
|
|
<para>
|
|
Set the following variables in your distribution configuration
|
|
file as follows:
|
|
<literallayout class='monospaced'>
|
|
DISTRO_FEATURES_append = " systemd"
|
|
VIRTUAL-RUNTIME_init_manager = "systemd"
|
|
</literallayout>
|
|
Doing so causes your main image to use the
|
|
<filename>packagegroup-core-boot.bb</filename> recipe and
|
|
<filename>systemd</filename>.
|
|
The rescue/minimal image cannot use this package group.
|
|
However, it can install <filename>sysvinit</filename>
|
|
and the appropriate packages will have support for both
|
|
<filename>systemd</filename> and <filename>sysvinit</filename>.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='excluding-recipes-from-the-build'>
|
|
<title>Excluding Recipes From the Build</title>
|
|
|
|
<para>
|
|
You might find that there are groups of recipes or append files
|
|
that you want to filter out of the build process.
|
|
Usually, this is not necessary.
|
|
However, on rare occasions where you might want to use a
|
|
layer but exclude parts that are causing problems, such
|
|
as introducing a different version of a recipe, you can
|
|
use
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBMASK'><filename>BBMASK</filename></ulink>
|
|
to exclude the recipe.
|
|
</para>
|
|
|
|
<para>
|
|
It is possible to filter or mask out <filename>.bb</filename> and
|
|
<filename>.bbappend</filename> files.
|
|
You can do this by providing an expression with the
|
|
<filename>BBMASK</filename> variable.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
BBMASK = "/meta-mymachine/recipes-maybe/"
|
|
</literallayout>
|
|
Here, all <filename>.bb</filename> and
|
|
<filename>.bbappend</filename> files in the directory that match
|
|
the expression are ignored during the build process.
|
|
</para>
|
|
|
|
<note>
|
|
The value you provide is passed to Python's regular expression
|
|
compiler.
|
|
The expression is compared against the full paths to the files.
|
|
For complete syntax information, see Python's documentation at
|
|
<ulink url='http://docs.python.org/release/2.3/lib/re-syntax.html'></ulink>.
|
|
</note>
|
|
</section>
|
|
|
|
<section id="platdev-appdev-srcrev">
|
|
<title>Using an External SCM</title>
|
|
|
|
<para>
|
|
If you're working on a recipe that pulls from an external Source Code Manager (SCM), it
|
|
is possible to have the OpenEmbedded build system notice new recipe changes added to the
|
|
SCM and then build the resulting package that depends on the new recipes by using the latest
|
|
versions.
|
|
This only works for SCMs from which it is possible to get a sensible revision number for changes.
|
|
Currently, you can do this with Apache Subversion (SVN), Git, and Bazaar (BZR) repositories.
|
|
</para>
|
|
|
|
<para>
|
|
To enable this behavior, simply add the following to the <filename>local.conf</filename>
|
|
configuration file found in the
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink>:
|
|
<literallayout class='monospaced'>
|
|
SRCREV_pn-<PN> = "${AUTOREV}"
|
|
</literallayout>
|
|
where <ulink url='&YOCTO_DOCS_REF_URL;#var-PN'><filename>PN</filename></ulink>
|
|
is the name of the recipe for which you want to enable automatic source
|
|
revision updating.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='creating-a-read-only-root-filesystem'>
|
|
<title>Creating a Read-Only Root Filesystem</title>
|
|
|
|
<para>
|
|
Suppose, for security reasons, you need to disable
|
|
your target device's root filesystem's write permissions
|
|
(i.e. you need a read-only root filesystem).
|
|
Or, perhaps you are running the device's operating system
|
|
from a read-only storage device.
|
|
For either case, you can customize your image for
|
|
that behavior.
|
|
</para>
|
|
|
|
<note>
|
|
Supporting a read-only root filesystem requires that the system and
|
|
applications do not try to write to the root filesystem.
|
|
You must configure all parts of the target system to write
|
|
elsewhere, or to gracefully fail in the event of failing to
|
|
write to the root filesystem.
|
|
</note>
|
|
|
|
<section id='creating-the-root-filesystem'>
|
|
<title>Creating the Root Filesystem</title>
|
|
|
|
<para>
|
|
To create the read-only root filesystem, simply add the
|
|
<filename>read-only-rootfs</filename> feature to your image.
|
|
Using either of the following statements in your
|
|
image recipe or from within the
|
|
<filename>local.conf</filename> file found in the
|
|
<link linkend='build-directory'>Build Directory</link>
|
|
causes the build system to create a read-only root filesystem:
|
|
<literallayout class='monospaced'>
|
|
IMAGE_FEATURES = "read-only-rootfs"
|
|
</literallayout>
|
|
or
|
|
<literallayout class='monospaced'>
|
|
EXTRA_IMAGE_FEATURES = "read-only-rootfs"
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
For more information on how to use these variables, see the
|
|
"<link linkend='usingpoky-extend-customimage-imagefeatures'>Customizing Images Using Custom <filename>IMAGE_FEATURES</filename> and <filename>EXTRA_IMAGE_FEATURES</filename></link>"
|
|
section.
|
|
For information on the variables, see
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></ulink>
|
|
and <ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGE_FEATURES'><filename>EXTRA_IMAGE_FEATURES</filename></ulink>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='post-installation-scripts'>
|
|
<title>Post-Installation Scripts</title>
|
|
|
|
<para>
|
|
It is very important that you make sure all
|
|
post-Installation (<filename>pkg_postinst</filename>) scripts
|
|
for packages that are installed into the image can be run
|
|
at the time when the root filesystem is created during the
|
|
build on the host system.
|
|
These scripts cannot attempt to run during first-boot on the
|
|
target device.
|
|
With the <filename>read-only-rootfs</filename> feature enabled,
|
|
the build system checks during root filesystem creation to make
|
|
sure all post-installation scripts succeed.
|
|
If any of these scripts still need to be run after the root
|
|
filesystem is created, the build immediately fails.
|
|
These checks during build time ensure that the build fails
|
|
rather than the target device fails later during its
|
|
initial boot operation.
|
|
</para>
|
|
|
|
<para>
|
|
Most of the common post-installation scripts generated by the
|
|
build system for the out-of-the-box Yocto Project are engineered
|
|
so that they can run during root filesystem creation
|
|
(e.g. post-installation scripts for caching fonts).
|
|
However, if you create and add custom scripts, you need
|
|
to be sure they can be run during file system creation.
|
|
</para>
|
|
|
|
<para>
|
|
Here are some common problems that prevent
|
|
post-installation scripts from running during root filesystem
|
|
creation:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Not using $D in front of absolute paths:</emphasis>
|
|
The build system defines
|
|
<filename>$</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-D'><filename>D</filename></ulink>
|
|
at root filesystem creation time, and
|
|
it is blank when run on the target device.
|
|
This implies two purposes for <filename>$D</filename>:
|
|
ensuring paths are valid in both the host and target
|
|
environments, and checking to determine which
|
|
environment is being used as a method for taking
|
|
appropriate actions.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Attempting to run processes that are
|
|
specific to or dependent on the target
|
|
architecture:</emphasis>
|
|
You can work around these attempts by using native
|
|
tools to accomplish the same tasks, or
|
|
by alternatively running the processes under QEMU,
|
|
which has the <filename>qemu_run_binary</filename>
|
|
function.
|
|
For more information, see the
|
|
<filename>meta/classes/qemu.bbclass</filename>
|
|
class in the
|
|
<link linkend='source-directory'>Source Directory</link>.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='areas-with-write-access'>
|
|
<title>Areas With Write Access</title>
|
|
|
|
<para>
|
|
With the <filename>read-only-rootfs</filename> feature enabled,
|
|
any attempt by the target to write to the root filesystem at
|
|
runtime fails.
|
|
Consequently, you must make sure that you configure processes
|
|
and applications that attempt these types of writes do so
|
|
to directories with write access (e.g.
|
|
<filename>/tmp</filename> or <filename>/var/run</filename>).
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="performing-automated-runtime-testing">
|
|
<title>Performing Automated Runtime Testing</title>
|
|
|
|
<para>
|
|
The OpenEmbedded build system makes available a series of automated
|
|
tests for images to verify runtime functionality.
|
|
<note>
|
|
Currently, there is only support for running these tests
|
|
under QEMU.
|
|
</note>
|
|
These tests are written in Python making use of the
|
|
<filename>unittest</filename> module, and the majority of them
|
|
run commands on the target system over
|
|
<filename>ssh</filename>.
|
|
This section describes how you set up the environment to use these
|
|
tests, run available tests, and write and add your own tests.
|
|
</para>
|
|
|
|
<section id="qemu-image-enabling-tests">
|
|
<title>Enabling Tests</title>
|
|
|
|
<para>
|
|
In order to run tests, you need to do the following:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Set up to avoid interaction
|
|
with <filename>sudo</filename> for networking:</emphasis>
|
|
To accomplish this, you must do one of the
|
|
following:
|
|
<itemizedlist>
|
|
<listitem><para>Add
|
|
<filename>NOPASSWD</filename> for your user
|
|
in <filename>/etc/sudoers</filename> either for
|
|
ALL commands or just for
|
|
<filename>runqemu-ifup</filename>.
|
|
You must provide the full path as that can
|
|
change if you are using multiple clones of the
|
|
source repository.
|
|
<note>
|
|
On some distributions, you also need to
|
|
comment out "Defaults requiretty" in
|
|
<filename>/etc/sudoers</filename>.
|
|
</note></para></listitem>
|
|
<listitem><para>Manually configure a tap interface
|
|
for your system.</para></listitem>
|
|
<listitem><para>Run as root the script in
|
|
<filename>scripts/runqemu-gen-tapdevs</filename>,
|
|
which should generate a list of tap devices.
|
|
This is the option typically chosen for
|
|
Autobuilder-type environments.
|
|
</para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
<listitem><para><emphasis>Set the
|
|
<filename>DISPLAY</filename> variable:</emphasis>
|
|
You need to set this variable so that you have an X
|
|
server available (e.g. start
|
|
<filename>vncserver</filename> for a headless machine).
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Be sure your host's firewall
|
|
accepts incoming connections from
|
|
192.168.7.0/24:</emphasis>
|
|
Some of the tests (in particular smart tests) start a
|
|
HTTP server on a random high number port, which is
|
|
used to serve files to the target.
|
|
The smart module serves
|
|
<filename>${DEPLOY_DIR}/rpm</filename> so it can run
|
|
smart channel commands. That means your host's firewall
|
|
must accept incoming connections from 192.168.7.0/24,
|
|
which is the default IP range used for tap devices
|
|
by <filename>runqemu</filename>.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<note>
|
|
Regardless of how you initiate the tests, if you built your
|
|
image using <filename>rm_work</filename>,
|
|
most of the tests will fail with errors because they rely on
|
|
<filename>${WORKDIR}/installed_pkgs.txt</filename>.
|
|
</note>
|
|
</section>
|
|
|
|
<section id="qemu-image-running-tests">
|
|
<title>Running Tests</title>
|
|
|
|
<para>
|
|
You can start the tests automatically or manually:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Automatically Running Tests:</emphasis>
|
|
To run the tests automatically after the
|
|
OpenEmbedded build system successfully creates an image,
|
|
first set the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-TEST_IMAGE'><filename>TEST_IMAGE</filename></ulink>
|
|
variable to "1" in your <filename>local.conf</filename>
|
|
file in the
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink>:
|
|
<literallayout class='monospaced'>
|
|
TEST_IMAGE = "1"
|
|
</literallayout>
|
|
Next, simply build your image.
|
|
If the image successfully builds, the tests will be
|
|
run:
|
|
<literallayout class='monospaced'>
|
|
bitbake core-image-sato
|
|
</literallayout></para></listitem>
|
|
<listitem><para><emphasis>Manually Running Tests:</emphasis>
|
|
To manually run the tests, first globally inherit
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-testimage'><filename>testimage.class</filename></ulink>
|
|
by editing your <filename>local.conf</filename> file:
|
|
<literallayout class='monospaced'>
|
|
INHERIT += "testimage"
|
|
</literallayout>
|
|
Next, use BitBake to run the tests:
|
|
<literallayout class='monospaced'>
|
|
bitbake -c testimage <image>
|
|
</literallayout></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Regardless of how you run the tests, once they start, the
|
|
following happens:
|
|
<itemizedlist>
|
|
<listitem><para>A copy of the root filesystem is written
|
|
to <filename>${WORKDIR}/testimage</filename>.
|
|
</para></listitem>
|
|
<listitem><para>The image is booted under QEMU using the
|
|
standard <filename>runqemu</filename> script.
|
|
</para></listitem>
|
|
<listitem><para>A default timeout of 500 seconds occurs
|
|
to allow for the boot process to reach the login prompt.
|
|
You can change the timeout period by setting
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-TEST_QEMUBOOT_TIMEOUT'><filename>TEST_QEMUBOOT_TIMEOUT</filename></ulink>
|
|
in the <filename>local.conf</filename> file.
|
|
</para></listitem>
|
|
<listitem><para>Once the boot process is reached and the
|
|
login prompt appears, the tests run.
|
|
The full boot log is written to
|
|
<filename>${WORKDIR}/testimage/qemu_boot_log</filename>.
|
|
</para></listitem>
|
|
<listitem><para>Each test module loads in the order found
|
|
in <filename>TEST_SUITES</filename>.
|
|
You can find the full output of the commands run over
|
|
<filename>ssh</filename> in
|
|
<filename>${WORKDIR}/testimgage/ssh_target_log</filename>.
|
|
</para></listitem>
|
|
<listitem><para>If no failures occur, the task running the
|
|
tests ends successfully.
|
|
You can find the output from the
|
|
<filename>unittest</filename> in the task log at
|
|
<filename>${WORKDIR}/temp/log.do_testimage</filename>.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
All test files reside in
|
|
<filename>meta/lib/oeqa/runtime</filename> in the
|
|
<link linkend='source-directory'>Source Directory</link>.
|
|
A test name maps directly to a Python module.
|
|
Each test module may contain a number of individual tests.
|
|
Tests are usually grouped together by the area
|
|
tested (e.g tests for <filename>systemd</filename> reside in
|
|
<filename>meta/lib/oeqa/runtime/systemd.py</filename>).
|
|
</para>
|
|
|
|
<para>
|
|
You can add tests to any layer provided you place them in the
|
|
proper area and you extend
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBPATH'><filename>BBPATH</filename></ulink>
|
|
in the <filename>local.conf</filename> file as normal.
|
|
Be sure that tests reside in
|
|
<filename><layer>/lib/oeqa/runtime</filename>.
|
|
<note>
|
|
Be sure that module names do not collide with module names
|
|
used in the default set of test modules in
|
|
<filename>meta/lib/oeqa/runtime</filename>.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
You can change the set of tests run by appending or overriding
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-TEST_SUITES'><filename>TEST_SUITES</filename></ulink>
|
|
variable in <filename>local.conf</filename>.
|
|
Each name in <filename>TEST_SUITES</filename> represents a
|
|
required test for the image.
|
|
Test modules named within <filename>TEST_SUITES</filename>
|
|
cannot be skipped even if a test is not suitable for an image
|
|
(e.g. running the rpm tests on an image without
|
|
<filename>rpm</filename>).
|
|
Appending "auto" to <filename>TEST_SUITES</filename> causes the
|
|
build system to try to run all tests that are suitable for the
|
|
image (i.e. each test module may elect to skip itself).
|
|
</para>
|
|
|
|
<para>
|
|
The order you list tests in <filename>TEST_SUITES</filename>
|
|
is important.
|
|
The order influences test dependencies.
|
|
Consequently, tests that depend on other tests should be added
|
|
after the test on which they depend.
|
|
For example, since <filename>ssh</filename> depends on the
|
|
<filename>ping</filename> test, <filename>ssh</filename>
|
|
needs to come after <filename>ping</filename> in the list.
|
|
The test class provides no re-ordering or dependency handling.
|
|
<note>
|
|
Each module can have multiple classes with multiple test
|
|
methods.
|
|
And, Python <filename>unittest</filename> rules apply.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
Here are some things to keep in mind when running tests:
|
|
<itemizedlist>
|
|
<listitem><para>The default tests for the image are defined
|
|
as:
|
|
<literallayout class='monospaced'>
|
|
DEFAULT_TEST_SUITES_pn-<image> = "ping ssh df connman syslog xorg scp vnc date rpm smart dmesg"
|
|
</literallayout></para></listitem>
|
|
<listitem><para>Add your own test to the list of the
|
|
by using the following:
|
|
<literallayout class='monospaced'>
|
|
TEST_SUITES_append = " mytest"
|
|
</literallayout></para></listitem>
|
|
<listitem><para>Run a specific list of tests as follows:
|
|
<literallayout class='monospaced'>
|
|
TEST_SUITES = "test1 test2 test3"
|
|
</literallayout>
|
|
Remember, order is important.
|
|
Be sure to place a test that is dependent on another test
|
|
later in the order.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="qemu-image-writing-new-tests">
|
|
<title>Writing New Tests</title>
|
|
|
|
<para>
|
|
As mentioned previously, all new test files need to be in the
|
|
proper place for the build system to find them.
|
|
New tests for additional functionality outside of the core
|
|
should be added to the layer that adds the functionality, in
|
|
<filename><layer>/lib/oeqa/runtime</filename> (as
|
|
long as
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-BBPATH'><filename>BBPATH</filename></ulink>
|
|
is extended in the layer's
|
|
<filename>layer.conf</filename> file as normal).
|
|
Just remember that filenames need to map directly to test
|
|
(module) names and that you do not use module names that
|
|
collide with existing core tests.
|
|
</para>
|
|
|
|
<para>
|
|
To create a new test, start by copying an existing module
|
|
(e.g. <filename>syslog.py</filename> or
|
|
<filename>gcc.py</filename> are good ones to use).
|
|
Test modules can use code from
|
|
<filename>meta/lib/oeqa/utils</filename>, which are helper
|
|
classes.
|
|
</para>
|
|
|
|
<note>
|
|
Structure shell commands such that you rely on them and they
|
|
return a single code for success.
|
|
Be aware that sometimes you will need to parse the output.
|
|
See the <filename>df.py</filename> and
|
|
<filename>date.py</filename> modules for examples.
|
|
</note>
|
|
|
|
<para>
|
|
You will notice that all test classes inherit
|
|
<filename>oeRuntimeTest</filename>, which is found in
|
|
<filename>meta/lib/oetest.py</filename>.
|
|
This base class offers some helper attributes, which are
|
|
described in the following sections:
|
|
</para>
|
|
|
|
<section id='qemu-image-writing-tests-class-methods'>
|
|
<title>Class Methods</title>
|
|
|
|
<para>
|
|
Class methods are as follows:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>hasPackage(pkg)</filename>:</emphasis>
|
|
Returns "True" if <filename>pkg</filename> is in the
|
|
installed package list of the image, which is based
|
|
on
|
|
<filename>${WORKDIR}/installed_pkgs.txt</filename>
|
|
that is generated during the
|
|
<filename>do.rootfs</filename> task.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>hasFeature(feature)</filename>:</emphasis>
|
|
Returns "True" if the feature is in
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></ulink>
|
|
or
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></ulink>.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>restartTarget(params)</filename>:</emphasis>
|
|
Restarts the QEMU image optionally passing
|
|
<filename>params</filename> to the
|
|
<filename>runqemu</filename> script's
|
|
<filename>qemuparams</filename> list (e.g "-m 1024" for
|
|
more memory).</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='qemu-image-writing-tests-class-attributes'>
|
|
<title>Class Attributes</title>
|
|
|
|
<para>
|
|
Class attributes are as follows:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>pscmd</filename>:</emphasis>
|
|
Equals "ps -ef" if <filename>procps</filename> is
|
|
installed in the image.
|
|
Otherwise, <filename>pscmd</filename> equals
|
|
"ps" (busybox).
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>tc</filename>:</emphasis>
|
|
The called text context, which gives access to the
|
|
following attributes:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>d</filename>:</emphasis>
|
|
The BitBake data store, which allows you to
|
|
use stuff such as
|
|
<filename>oeRuntimeTest.tc.d.getVar("VIRTUAL-RUNTIME_init_manager")</filename>.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>testslist</filename> and <filename>testsrequired</filename>:</emphasis>
|
|
Used internally.
|
|
The tests do not need these.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>filesdir</filename>:</emphasis>
|
|
The absolute path to
|
|
<filename>meta/lib/oeqa/runtime/files</filename>,
|
|
which contains helper files for tests meant
|
|
for copying on the target such as small
|
|
files written in C for compilation.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>qemu</filename>:</emphasis>
|
|
Provides access to the
|
|
<filename>QemuRunner</filename> object,
|
|
which is the class that boots the image.
|
|
The <filename>qemu</filename> attribute
|
|
provides the following useful attributes:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>ip</filename>:</emphasis>
|
|
The machine's IP address.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>host_ip</filename>:</emphasis>
|
|
The host IP address, which is only
|
|
used by smart tests.
|
|
</para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
<listitem><para><emphasis><filename>target</filename>:</emphasis>
|
|
The <filename>SSHControl</filename> object,
|
|
which is used for running the following
|
|
commands on the image:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>host</filename>:</emphasis>
|
|
Used internally.
|
|
The tests do not use this command.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>timeout</filename>:</emphasis>
|
|
A global timeout for commands run on
|
|
the target for the instance of a
|
|
test.
|
|
The default is 300 seconds.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>run(cmd, timeout=None)</filename>:</emphasis>
|
|
The single, most used method.
|
|
This command is a wrapper for:
|
|
<filename>ssh root@host "cmd"</filename>.
|
|
The command returns a tuple:
|
|
(status, output), which are what
|
|
their names imply - the return code
|
|
of 'cmd' and whatever output
|
|
it produces.
|
|
The optional timeout argument
|
|
represents the number of seconds the
|
|
test should wait for 'cmd' to
|
|
return.
|
|
If the argument is "None", the
|
|
test uses the default instance's
|
|
timeout period, which is 300
|
|
seconds.
|
|
If the argument is "0", the test
|
|
runs until the command returns.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>copy_to(localpath, remotepath)</filename>:</emphasis>
|
|
<filename>scp localpath root@ip:remotepath</filename>.
|
|
</para></listitem>
|
|
<listitem><para><emphasis><filename>copy_from(remotepath, localpath)</filename>:</emphasis>
|
|
<filename>scp root@host:remotepath localpath</filename>.
|
|
</para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
</itemizedlist></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='qemu-image-writing-tests-instance-attributes'>
|
|
<title>Instance Attributes</title>
|
|
|
|
<para>
|
|
A single instance attribute exists, which is
|
|
<filename>target</filename>.
|
|
The <filename>target</filename> instance attribute is
|
|
identical to the class attribute of the same name, which
|
|
is described in the previous section.
|
|
This attribute exists as both an instance and class
|
|
attribute so tests can use
|
|
<filename>self.target.run(cmd)</filename> in instance
|
|
methods instead of
|
|
<filename>oeRuntimeTest.tc.target.run(cmd)</filename>.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="platdev-gdb-remotedebug">
|
|
<title>Debugging With the GNU Project Debugger (GDB) Remotely</title>
|
|
|
|
<para>
|
|
GDB allows you to examine running programs, which in turn helps you to understand and fix problems.
|
|
It also allows you to perform post-mortem style analysis of program crashes.
|
|
GDB is available as a package within the Yocto Project and is
|
|
installed in SDK images by default.
|
|
See the "<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Images</ulink>" chapter
|
|
in the Yocto Project Reference Manual for a description of these images.
|
|
You can find information on GDB at <ulink url="http://sourceware.org/gdb/"/>.
|
|
</para>
|
|
|
|
<tip>
|
|
For best results, install <filename>-dbg</filename> packages for
|
|
the applications you are going to debug.
|
|
Doing so makes extra debug symbols available that give you more
|
|
meaningful output.
|
|
</tip>
|
|
|
|
<para>
|
|
Sometimes, due to memory or disk space constraints, it is not possible
|
|
to use GDB directly on the remote target to debug applications.
|
|
These constraints arise because GDB needs to load the debugging information and the
|
|
binaries of the process being debugged.
|
|
Additionally, GDB needs to perform many computations to locate information such as function
|
|
names, variable names and values, stack traces and so forth - even before starting the
|
|
debugging process.
|
|
These extra computations place more load on the target system and can alter the
|
|
characteristics of the program being debugged.
|
|
</para>
|
|
|
|
<para>
|
|
To help get past the previously mentioned constraints, you can use Gdbserver.
|
|
Gdbserver runs on the remote target and does not load any debugging information
|
|
from the debugged process.
|
|
Instead, a GDB instance processes the debugging information that is run on a
|
|
remote computer - the host GDB.
|
|
The host GDB then sends control commands to Gdbserver to make it stop or start the debugged
|
|
program, as well as read or write memory regions of that debugged program.
|
|
All the debugging information loaded and processed as well
|
|
as all the heavy debugging is done by the host GDB.
|
|
Offloading these processes gives the Gdbserver running on the target a chance to remain
|
|
small and fast.
|
|
</para>
|
|
|
|
<para>
|
|
Because the host GDB is responsible for loading the debugging information and
|
|
for doing the necessary processing to make actual debugging happen, the
|
|
user has to make sure the host can access the unstripped binaries complete
|
|
with their debugging information and also be sure the target is compiled with no optimizations.
|
|
The host GDB must also have local access to all the libraries used by the
|
|
debugged program.
|
|
Because Gdbserver does not need any local debugging information, the binaries on
|
|
the remote target can remain stripped.
|
|
However, the binaries must also be compiled without optimization
|
|
so they match the host's binaries.
|
|
</para>
|
|
|
|
<para>
|
|
To remain consistent with GDB documentation and terminology, the binary being debugged
|
|
on the remote target machine is referred to as the "inferior" binary.
|
|
For documentation on GDB see the
|
|
<ulink url="http://sourceware.org/gdb/documentation/">GDB site</ulink>.
|
|
</para>
|
|
|
|
<para>
|
|
The remainder of this section describes the steps you need to take
|
|
to debug using the GNU project debugger.
|
|
</para>
|
|
|
|
<section id='platdev-gdb-remotedebug-setup'>
|
|
<title>Set Up the Cross-Development Debugging Environment</title>
|
|
|
|
<para>
|
|
Before you can initiate a remote debugging session, you need
|
|
to be sure you have set up the cross-development environment,
|
|
toolchain, and sysroot.
|
|
The "<ulink url='&YOCTO_DOCS_ADT_URL;#adt-prepare'>Preparing for Application Development</ulink>"
|
|
chapter of the Yocto Project Application Developer's Guide
|
|
describes this process.
|
|
Be sure you have read that chapter and have set up
|
|
your environment.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-gdb-remotedebug-launch-gdbserver">
|
|
<title>Launch Gdbserver on the Target</title>
|
|
|
|
<para>
|
|
Make sure Gdbserver is installed on the target.
|
|
If it is not, install the package
|
|
<filename>gdbserver</filename>, which needs the
|
|
<filename>libthread-db1</filename> package.
|
|
</para>
|
|
|
|
<para>
|
|
Here is an example that when entered from the host
|
|
connects to the target and launches Gdbserver in order to
|
|
"debug" a binary named <filename>helloworld</filename>:
|
|
<literallayout class='monospaced'>
|
|
$ gdbserver localhost:2345 /usr/bin/helloworld
|
|
</literallayout>
|
|
Gdbserver should now be listening on port 2345 for debugging
|
|
commands coming from a remote GDB process that is running on
|
|
the host computer.
|
|
Communication between Gdbserver and the host GDB are done
|
|
using TCP.
|
|
To use other communication protocols, please refer to the
|
|
<ulink url='http://www.gnu.org/software/gdb/'>Gdbserver documentation</ulink>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-gdb-remotedebug-launch-gdb">
|
|
<title>Launch GDB on the Host Computer</title>
|
|
|
|
<para>
|
|
Running GDB on the host computer takes a number of stages, which
|
|
this section describes.
|
|
</para>
|
|
|
|
<section id="platdev-gdb-remotedebug-launch-gdb-buildcross">
|
|
<title>Build the Cross-GDB Package</title>
|
|
<para>
|
|
A suitable GDB cross-binary is required that runs on your
|
|
host computer but also knows about the the ABI of the
|
|
remote target.
|
|
You can get this binary from the
|
|
<link linkend='cross-development-toolchain'>Cross-Development Toolchain</link>.
|
|
Here is an example where the toolchain has been installed
|
|
in the default directory
|
|
<filename>/opt/poky/&DISTRO;</filename>:
|
|
<literallayout class='monospaced'>
|
|
/opt/poky/1.4/sysroots/i686-pokysdk-linux/usr/bin/armv7a-vfp-neon-poky-linux-gnueabi/arm-poky-linux-gnueabi-gdb
|
|
</literallayout>
|
|
where <filename>arm</filename> is the target architecture
|
|
and <filename>linux-gnueabi</filename> is the target ABI.
|
|
</para>
|
|
|
|
<para>
|
|
Alternatively, you can use BitBake to build the
|
|
<filename>gdb-cross</filename> binary.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
$ bitbake gdb-cross
|
|
</literallayout>
|
|
Once the binary is built, you can find it here:
|
|
<literallayout class='monospaced'>
|
|
tmp/sysroots/<host-arch>/usr/bin/<target-platform>/<target-abi>-gdb
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='create-the-gdb-initialization-file'>
|
|
<title>Create the GDB Initialization File and Point to Your Root Filesystem</title>
|
|
|
|
<para>
|
|
Aside from the GDB cross-binary, you also need a GDB
|
|
initialization file in the same top directory in which
|
|
your binary resides.
|
|
When you start GDB on your host development system, GDB
|
|
finds this initialization file and executes all the
|
|
commands within.
|
|
For information on the <filename>.gdbinit</filename>, see
|
|
"<ulink url='http://sourceware.org/gdb/onlinedocs/gdb/'>Debugging with GDB</ulink>",
|
|
which is maintained by
|
|
<ulink url='http://www.sourceware.org'>sourceware.org</ulink>.
|
|
</para>
|
|
|
|
<para>
|
|
You need to add a statement in the
|
|
<filename>.gdbinit</filename> file that points to your
|
|
root filesystem.
|
|
Here is an example that points to the root filesystem for
|
|
an ARM-based target device:
|
|
<literallayout class='monospaced'>
|
|
set sysroot /home/jzhang/sysroot_arm
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-gdb-remotedebug-launch-gdb-launchhost">
|
|
<title>Launch the Host GDB</title>
|
|
|
|
<para>
|
|
Before launching the host GDB, you need to be sure
|
|
you have sourced the cross-debugging environment script,
|
|
which if you installed the root filesystem in the default
|
|
location is at <filename>/opt/poky/&DISTRO;</filename>
|
|
and begins with the string "environment-setup".
|
|
For more information, see the
|
|
"<ulink url='&YOCTO_DOCS_ADT_URL;#setting-up-the-cross-development-environment'>Setting Up the Cross-Development Environment</ulink>"
|
|
section in the Yocto Project Application Developer's
|
|
Guide.
|
|
</para>
|
|
|
|
<para>
|
|
Finally, switch to the directory where the binary resides
|
|
and run the <filename>cross-gdb</filename> binary.
|
|
Provide the binary file you are going to debug.
|
|
For example, the following command continues with the
|
|
example used in the previous section by loading
|
|
the <filename>helloworld</filename> binary as well as the
|
|
debugging information:
|
|
<literallayout class='monospaced'>
|
|
$ arm-poky-linux-gnuabi-gdb helloworld
|
|
</literallayout>
|
|
The commands in your <filename>.gdbinit</filename> execute
|
|
and the GDB prompt appears.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='platdev-gdb-connect-to-the-remote-gdb-server'>
|
|
<title>Connect to the Remote GDB Server</title>
|
|
|
|
<para>
|
|
From the target, you need to connect to the remote GDB
|
|
server that is running on the host.
|
|
You need to specify the remote host and port.
|
|
Here is the command continuing with the example:
|
|
<literallayout class='monospaced'>
|
|
target remote 192.168.7.2:2345
|
|
</literallayout>
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-gdb-remotedebug-launch-gdb-using">
|
|
<title>Use the Debugger</title>
|
|
|
|
<para>
|
|
You can now proceed with debugging as normal - as if you were debugging
|
|
on the local machine.
|
|
For example, to instruct GDB to break in the "main" function and then
|
|
continue with execution of the inferior binary use the following commands
|
|
from within GDB:
|
|
<literallayout class='monospaced'>
|
|
(gdb) break main
|
|
(gdb) continue
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
For more information about using GDB, see the project's online documentation at
|
|
<ulink url="http://sourceware.org/gdb/download/onlinedocs/"/>.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id="examining-builds-using-toaster">
|
|
<title>Examining Builds Using the Toaster API</title>
|
|
|
|
<para>
|
|
Toaster is an Application Programming Interface (API) to the
|
|
OpenEmbedded build system, which uses BitBake.
|
|
The interface is a Representational State Transfer (REST) API
|
|
that queries for and returns build information using
|
|
<filename>GET</filename> and <filename>JSON</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
Through the API you can do the following:
|
|
<itemizedlist>
|
|
<listitem><para>See information about the tasks executed
|
|
and reused during the build.</para></listitem>
|
|
<listitem><para>See what is built (recipes and
|
|
packages) and what packages were installed into the final
|
|
image.</para></listitem>
|
|
<listitem><para>See performance-related information such
|
|
as build time, CPU usage, and disk I/O.</para></listitem>
|
|
<listitem><para>Examine error, warning and trace messages
|
|
to aid in debugging.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
In summary, the search operation retrieves a set of objects from
|
|
a data store used to collect build information.
|
|
The result contains all the data for the objects being returned.
|
|
You can order the results of the search by key and the search
|
|
parameters are consistent for all object types.
|
|
</para>
|
|
|
|
<para>
|
|
For more information on installing and running Toaster, see the
|
|
"<ulink url='https://wiki.yoctoproject.org/wiki/Web_Hob#Installation_and_Running'>Installation and Running</ulink>"
|
|
section of the "Toaster" wiki page.
|
|
For complete information on the API and its search operation
|
|
URI, parameters, and responses, see the
|
|
<ulink url='https://wiki.yoctoproject.org/wiki/REST_API_Contracts'>REST API Contracts</ulink>
|
|
Wiki page.
|
|
</para>
|
|
</section>
|
|
|
|
<!-- Commenting out the Toaster GUI stuff as it did not make it for 1.5
|
|
|
|
<section id="examining-builds-using-toaster">
|
|
<title>Examining Builds using Toaster</title>
|
|
|
|
<para>
|
|
Toaster is a Web-based interface to the OpenEmbedded build system,
|
|
which uses BitBake.
|
|
Toaster offers features to record and analyze BitBake runs applied
|
|
to a specific target.
|
|
Using Toaster, you can do the following:
|
|
<itemizedlist>
|
|
<listitem><para>See information about the tasks executed
|
|
and reused during the build.</para></listitem>
|
|
<listitem><para>See what is built (recipes and
|
|
packages) and what packages were installed into the final
|
|
image.</para></listitem>
|
|
<listitem><para>See performance-related information such
|
|
as build time, CPU usage, and disk I/O.</para></listitem>
|
|
<listitem><para>Examine error, warning and trace messages
|
|
to aid in debugging.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<note>
|
|
<para>This release of Toaster provides you with information
|
|
about a BitBake run.
|
|
The tool does not allow you to configure and launch a build.
|
|
Future development includes plans to integrate the data examination
|
|
features of Toaster with the configuration and build launching
|
|
capabilities of
|
|
<ulink url='&YOCTO_HOME_URL;/tools-resources/projects/hob'>Hob</ulink>.
|
|
</para>
|
|
<para>For more information on using Hob to build an image,
|
|
see the
|
|
"<link linkend='image-development-using-hob'>Image Development Using Hob</link>"
|
|
section.</para>
|
|
</note>
|
|
|
|
<section id='starting-toaster'>
|
|
<title>Starting Toaster</title>
|
|
|
|
<para>
|
|
Getting set up to use and start Toaster is simple.
|
|
First, be sure you have met the following requirements:
|
|
<itemizedlist>
|
|
<listitem><para>You have set up your
|
|
<link linkend='source-directory'>Source Directory</link>.
|
|
See the
|
|
<link linkend='local-yp-release'>Yocto Project Release</link>
|
|
item for information on how to set up the Source
|
|
Directory.</para></listitem>
|
|
<listitem><para>Be sure your build machine has
|
|
<ulink url='http://en.wikipedia.org/wiki/Django_%28web_framework%29'>Django</ulink>
|
|
version 1.4 or greater installed.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Once you have met the requirements, follow these steps to
|
|
start Toaster running in the background of your shell:
|
|
<orderedlist>
|
|
<listitem><para>Set up your build environment by sourcing
|
|
the <filename>oe-init-build-env</filename> script.
|
|
</para></listitem>
|
|
<listitem><para>Edit your <filename>local.conf</filename>
|
|
configuration file as needed.</para></listitem>
|
|
<listitem><para>Start the Toaster service using this
|
|
command from within your build directory:
|
|
<literallayout class='monospaced'>
|
|
$ source toaster start
|
|
</literallayout></para></listitem>
|
|
<note>
|
|
The Toaster must be started and running in order
|
|
for it to collect data.
|
|
</note>
|
|
</orderedlist>
|
|
</para>
|
|
|
|
<para>
|
|
When Toaster starts, it creates some additional files in your
|
|
Build Directory.
|
|
Deleting these files will cause you to lose data or interrupt
|
|
Toaster:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis><filename>toaster.sqlite</filename>:</emphasis>
|
|
Toaster's database file.</para></listitem>
|
|
<listitem><para><emphasis><filename>tstmain.log</filename>:</emphasis>
|
|
Toaster's log file.</para></listitem>
|
|
<listitem><para><emphasis><filename>tstmain.pid</filename>:</emphasis>
|
|
Contains the PID of the web server.</para></listitem>
|
|
<listitem><para><emphasis><filename>dsi.pid</filename>:</emphasis>
|
|
Contains the PID of th bridge.</para></listitem>
|
|
<listitem><para><emphasis><filename>bitbake-cookerdaemon.log</filename>:</emphasis>
|
|
The BitBake server's log file.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='using-toaster'>
|
|
<title>Using Toaster</title>
|
|
|
|
<para>
|
|
Once Toaster is running, it logs information for any BitBake
|
|
run from your Build Directory.
|
|
This logging is automatic.
|
|
All you need to do is access and use the information.
|
|
</para>
|
|
|
|
<para>
|
|
You access the information one of two ways:
|
|
<itemizedlist>
|
|
<listitem><para>Open a Browser and type enter in the
|
|
<filename>http://localhost:8000</filename> URL.
|
|
</para></listitem>
|
|
<listitem><para>Use the <filename>xdg-open</filename>
|
|
tool from the shell and pass it the same URL.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
Either method opens the home page for the Toaster interface.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='examining-toaster-data'>
|
|
<title>Examining Toaster Data</title>
|
|
|
|
<para>
|
|
The Toaster database is persistent regardless of whether you
|
|
start or stop the service.
|
|
</para>
|
|
|
|
<para>
|
|
Toaster's interface shows you a list of builds
|
|
(successful and unsuccessful) for which it has data.
|
|
You can click on any build to see related information.
|
|
This information includes configuration details, information
|
|
about tasks, all recipes and packages built and their
|
|
dependencies, packages installed in your final image,
|
|
execution time, CPU usage and disk I/O per task.
|
|
</para>
|
|
|
|
<para>
|
|
The home page of the interface into the database organizes
|
|
builds into areas:
|
|
<itemizedlist>
|
|
<listitem><para>Recent successful builds, which appear
|
|
in row format in a green area.</para></listitem>
|
|
<listitem><para>Recent failed builds, which appear
|
|
in row format in a red area.</para></listitem>
|
|
<listitem><para>Recent builds in progress, which appear
|
|
in row format in a yellow area.</para></listitem>
|
|
<listitem><para>All builds, which appear in row format at
|
|
the end of the page.</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Each entry is linked to more detail on the particular build
|
|
or recipe.
|
|
You can click on the links to learn more information.
|
|
</para>
|
|
|
|
<para>
|
|
When you click on a failed recipe link, you can find out
|
|
information such as the work directory, the pathname to the
|
|
failing recipe, the exact error message, and precursor tasks.
|
|
</para>
|
|
|
|
<para>
|
|
Clicking on a successful build provides you with configuration,
|
|
task, and package information along with directory structure,
|
|
build time, CPU usage, and disk I/O information.
|
|
</para>
|
|
|
|
</section>
|
|
|
|
<section id='stopping-toaster'>
|
|
<title>Stopping Toaster</title>
|
|
|
|
<para>
|
|
Stop the Toaster service with the following command:
|
|
<literallayout class='monospaced'>
|
|
$ source toaster stop
|
|
</literallayout>
|
|
The service stops but the Toaster database remains persistent.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
-->
|
|
|
|
<section id="platdev-oprofile">
|
|
<title>Profiling with OProfile</title>
|
|
|
|
<para>
|
|
<ulink url="http://oprofile.sourceforge.net/">OProfile</ulink> is a
|
|
statistical profiler well suited for finding performance
|
|
bottlenecks in both user-space software and in the kernel.
|
|
This profiler provides answers to questions like "Which functions does my application spend
|
|
the most time in when doing X?"
|
|
Because the OpenEmbedded build system is well integrated with OProfile, it makes profiling
|
|
applications on target hardware straightforward.
|
|
<note>
|
|
For more information on how to set up and run OProfile, see the
|
|
"<ulink url='&YOCTO_DOCS_PROF_URL;#profile-manual-oprofile'>OProfile</ulink>"
|
|
section in the Yocto Project Profiling and Tracing Manual.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
To use OProfile, you need an image that has OProfile installed.
|
|
The easiest way to do this is with <filename>tools-profile</filename> in the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FEATURES'>IMAGE_FEATURES</ulink></filename> variable.
|
|
You also need debugging symbols to be available on the system where the analysis
|
|
takes place.
|
|
You can gain access to the symbols by using <filename>dbg-pkgs</filename> in the
|
|
<filename>IMAGE_FEATURES</filename> variable or by
|
|
installing the appropriate <filename>-dbg</filename> packages.
|
|
</para>
|
|
|
|
<para>
|
|
For successful call graph analysis, the binaries must preserve the frame
|
|
pointer register and should also be compiled with the
|
|
<filename>-fno-omit-framepointer</filename> flag.
|
|
You can achieve this by setting the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-SELECTED_OPTIMIZATION'>SELECTED_OPTIMIZATION</ulink></filename>
|
|
variable with the following options:
|
|
<literallayout class='monospaced'>
|
|
-fexpensive-optimizations
|
|
-fno-omit-framepointer
|
|
-frename-registers
|
|
-O2
|
|
</literallayout>
|
|
You can also achieve it by setting the
|
|
<filename><ulink url='&YOCTO_DOCS_REF_URL;#var-DEBUG_BUILD'>DEBUG_BUILD</ulink></filename>
|
|
variable to "1" in the <filename>local.conf</filename> configuration file.
|
|
If you use the <filename>DEBUG_BUILD</filename> variable,
|
|
you also add extra debugging information that can make the debug
|
|
packages large.
|
|
</para>
|
|
|
|
<section id="platdev-oprofile-target">
|
|
<title>Profiling on the Target</title>
|
|
|
|
<para>
|
|
Using OProfile you can perform all the profiling work on the target device.
|
|
A simple OProfile session might look like the following:
|
|
</para>
|
|
|
|
<para>
|
|
<literallayout class='monospaced'>
|
|
# opcontrol --reset
|
|
# opcontrol --start --separate=lib --no-vmlinux -c 5
|
|
.
|
|
.
|
|
[do whatever is being profiled]
|
|
.
|
|
.
|
|
# opcontrol --stop
|
|
$ opreport -cl
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
In this example, the <filename>reset</filename> command clears any previously profiled data.
|
|
The next command starts OProfile.
|
|
The options used when starting the profiler separate dynamic library data
|
|
within applications, disable kernel profiling, and enable callgraphing up to
|
|
five levels deep.
|
|
<note>
|
|
To profile the kernel, you would specify the
|
|
<filename>--vmlinux=/path/to/vmlinux</filename> option.
|
|
The <filename>vmlinux</filename> file is usually in the source directory in the
|
|
<filename>/boot/</filename> directory and must match the running kernel.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
After you perform your profiling tasks, the next command stops the profiler.
|
|
After that, you can view results with the <filename>opreport</filename> command with options
|
|
to see the separate library symbols and callgraph information.
|
|
</para>
|
|
|
|
<para>
|
|
Callgraphing logs information about time spent in functions and about a function's
|
|
calling function (parent) and called functions (children).
|
|
The higher the callgraphing depth, the more accurate the results.
|
|
However, higher depths also increase the logging overhead.
|
|
Consequently, you should take care when setting the callgraphing depth.
|
|
<note>
|
|
On ARM, binaries need to have the frame pointer enabled for callgraphing to work.
|
|
To accomplish this use the <filename>-fno-omit-framepointer</filename> option
|
|
with <filename>gcc</filename>.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
For more information on using OProfile, see the OProfile
|
|
online documentation at
|
|
<ulink url="http://oprofile.sourceforge.net/docs/"/>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-oprofile-oprofileui">
|
|
<title>Using OProfileUI</title>
|
|
|
|
<para>
|
|
A graphical user interface for OProfile is also available.
|
|
You can download and build this interface from the Yocto Project at
|
|
<ulink url="&YOCTO_GIT_URL;/cgit.cgi/oprofileui/"></ulink>.
|
|
If the "tools-profile" image feature is selected, all necessary binaries
|
|
are installed onto the target device for OProfileUI interaction.
|
|
For a list of image features that ship with the Yocto Project,
|
|
see the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#ref-features-image'>Images</ulink>"
|
|
section in the Yocto Project Reference Manual.
|
|
</para>
|
|
|
|
<para>
|
|
Even though the source directory usually includes all needed patches on the target device, you
|
|
might find you need other OProfile patches for recent OProfileUI features.
|
|
If so, see the <ulink url='&YOCTO_GIT_URL;/cgit.cgi/oprofileui/tree/README'>
|
|
OProfileUI README</ulink> for the most recent information.
|
|
</para>
|
|
|
|
<section id="platdev-oprofile-oprofileui-online">
|
|
<title>Online Mode</title>
|
|
|
|
<para>
|
|
Using OProfile in online mode assumes a working network connection with the target
|
|
hardware.
|
|
With this connection, you just need to run "oprofile-server" on the device.
|
|
By default, OProfile listens on port 4224.
|
|
<note>
|
|
You can change the port using the <filename>--port</filename> command-line
|
|
option.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
The client program is called <filename>oprofile-viewer</filename> and its UI is relatively
|
|
straightforward.
|
|
You access key functionality through the buttons on the toolbar, which
|
|
are duplicated in the menus.
|
|
Here are the buttons:
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Connect:</emphasis> Connects to the remote host.
|
|
You can also supply the IP address or hostname.</para></listitem>
|
|
<listitem><para><emphasis>Disconnect:</emphasis> Disconnects from the target.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Start:</emphasis> Starts profiling on the device.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Stop:</emphasis> Stops profiling on the device and
|
|
downloads the data to the local host.
|
|
Stopping the profiler generates the profile and displays it in the viewer.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Download:</emphasis> Downloads the data from the
|
|
target and generates the profile, which appears in the viewer.</para></listitem>
|
|
<listitem><para><emphasis>Reset:</emphasis> Resets the sample data on the device.
|
|
Resetting the data removes sample information collected from previous
|
|
sampling runs.
|
|
Be sure you reset the data if you do not want to include old sample information.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Save:</emphasis> Saves the data downloaded from the
|
|
target to another directory for later examination.</para></listitem>
|
|
<listitem><para><emphasis>Open:</emphasis> Loads previously saved data.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
The client downloads the complete 'profile archive' from
|
|
the target to the host for processing.
|
|
This archive is a directory that contains the sample data, the object files,
|
|
and the debug information for the object files.
|
|
The archive is then converted using the <filename>oparchconv</filename> script, which is
|
|
included in this distribution.
|
|
The script uses <filename>opimport</filename> to convert the archive from
|
|
the target to something that can be processed on the host.
|
|
</para>
|
|
|
|
<para>
|
|
Downloaded archives reside in the
|
|
<link linkend='build-directory'>Build Directory</link> in
|
|
<filename>/tmp</filename> and are cleared up when they are no longer in use.
|
|
</para>
|
|
|
|
<para>
|
|
If you wish to perform kernel profiling, you need to be sure
|
|
a <filename>vmlinux</filename> file that matches the running kernel is available.
|
|
In the source directory, that file is usually located in
|
|
<filename>/boot/vmlinux-KERNELVERSION</filename>, where
|
|
<filename>KERNEL-version</filename> is the version of the kernel.
|
|
The OpenEmbedded build system generates separate <filename>vmlinux</filename>
|
|
packages for each kernel it builds.
|
|
Thus, it should just be a question of making sure a matching package is
|
|
installed (e.g. <filename>opkg install kernel-vmlinux</filename>).
|
|
The files are automatically installed into development and profiling images
|
|
alongside OProfile.
|
|
A configuration option exists within the OProfileUI settings page that you can use to
|
|
enter the location of the <filename>vmlinux</filename> file.
|
|
</para>
|
|
|
|
<para>
|
|
Waiting for debug symbols to transfer from the device can be slow, and it
|
|
is not always necessary to actually have them on the device for OProfile use.
|
|
All that is needed is a copy of the filesystem with the debug symbols present
|
|
on the viewer system.
|
|
The "<link linkend='platdev-gdb-remotedebug-launch-gdb'>Launch GDB on the Host Computer</link>"
|
|
section covers how to create such a directory with
|
|
the <link linkend='source-directory'>Source Directory</link>
|
|
and how to use the OProfileUI Settings Dialog to specify the location.
|
|
If you specify the directory, it will be used when the file checksums
|
|
match those on the system you are profiling.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="platdev-oprofile-oprofileui-offline">
|
|
<title>Offline Mode</title>
|
|
|
|
<para>
|
|
If network access to the target is unavailable, you can generate
|
|
an archive for processing in <filename>oprofile-viewer</filename> as follows:
|
|
<literallayout class='monospaced'>
|
|
# opcontrol --reset
|
|
# opcontrol --start --separate=lib --no-vmlinux -c 5
|
|
.
|
|
.
|
|
[do whatever is being profiled]
|
|
.
|
|
.
|
|
# opcontrol --stop
|
|
# oparchive -o my_archive
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>
|
|
In the above example, <filename>my_archive</filename> is the name of the
|
|
archive directory where you would like the profile archive to be kept.
|
|
After the directory is created, you can copy it to another host and load it
|
|
using <filename>oprofile-viewer</filename> open functionality.
|
|
If necessary, the archive is converted.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='maintaining-open-source-license-compliance-during-your-products-lifecycle'>
|
|
<title>Maintaining Open Source License Compliance During Your Product's Lifecycle</title>
|
|
|
|
<para>
|
|
One of the concerns for a development organization using open source
|
|
software is how to maintain compliance with various open source
|
|
licensing during the lifecycle of the product.
|
|
While this section does not provide legal advice or
|
|
comprehensively cover all scenarios, it does
|
|
present methods that you can use to
|
|
assist you in meeting the compliance requirements during a software
|
|
release.
|
|
</para>
|
|
|
|
<para>
|
|
With hundreds of different open source licenses that the Yocto
|
|
Project tracks, it is difficult to know the requirements of each
|
|
and every license.
|
|
However, we can begin to cover the requirements of the major FLOSS licenses, by
|
|
assuming that there are three main areas of concern:
|
|
<itemizedlist>
|
|
<listitem><para>Source code must be provided.</para></listitem>
|
|
<listitem><para>License text for the software must be
|
|
provided.</para></listitem>
|
|
<listitem><para>Compilation scripts and modifications to the
|
|
source code must be provided.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
There are other requirements beyond the scope of these
|
|
three and the methods described in this section
|
|
(e.g. the mechanism through which source code is distributed).
|
|
</para>
|
|
|
|
<para>
|
|
As different organizations have different methods of complying with
|
|
open source licensing, this section is not meant to imply that
|
|
there is only one single way to meet your compliance obligations,
|
|
but rather to describe one method of achieving compliance.
|
|
The remainder of this section describes methods supported to meet the
|
|
previously mentioned three requirements.
|
|
Once you take steps to meet these requirements,
|
|
and prior to releasing images, sources, and the build system,
|
|
you should audit all artifacts to ensure completeness.
|
|
<note>
|
|
The Yocto Project generates a license manifest during
|
|
image creation that is located
|
|
in <filename>${DEPLOY_DIR}/licenses/<image_name-datestamp></filename>
|
|
to assist with any audits.
|
|
</note>
|
|
</para>
|
|
|
|
<section id='providing-the-source-code'>
|
|
<title>Providing the Source Code</title>
|
|
|
|
<para>
|
|
Compliance activities should begin before you generate the
|
|
final image.
|
|
The first thing you should look at is the requirement that
|
|
tops the list for most compliance groups - providing
|
|
the source.
|
|
The Yocto Project has a few ways of meeting this
|
|
requirement.
|
|
</para>
|
|
|
|
<para>
|
|
One of the easiest ways to meet this requirement is
|
|
to provide the entire
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DL_DIR'><filename>DL_DIR</filename></ulink>
|
|
used by the build.
|
|
This method, however, has a few issues.
|
|
The most obvious is the size of the directory since it includes
|
|
all sources used in the build and not just the source used in
|
|
the released image.
|
|
It will include toolchain source, and other artifacts, which
|
|
you would not generally release.
|
|
However, the more serious issue for most companies is accidental
|
|
release of proprietary software.
|
|
The Yocto Project provides an archiver class to help avoid
|
|
some of these concerns.
|
|
See the
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-archiver'>Archiving Sources - <filename>archive*.bbclass</filename></ulink>"
|
|
section in the Yocto Project Reference Manual for information
|
|
on this class.
|
|
</para>
|
|
|
|
<para>
|
|
Before you employ <filename>DL_DIR</filename> or the
|
|
archiver class, you need to decide how you choose to
|
|
provide source.
|
|
The source archiver class can generate tarballs and SRPMs
|
|
and can create them with various levels of compliance in mind.
|
|
One way of doing this (but certainly not the only way) is to
|
|
release just the original source as a tarball.
|
|
You can do this by adding the following to the
|
|
<filename>local.conf</filename> file found in the
|
|
<link linkend='build-directory'>Build Directory</link>:
|
|
<literallayout class='monospaced'>
|
|
ARCHIVER_MODE ?= "original"
|
|
ARCHIVER_CLASS = "${@'archive-${ARCHIVER_MODE}-source' if
|
|
ARCHIVER_MODE != 'none' else ''}"
|
|
INHERIT += "${ARCHIVER_CLASS}"
|
|
SOURCE_ARCHIVE_PACKAGE_TYPE = "tar"
|
|
</literallayout>
|
|
During the creation of your image, the source from all
|
|
recipes that deploy packages to the image is placed within
|
|
subdirectories of
|
|
<filename>DEPLOY_DIR/sources</filename> based on the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-LICENSE'><filename>LICENSE</filename></ulink>
|
|
for each recipe.
|
|
Releasing the entire directory enables you to comply with
|
|
requirements concerning providing the unmodified source.
|
|
It is important to note that the size of the directory can
|
|
get large.
|
|
</para>
|
|
|
|
<para>
|
|
A way to help mitigate the size issue is to only release
|
|
tarballs for licenses that require the release of
|
|
source.
|
|
Let's assume you are only concerned with GPL code as
|
|
identified with the following:
|
|
<literallayout class='monospaced'>
|
|
$ cd poky/build/tmp/deploy/sources
|
|
$ mkdir ~/gpl_source_release
|
|
$ for dir in */*GPL*; do cp -r $dir ~/gpl_source_release; done
|
|
</literallayout>
|
|
At this point, you could create a tarball from the
|
|
<filename>gpl_source_release</filename> directory and
|
|
provide that to the end user.
|
|
This method would be a step toward achieving compliance
|
|
with section 3a of GPLv2 and with section 6 of GPLv3.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='providing-license-text'>
|
|
<title>Providing License Text</title>
|
|
|
|
<para>
|
|
One requirement that is often overlooked is inclusion
|
|
of license text.
|
|
This requirement also needs to be dealt with prior to
|
|
generating the final image.
|
|
Some licenses require the license text to accompany
|
|
the binary.
|
|
You can achieve this by adding the following to your
|
|
<filename>local.conf</filename> file:
|
|
<literallayout class='monospaced'>
|
|
COPY_LIC_MANIFEST = "1"
|
|
COPY_LIC_DIRS = "1"
|
|
</literallayout>
|
|
Adding these statements to the configuration file ensures
|
|
that the licenses collected during package generation
|
|
are included on your image.
|
|
As the source archiver has already archived the original
|
|
unmodified source that contains the license files,
|
|
you would have already met the requirements for inclusion
|
|
of the license information with source as defined by the GPL
|
|
and other open source licenses.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='providing-compilation-scripts-and-source-code-modifications'>
|
|
<title>Providing Compilation Scripts and Source Code Modifications</title>
|
|
|
|
<para>
|
|
At this point, we have addressed all we need to address
|
|
prior to generating the image.
|
|
The next two requirements are addressed during the final
|
|
packaging of the release.
|
|
</para>
|
|
|
|
<para>
|
|
By releasing the version of the OpenEmbedded build system
|
|
and the layers used during the build, you will be providing both
|
|
compilation scripts and the source code modifications in one
|
|
step.
|
|
</para>
|
|
|
|
<para>
|
|
If the deployment team has a
|
|
<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-layers'>BSP layer</ulink>
|
|
and a distro layer, and those those layers are used to patch,
|
|
compile, package, or modify (in any way) any open source
|
|
software included in your released images, you
|
|
may be required to to release those layers under section 3 of
|
|
GPLv2 or section 1 of GPLv3.
|
|
One way of doing that is with a clean
|
|
checkout of the version of the Yocto Project and layers used
|
|
during your build.
|
|
Here is an example:
|
|
<literallayout class='monospaced'>
|
|
# We built using the &DISTRO_NAME; branch of the poky repo
|
|
$ git clone -b &DISTRO_NAME; git://git.yoctoproject.org/poky
|
|
$ cd poky
|
|
# We built using the release_branch for our layers
|
|
$ git clone -b release_branch git://git.mycompany.com/meta-my-bsp-layer
|
|
$ git clone -b release_branch git://git.mycompany.com/meta-my-software-layer
|
|
# clean up the .git repos
|
|
$ find . -name ".git" -type d -exec rm -rf {} \;
|
|
</literallayout>
|
|
One thing a development organization might want to consider
|
|
for end-user convenience is to modify
|
|
<filename>meta-yocto/conf/bblayers.conf.sample</filename> to
|
|
ensure that when the end user utilizes the released build
|
|
system to build an image, the development organization's
|
|
layers are included in the <filename>bblayers.conf</filename>
|
|
file automatically:
|
|
<literallayout class='monospaced'>
|
|
# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
|
|
# changes incompatibly
|
|
LCONF_VERSION = "6"
|
|
|
|
BBPATH = "${TOPDIR}"
|
|
BBFILES ?= ""
|
|
|
|
BBLAYERS ?= " \
|
|
##OEROOT##/meta \
|
|
##OEROOT##/meta-yocto \
|
|
##OEROOT##/meta-yocto-bsp \
|
|
##OEROOT##/meta-mylayer \
|
|
"
|
|
|
|
BBLAYERS_NON_REMOVABLE ?= " \
|
|
##OEROOT##/meta \
|
|
##OEROOT##/meta-yocto \
|
|
"
|
|
</literallayout>
|
|
Creating and providing an archive of the
|
|
<link linkend='metadata'>Metadata</link> layers
|
|
(recipes, configuration files, and so forth)
|
|
enables you to meet your
|
|
requirements to include the scripts to control compilation
|
|
as well as any modifications to the original source.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
</chapter>
|
|
|
|
<!--
|
|
vim: expandtab tw=80 ts=4
|
|
-->
|