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<!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='dev-manual-model'>
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<title>Common Development Models</title>
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2011-07-27 19:47:59 +00:00
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<para>
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Many development models exist for which you can use the Yocto Project.
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However, for the purposes of this manual we are going to focus on two common models:
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System Development and User Application Development.
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System Development covers Board Support Package (BSP) development and kernel modification
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or configuration.
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User Application Development covers development of applications that you intend to run on some
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target hardware.
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</para>
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<para>
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This chapter presents overviews of both system and application models.
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If you want to examine specific examples of the system development models,
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see the "<link linkend='dev-manual-bsp-appendix'>BSP Development Example</link>"
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appendix and the
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"<link linkend='dev-manual-kernel-appendix'>Kernel Modification Example</link>" appendix.
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For a user-space application development example that uses the
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<trademark class='trade'>Eclipse</trademark> IDE,
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see the
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<ulink url='&YOCTO_DOCS_ADT_URL;'>
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The Yocto Project Application Development Toolkit (ADT) User's Guide</ulink>.
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</para>
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<para>
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Aside from these two models, this chapter will also briefly introduce and discuss
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development using
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<ulink url='&YOCTO_HOME_URL;/projects/hob'>Hob</ulink>, which is a graphical interface
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to the Yocto Project build system.
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</para>
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<section id='system-development-model'>
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<title>System Development Workflow</title>
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<para>
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System development involves modification or creation of an image that you want to run on
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a specific hardware target.
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Usually, when you want to create an image that runs on embedded hardware, the image does
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not require the same number of features that a full-fledged Linux distribution provides.
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Thus, you can create a much smaller image that is designed to use only the hardware
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features for your particular hardware.
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</para>
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<para>
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To help you understand how system development works in the Yocto Project, this section
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covers two types of image development: BSP creation and kernel modification or
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configuration.
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</para>
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<section id='developing-a-board-support-package-bsp'>
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<title>Developing a Board Support Package (BSP)</title>
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<para>
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A BSP is a package of recipes that, when applied, during a build results in
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an image that you can run on a particular board.
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Thus, the package, when compiled into the new image, supports the operation of the board.
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</para>
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<note>
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For a brief list of terms used when describing the development process in the Yocto Project,
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see the "<link linkend='yocto-project-terms'>Yocto Project Terms</link>" section.
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</note>
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<para>
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The remainder of this section presents the basic steps used to create a BSP
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based on an existing BSP that ships with the Yocto Project.
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You can reference the "<link linkend='dev-manual-bsp-appendix'>BSP Development Example</link>"
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appendix for a detailed example that uses the Crown Bay BSP as a base BSP from which to start.
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</para>
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<para>
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The following illustration and list summarize the BSP creation general workflow.
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</para>
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<para>
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<imagedata fileref="figures/bsp-dev-flow.png" width="6in" depth="7in" align="center" scalefit="1" />
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</para>
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<para>
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<orderedlist>
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<listitem><para><emphasis>Set up your host development system to support
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development using the Yocto Project</emphasis>: See the
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"<ulink url='&YOCTO_DOCS_QS_URL;#the-linux-distro'>The Linux Distributions</ulink>"
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and the
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"<ulink url='&YOCTO_DOCS_QS_URL;#packages'>The Packages</ulink>" sections both
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in the Yocto Project Quick Start for requirements.</para></listitem>
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<listitem><para><emphasis>Establish a local copy of the Yocto Project files on your
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system</emphasis>: You need to have the Yocto Project files available on your host system.
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Having the Yocto Project files on your system gives you access to the build
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process and to the tools you need.
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For information on how to get these files, see the
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"<link linkend='getting-setup'>Getting Setup</link>" section.</para></listitem>
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<listitem><para><emphasis>Establish a local copy of the base BSP files</emphasis>: Having
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the BSP files on your system gives you access to the build
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process and to the tools you need for creating a BSP.
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For information on how to get these files, see the
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"<link linkend='getting-setup'>Getting Setup</link>" section.</para></listitem>
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<listitem><para><emphasis>Choose a Yocto Project-supported BSP as your base BSP</emphasis>:
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The Yocto Project ships with several BSPs that support various hardware.
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It is best to base your new BSP on an existing BSP rather than create all the
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recipes and configuration files from scratch.
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While it is possible to create everything from scratch, basing your new BSP
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on something that is close is much easier.
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Or, at a minimum, leveraging off an existing BSP
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gives you some structure with which to start.</para>
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<para>At this point you need to understand your target hardware well enough to determine which
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existing BSP it most closely matches.
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Things to consider are your hardware’s on-board features, such as CPU type and graphics support.
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You should look at the README files for supported BSPs to get an idea of which one
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you could use.
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A generic <trademark class='registered'>Intel</trademark>
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<trademark class='trade'>Atom</trademark>-based BSP to consider is the
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Crown Bay that does not support the <trademark class='registered'>Intel</trademark>
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Embedded Media Graphics Driver (EMGD).
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The remainder of this example uses that base BSP.</para>
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<para>To see the supported BSPs, go to the
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<ulink url='&YOCTO_HOME_URL;/download'>Download</ulink> page on the Yocto Project
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website and click on “BSP Downloads.”</para></listitem>
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<listitem><para><emphasis>Create your own BSP layer</emphasis>: Layers are ideal for
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isolating and storing work for a given piece of hardware.
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A layer is really just a location or area in which you place the recipes for your BSP.
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In fact, a BSP is, in itself, a special type of layer.
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</para>
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<para>
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Another example that illustrates a layer is an application.
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Suppose you are creating an application that has library or other dependencies in
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order for it to compile and run.
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The layer, in this case, would be where all the recipes that define those dependencies
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are kept.
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The key point for a layer is that it is an isolated area that contains
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all the relevant information for the project that the Yocto Project build
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system knows about.
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For more information on layers, see the
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"<link linkend='understanding-and-creating-layers'>Understanding and Creating Layers</link>"
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section.
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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>" section in the
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Yocto Project Board Support Package (BSP) Developer's Guide.</para>
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<note>The Yocto Project supports four BSPs that are part of the
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Yocto Project release: <filename>atom-pc</filename>, <filename>beagleboard</filename>,
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<filename>mpc8315e</filename>, and <filename>routerstationpro</filename>.
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The recipes and configurations for these four BSPs are located and dispersed
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within the <link linkend='yocto-project-files'>Yocto Project Files</link>.
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On the other hand, BSP layers for Crown Bay, Emenlow, Jasper Forest,
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N450, Cedar Trail, Fish River, Fish River Island II, Romley, sys940x, tlk,
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and Sugar Bay exist in their own separate layers within the larger
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<filename>meta-intel</filename> layer.</note>
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<para>When you set up a layer for a new BSP, you should follow a standard layout.
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This layout is described in the section
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"<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-filelayout'>Example Filesystem Layout</ulink>"
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section of the Board Support Package (BSP) Development Guide.
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In the standard layout, you will notice a suggested structure for recipes and
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configuration information.
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You can see the standard layout for the Crown Bay BSP in this example by examining the
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directory structure of the <filename>meta-crownbay</filename> layer inside the
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local Yocto Project files.</para></listitem>
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<listitem><para><emphasis>Make configuration changes to your new BSP
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layer</emphasis>: The standard BSP layer structure organizes the files you need
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to edit in <filename>conf</filename> and several <filename>recipes-*</filename>
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directories within the BSP layer.
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Configuration changes identify where your new layer is on the local system
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and identify which kernel you are going to use.
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</para></listitem>
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<listitem><para><emphasis>Make recipe changes to your new BSP layer</emphasis>: Recipe
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changes include altering recipes (<filename>.bb</filename> files), removing
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recipes you don't use, and adding new recipes that you need to support your hardware.
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</para></listitem>
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<listitem><para><emphasis>Prepare for the build</emphasis>: Once you have made all the
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changes to your BSP layer, there remains a few things
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you need to do for the Yocto Project build system in order for it to create your image.
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You need to get the build environment ready by sourcing an environment setup script
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and you need to be sure two key configuration files are configured appropriately.</para>
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<para>The entire process for building an image is overviewed in the section
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"<ulink url='&YOCTO_DOCS_QS_URL;#building-image'>Building an Image</ulink>" section
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of the Yocto Project Quick Start.
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You might want to reference this information.</para></listitem>
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<listitem><para><emphasis>Build the image</emphasis>: The Yocto Project uses the BitBake
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tool to build images based on the type of image you want to create.
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You can find more information on BitBake
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<ulink url='http://bitbake.berlios.de/manual/'>here</ulink>.</para>
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<para>The build process supports several types of images to satisfy different needs.
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See the
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"<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Reference: Images</ulink>" appendix
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in The Yocto Project Reference Manual for information on
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supported images.</para></listitem>
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</orderedlist>
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</para>
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<para>
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You can view a video presentation on "Building Custom Embedded Images with Yocto"
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at <ulink url='http://free-electrons.com/blog/elc-2011-videos'>Free Electrons</ulink>.
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You can also find supplemental information in
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<ulink url='&YOCTO_DOCS_BSP_URL;'>
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The Board Support Package (BSP) Development Guide</ulink>.
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Finally, there is wiki page write up of the example also located
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<ulink url='&YOCTO_WIKI_URL;/wiki/Transcript:_creating_one_generic_Atom_BSP_from_another'>
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here</ulink> that you might find helpful.
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</para>
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</section>
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2011-07-28 13:21:28 +00:00
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<section id='modifying-the-kernel'>
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<title><anchor id='kernel-spot' />Modifying the Kernel</title>
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<para>
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Kernel modification involves changing the Linux Yocto kernel, which could involve changing
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configuration options as well as adding new kernel recipes.
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Configuration changes can be added in the form of configuration fragments, while recipe
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modification comes through the kernel's <filename>recipes-kernel</filename> area
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in a kernel layer you create.
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</para>
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<para>
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|
|
|
The remainder of this section presents a high-level overview of the Linux Yocto
|
|
|
|
|
kernel architecture and the steps to modify the Linux Yocto kernel.
|
2011-08-31 13:46:23 +00:00
|
|
|
|
For a complete discussion of the kernel, see
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_DOCS_KERNEL_URL;'>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
The Yocto Project Kernel Architecture and Use Manual</ulink>.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
You can reference the appendix
|
|
|
|
|
"<link linkend='dev-manual-kernel-appendix'>Kernel Modification Example</link>"
|
2011-08-01 21:39:35 +00:00
|
|
|
|
for a detailed example that changes the configuration of a kernel.
|
2011-07-27 19:10:25 +00:00
|
|
|
|
</para>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
|
|
|
|
|
<section id='kernel-overview'>
|
|
|
|
|
<title>Kernel Overview</title>
|
|
|
|
|
|
|
|
|
|
<para>
|
2011-10-20 17:38:05 +00:00
|
|
|
|
Traditionally, when one thinks of a patched kernel, they think of a base kernel
|
2011-11-02 20:37:32 +00:00
|
|
|
|
source tree and a fixed structure that contains kernel patches.
|
|
|
|
|
The Yocto Project, however, employs mechanisms, that in a sense, result in a kernel source
|
2011-08-01 21:39:35 +00:00
|
|
|
|
generator.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
By the end of this section, this analogy will become clearer.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
You can find a web interface to the Linux Yocto kernel source repositories at
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_GIT_URL;'></ulink>.
|
2011-08-31 13:46:23 +00:00
|
|
|
|
If you look at the interface, you will see to the left a grouping of
|
|
|
|
|
Git repositories titled "Yocto Linux Kernel."
|
2012-04-26 14:03:39 +00:00
|
|
|
|
Within this group, you will find several kernels supported by
|
2011-08-31 13:46:23 +00:00
|
|
|
|
the Yocto Project:
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-2.6.34</filename></emphasis> - The
|
|
|
|
|
stable Linux Yocto kernel that is based on the Linux 2.6.34 release.</para></listitem>
|
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-2.6.37</filename></emphasis> - The
|
|
|
|
|
stable Linux Yocto kernel that is based on the Linux 2.6.37 release.</para></listitem>
|
2012-02-02 20:40:01 +00:00
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-3.0</filename></emphasis> - The stable
|
2011-08-31 13:46:23 +00:00
|
|
|
|
Linux Yocto kernel that is based on the Linux 3.0 release.</para></listitem>
|
2012-02-02 20:40:01 +00:00
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-3.0-1.1.x</filename></emphasis> - The
|
|
|
|
|
stable Linux Yocto kernel to use with the Yocto Project Release 1.1.x. This kernel
|
|
|
|
|
is based on the Linux 3.0 release</para></listitem>
|
2012-04-23 20:41:10 +00:00
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-3.2</filename></emphasis> - The
|
|
|
|
|
stable Linux Yocto kernel to use with the Yocto Project Release 1.2. This kernel
|
|
|
|
|
is based on the Linux 3.2 release</para></listitem>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
<listitem><para><emphasis><filename>linux-yocto-dev</filename></emphasis> - A development
|
|
|
|
|
kernel based on the latest upstream release candidate available.</para></listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
2011-10-20 17:38:05 +00:00
|
|
|
|
The kernels are maintained using the Git revision control system
|
|
|
|
|
that structures them using the familiar "tree", "branch", and "leaf" scheme.
|
2011-08-31 13:46:23 +00:00
|
|
|
|
Branches represent diversions from general code to more specific code, while leaves
|
|
|
|
|
represent the end-points for a complete and unique kernel whose source files
|
|
|
|
|
when gathered from the root of the tree to the leaf accumulate to create the files
|
|
|
|
|
necessary for a specific piece of hardware and its features.
|
|
|
|
|
The following figure displays this concept:
|
|
|
|
|
<para>
|
|
|
|
|
<imagedata fileref="figures/kernel-overview-1.png"
|
|
|
|
|
width="6in" depth="6in" align="center" scale="100" />
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
Within the figure, the "Kernel.org Branch Point" represents the point in the tree
|
2011-10-20 17:38:05 +00:00
|
|
|
|
where a supported base kernel is modified from the Linux kernel.
|
2011-08-31 13:46:23 +00:00
|
|
|
|
For example, this could be the branch point for the <filename>linux-yocto-3.0</filename>
|
|
|
|
|
kernel.
|
|
|
|
|
Thus, everything further to the right in the structure is based on the
|
|
|
|
|
<filename>linux-yocto-3.0</filename> kernel.
|
|
|
|
|
Branch points to right in the figure represent where the
|
|
|
|
|
<filename>linux-yocto-3.0</filename> kernel is modified for specific hardware
|
|
|
|
|
or types of kernels, such as real-time kernels.
|
|
|
|
|
Each leaf thus represents the end-point for a kernel designed to run on a specific
|
|
|
|
|
targeted device.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
|
2011-08-01 21:39:35 +00:00
|
|
|
|
<para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
The overall result is a Git-maintained repository from which all the supported
|
2011-10-20 17:38:05 +00:00
|
|
|
|
Yocto Project kernel types can be derived for all the supported Yocto Project devices.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
A big advantage to this scheme is the sharing of common features by keeping them in
|
2011-08-31 13:46:23 +00:00
|
|
|
|
"larger" branches within the tree.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
This practice eliminates redundant storage of similar features shared among kernels.
|
|
|
|
|
</para>
|
|
|
|
|
|
2011-08-31 13:46:23 +00:00
|
|
|
|
<note>
|
2012-04-26 14:07:31 +00:00
|
|
|
|
Keep in mind the figure does not take into account all the supported Linux Yocto
|
2011-08-31 13:46:23 +00:00
|
|
|
|
kernel types, but rather shows a single generic kernel just for conceptual purposes.
|
|
|
|
|
Also keep in mind that this structure represents the Yocto Project source repositories
|
|
|
|
|
that are either pulled from during the build or established on the host development system
|
|
|
|
|
prior to the build by either cloning a particular kernel's Git repository or by
|
|
|
|
|
downloading and unpacking a tarball.
|
|
|
|
|
</note>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
Storage of all the available kernel source code is one thing, while representing the
|
|
|
|
|
code on your host development system is another.
|
|
|
|
|
Conceptually, you can think of the Yocto Project kernel source repositories as all the
|
|
|
|
|
source files necessary for all the supported kernels.
|
|
|
|
|
As a developer, you are just interested in the source files for the kernel on
|
|
|
|
|
on which you are working.
|
|
|
|
|
And, furthermore, you need them available on your host system.
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
You make kernel source code available on your host development system by using
|
|
|
|
|
Git to create a bare clone of the Linux Yocto kernel Git repository
|
|
|
|
|
in which you are interested.
|
|
|
|
|
Then, you use Git again to clone a copy of that bare clone.
|
|
|
|
|
This copy represents the directory structure on your host system that is particular
|
|
|
|
|
to the kernel you want.
|
|
|
|
|
These are the files you actually modify to change the kernel.
|
|
|
|
|
See the <link linkend='local-kernel-files'>Linux Yocto Kernel</link> item earlier
|
|
|
|
|
in this manual for an example of how to set up the kernel source directory
|
|
|
|
|
structure on your host system.
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
This next figure illustrates how the kernel source files might be arranged on
|
|
|
|
|
your host system.
|
|
|
|
|
</para>
|
|
|
|
|
|
2011-08-01 21:39:35 +00:00
|
|
|
|
<para>
|
2012-04-26 14:46:36 +00:00
|
|
|
|
<imagedata fileref="figures/kernel-overview-3-denzil.png"
|
2011-08-31 13:46:23 +00:00
|
|
|
|
width="6in" depth="4in" align="center" scale="100" />
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
In the previous figure, the file structure on the left represents the bare clone
|
|
|
|
|
set up to track the Yocto Project kernel Git repository.
|
|
|
|
|
The structure on the right represents the copy of the bare clone.
|
|
|
|
|
When you make modifcations to the kernel source code, this is the area in which
|
|
|
|
|
you work.
|
|
|
|
|
Once you make corrections, you must use Git to push the committed changes to the
|
|
|
|
|
bare clone.
|
|
|
|
|
The example in <xref linkend='modifying-the-kernel-source-code'>
|
|
|
|
|
Modifying the Kernel Source Code</xref> provides a detailed example.
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
What happens during the build?
|
2011-08-01 21:39:35 +00:00
|
|
|
|
When you build the kernel on your development system all files needed for the build
|
|
|
|
|
are taken from the Yocto Project source repositories pointed to by the
|
|
|
|
|
<filename>SRC_URI</filename> variable and gathered in a temporary work area
|
|
|
|
|
where they are subsequently used to create the unique kernel.
|
|
|
|
|
Thus, in a sense, the process constructs a local source tree specific to your
|
|
|
|
|
kernel to generate the new kernel image - a source generator if you will.
|
|
|
|
|
</para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
The following figure shows the temporary file structure
|
|
|
|
|
created on your host system when the build occurs.
|
|
|
|
|
This build directory contains all the source files used during the build.
|
2011-08-02 20:00:48 +00:00
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
<imagedata fileref="figures/kernel-overview-2.png"
|
|
|
|
|
width="6in" depth="5in" align="center" scale="100" />
|
|
|
|
|
</para>
|
2011-08-02 14:48:52 +00:00
|
|
|
|
|
2011-08-01 21:39:35 +00:00
|
|
|
|
<para>
|
2011-08-31 13:46:23 +00:00
|
|
|
|
Again, for a complete discussion of the Yocto Project kernel's architcture and its
|
|
|
|
|
branching strategy,
|
2012-04-26 15:05:38 +00:00
|
|
|
|
see <ulink url='&YOCTO_DOCS_KERNEL_URL;'>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
The Yocto Project Kernel Architecture and Use Manual</ulink>.
|
2012-04-26 15:05:38 +00:00
|
|
|
|
You can also reference the
|
|
|
|
|
"<link linkend='modifying-the-kernel-source-code'>Modifying the Kernel Source Code</link>"
|
|
|
|
|
section for a detailed example that modifies the kernel.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</para>
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
<section id='kernel-modification-workflow'>
|
|
|
|
|
<title>Kernel Modification Workflow</title>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
This illustration and the following list summarizes the kernel modification general workflow.
|
|
|
|
|
</para>
|
|
|
|
|
|
2011-08-11 17:18:38 +00:00
|
|
|
|
<para>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<imagedata fileref="figures/kernel-dev-flow.png"
|
|
|
|
|
width="6in" depth="7.5in" align="center" scalefit="1" />
|
2011-08-11 17:18:38 +00:00
|
|
|
|
</para>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem><para><emphasis>Set up your host development system to support
|
|
|
|
|
development using the Yocto Project</emphasis>: See
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#the-linux-distro'>The Linux Distributions</ulink>" and
|
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#packages'>The Packages</ulink>" sections both
|
2011-08-02 20:00:48 +00:00
|
|
|
|
in the Yocto Project Quick Start for requirements.</para></listitem>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
<listitem><para><emphasis>Establish a local copy of the Yocto Project files on your
|
2011-08-02 14:48:52 +00:00
|
|
|
|
system</emphasis>: Having the Yocto Project files on your system gives you access to
|
|
|
|
|
the build process and tools you need.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
For information on how to get these files, see the bulleted item
|
2011-09-20 17:26:58 +00:00
|
|
|
|
"<link linkend='local-yp-release'>Yocto Project Release</link>" earlier in this manual.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</para></listitem>
|
2011-08-11 14:20:45 +00:00
|
|
|
|
<listitem><para><emphasis>Set up the <filename>poky-extras</filename> Git
|
2011-08-10 23:27:45 +00:00
|
|
|
|
repository</emphasis>: This repository is the area for your configuration
|
|
|
|
|
fragments, new kernel recipes, and the kernel <filename>.bbappend</filename>
|
|
|
|
|
file used during the build.
|
|
|
|
|
It is good practice to set this repository up inside the local Yocto
|
|
|
|
|
Project files Git repository.
|
2011-08-02 20:00:48 +00:00
|
|
|
|
For information on how to get these files, see the bulleted item
|
2011-09-20 17:26:58 +00:00
|
|
|
|
"<link linkend='poky-extras-repo'>The <filename>poky-extras</filename> Git Repository</link>"
|
2011-10-20 17:38:05 +00:00
|
|
|
|
earlier in this manual.
|
|
|
|
|
<note>While it is certainly possible to modify the kernel without involving
|
|
|
|
|
a local Git repository, the suggested workflow for kernel modification
|
|
|
|
|
using the Yocto Project does use a Git repository.</note></para></listitem>
|
2011-08-10 23:27:45 +00:00
|
|
|
|
<listitem><para><emphasis>Establish a local copy of the Linux Yocto kernel files on your
|
|
|
|
|
system</emphasis>: In order to make modifications to the kernel you need two things:
|
2011-09-20 17:26:58 +00:00
|
|
|
|
a bare clone of the Linux Yocto kernel you are modifying and
|
|
|
|
|
a copy of that bare clone.
|
2011-08-10 23:27:45 +00:00
|
|
|
|
The bare clone is required by the build process and is the area to which you
|
2011-09-20 17:26:58 +00:00
|
|
|
|
push your kernel source changes (pulling does not work with bare clones).
|
2011-08-10 23:27:45 +00:00
|
|
|
|
The copy of the bare clone is a local Git repository that contains all the kernel's
|
|
|
|
|
source files.
|
|
|
|
|
You make your changes to the files in this copy of the bare clone.
|
|
|
|
|
For information on how to set these two items up, see the bulleted item
|
2011-09-20 17:26:58 +00:00
|
|
|
|
"<link linkend='local-kernel-files'>Linux Yocto Kernel</link>"
|
|
|
|
|
earlier in this manual.</para></listitem>
|
2011-08-10 23:27:45 +00:00
|
|
|
|
<listitem><para><emphasis>Make changes to the kernel source code if
|
|
|
|
|
applicable</emphasis>: Modifying the kernel does not always mean directly
|
|
|
|
|
changing source files.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
However, if you have to do this, you make the changes in the local
|
2011-08-10 23:27:45 +00:00
|
|
|
|
Git repository you set up to hold the source files (i.e. the copy of the
|
|
|
|
|
bare clone).
|
2011-09-20 17:26:58 +00:00
|
|
|
|
Once the changes are made, you need to use Git commands to commit the changes
|
2011-08-10 23:27:45 +00:00
|
|
|
|
and then push them to the bare clone.</para></listitem>
|
2011-08-02 14:48:52 +00:00
|
|
|
|
<listitem><para><emphasis>Make kernel configuration changes
|
2011-10-20 17:38:05 +00:00
|
|
|
|
if applicable</emphasis>:
|
2011-09-20 17:26:58 +00:00
|
|
|
|
If your situation calls for changing the kernel's configuration, you can
|
2011-08-10 23:27:45 +00:00
|
|
|
|
use <filename>menuconfig</filename>
|
|
|
|
|
to enable and disable kernel configurations.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
Using <filename>menuconfig</filename> allows you to interactively develop and test the
|
|
|
|
|
configuration changes you are making to the kernel.
|
|
|
|
|
When saved, changes using <filename>menuconfig</filename> update the kernel's
|
|
|
|
|
<filename>.config</filename>.
|
2011-10-20 17:38:05 +00:00
|
|
|
|
Try to resist the temptation of directly editing the <filename>.config</filename>
|
2012-02-22 19:51:35 +00:00
|
|
|
|
file found in the
|
|
|
|
|
<link linkend='yocto-project-build-directory'>Yocto Project Build Directory</link> at
|
2011-10-20 17:38:05 +00:00
|
|
|
|
<filename>tmp/sysroots/<machine-name>/kernel</filename>.
|
|
|
|
|
Doing so, can produce unexpected results when the Yocto Project build system
|
|
|
|
|
regenerates the configuration file.</para>
|
|
|
|
|
<para>Once you are satisfied with the configuration changes made using
|
|
|
|
|
<filename>menuconfig</filename>, you can directly examine the
|
|
|
|
|
<filename>.config</filename> file against a saved original and gather those
|
2012-03-13 22:45:51 +00:00
|
|
|
|
changes into a config fragment to be referenced from within the kernel's
|
|
|
|
|
<filename>.bbappend</filename> file.</para></listitem>
|
2011-10-20 17:38:05 +00:00
|
|
|
|
<listitem><para><emphasis>Add or extend kernel recipes if applicable</emphasis>:
|
|
|
|
|
The standard
|
2011-08-10 23:27:45 +00:00
|
|
|
|
layer structure organizes recipe files inside the
|
|
|
|
|
<filename>meta-kernel-dev</filename> layer that is within the
|
|
|
|
|
<filename>poky-extras</filename> Git repository.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
If you need to add new kernel recipes, you add them within this layer.
|
|
|
|
|
Also within this area, you will find the <filename>.bbappend</filename>
|
2011-08-10 23:27:45 +00:00
|
|
|
|
file that appends information to the kernel's recipe file used during the
|
|
|
|
|
build.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Prepare for the build</emphasis>: Once you have made all the
|
2011-08-10 23:27:45 +00:00
|
|
|
|
changes to your kernel (configurations, source code changes, recipe additions,
|
2011-09-20 17:26:58 +00:00
|
|
|
|
or recipe changes), there remains a few things
|
2012-04-26 15:10:30 +00:00
|
|
|
|
you need to do in order for the Yocto Project build system (BitBake) to create your image.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
If you have not done so, you need to get the build environment ready by sourcing
|
2011-08-02 14:48:52 +00:00
|
|
|
|
the environment setup script described earlier.
|
2011-08-31 14:00:07 +00:00
|
|
|
|
You also need to be sure two key configuration files
|
|
|
|
|
(<filename>local.conf</filename> and <filename>bblayers.conf</filename>)
|
|
|
|
|
are configured appropriately.</para>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
<para>The entire process for building an image is overviewed in the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#building-image'>Building an Image</ulink>"
|
|
|
|
|
section of the Yocto Project Quick Start.
|
2011-08-10 23:27:45 +00:00
|
|
|
|
You might want to reference this information.
|
|
|
|
|
Also, you should look at the detailed examples found in the appendices at
|
2011-09-20 17:26:58 +00:00
|
|
|
|
at the end of this manual.</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Build the image</emphasis>: The Yocto Project
|
|
|
|
|
build system Poky uses the BitBake
|
2011-08-02 14:48:52 +00:00
|
|
|
|
tool to build images based on the type of image you want to create.
|
2011-08-01 21:39:35 +00:00
|
|
|
|
You can find more information on BitBake
|
|
|
|
|
<ulink url='http://bitbake.berlios.de/manual/'>here</ulink>.</para>
|
|
|
|
|
<para>The build process supports several types of images to satisfy different needs.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
See the appendix
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Reference: Images</ulink>" in
|
2012-01-11 16:08:13 +00:00
|
|
|
|
The Yocto Project Reference Manual for information on supported images.</para></listitem>
|
2011-08-02 14:48:52 +00:00
|
|
|
|
<listitem><para><emphasis>Make your configuration changes available
|
2011-09-20 17:26:58 +00:00
|
|
|
|
in the kernel layer</emphasis>: Up to this point, all the configuration changes to the
|
2011-08-01 21:39:35 +00:00
|
|
|
|
kernel have been done and tested iteratively.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
Once they are tested and ready to go, you can move them into the kernel layer,
|
|
|
|
|
which allows you to distribute the layer.</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>If applicable, share your in-tree changes</emphasis>:
|
|
|
|
|
If the changes you made
|
2011-10-20 17:38:05 +00:00
|
|
|
|
are suited for all Linux Yocto users, you might want to send them on for inclusion
|
|
|
|
|
into the Linux Yocto Git repository.
|
|
|
|
|
If the changes are accepted, the Yocto Project Maintainer pulls them into
|
|
|
|
|
the master branch of the kernel tree.
|
2011-09-20 17:26:58 +00:00
|
|
|
|
Doing so makes them available to everyone using the kernel.</para></listitem>
|
2011-08-01 21:39:35 +00:00
|
|
|
|
</orderedlist>
|
|
|
|
|
</para>
|
|
|
|
|
</section>
|
2011-07-27 19:10:25 +00:00
|
|
|
|
</section>
|
2011-07-15 20:17:07 +00:00
|
|
|
|
</section>
|
|
|
|
|
|
2011-07-27 19:47:59 +00:00
|
|
|
|
<section id='place-holder-section-two'>
|
2011-09-20 20:02:34 +00:00
|
|
|
|
<title>Application Development Workflow</title>
|
2011-07-27 19:47:59 +00:00
|
|
|
|
|
|
|
|
|
<para>
|
2011-09-20 20:02:34 +00:00
|
|
|
|
Application development involves creation of an application that you want to be able
|
|
|
|
|
to run on your target hardware, which is running a Linux Yocto image.
|
2011-09-23 15:07:41 +00:00
|
|
|
|
The Yocto Project provides an Application Development Toolkit (ADT) that
|
|
|
|
|
facilitates quick development and integration of your application into its run-time environment.
|
|
|
|
|
Using the ADT you can employ cross-development toolchains designed for your target hardware
|
2011-09-20 20:02:34 +00:00
|
|
|
|
to compile and link your application.
|
2011-09-23 15:07:41 +00:00
|
|
|
|
You can then deploy your application to the actual hardware or to the QEMU emulator for testing.
|
|
|
|
|
If you are familiar with the popular Eclipse IDE, you can use an Eclipse Yocto Plug-in to
|
|
|
|
|
allow you to develop, deploy, and test your application all from within Eclipse.
|
2011-09-20 20:02:34 +00:00
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
While we strongly suggest using the Yocto Project ADT to develop your application, you might
|
|
|
|
|
not want to.
|
|
|
|
|
If this is the case, you can still use pieces of the Yocto Project for your development process.
|
|
|
|
|
However, because the process can vary greatly, this manual does not provide detail on the process.
|
2011-09-20 20:02:34 +00:00
|
|
|
|
</para>
|
|
|
|
|
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<section id='workflow-using-the-adt-and-eclipse'>
|
|
|
|
|
<title>Workflow Using the ADT and <trademark class='trade'>Eclipse</trademark></title>
|
2011-09-20 20:02:34 +00:00
|
|
|
|
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<para>
|
|
|
|
|
To help you understand how application development works in the Yocto Project ADT
|
|
|
|
|
environment, this section
|
|
|
|
|
provides an overview of the general development process.
|
|
|
|
|
If you want to see a detailed example of the process as it is used from within the Eclipse
|
|
|
|
|
IDE, see
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_DOCS_ADT_URL;'>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
The Application Development Toolkit (ADT) User's Manual</ulink>.
|
|
|
|
|
</para>
|
2011-09-20 20:02:34 +00:00
|
|
|
|
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<para>
|
|
|
|
|
This illustration and the following list summarizes the application development general workflow.
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
<imagedata fileref="figures/app-dev-flow.png"
|
|
|
|
|
width="7in" depth="8in" align="center" scale="100" />
|
|
|
|
|
</para>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem><para><emphasis>Prepare the Host System for the Yocto Project</emphasis>:
|
|
|
|
|
See
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#the-linux-distro'>The Linux Distributions</ulink>" and
|
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#packages'>The Packages</ulink>" sections both
|
2011-09-23 15:07:41 +00:00
|
|
|
|
in the Yocto Project Quick Start for requirements.</para></listitem>
|
|
|
|
|
|
|
|
|
|
<!--
|
|
|
|
|
WRITER NOTE: The areas to get the kernel and root filesystem are located in the Index of
|
|
|
|
|
downloads. There are many forms of each. The files that have "rootfs" are just the
|
|
|
|
|
target root filesystems. The file that is very small and starts with bzImage is just
|
|
|
|
|
the kernel image isolated so that it can be written to a special on-board area of
|
|
|
|
|
flash memory. Some systems require this. In the machines directory there are
|
|
|
|
|
files that combine the kernel image and the root filesystem. These files are the ISO
|
|
|
|
|
and HDDIMG files. ISO images are designed to be deployed on a DVD or CD. The ISO
|
|
|
|
|
images are designed to be deployed on a USB stick. There might be some relics in
|
|
|
|
|
the machine directory. For example, there is the "emenlow-bernard-5.0.0.tar.bz2"
|
|
|
|
|
file. Nobody seems to know what this is. If a developer needs the image and the
|
|
|
|
|
root filesystem I think that they want the small kernel image and a matching root
|
|
|
|
|
filesystem. Although, Paul Eggleton says that the HDDIMG types could be used to
|
|
|
|
|
develop on. I am not sure that we can use one of those in the ADT though as they
|
|
|
|
|
want you to point to the kernel image and the target root filesystem. Maybe you
|
|
|
|
|
could just point to the same spot. I am not sure.
|
|
|
|
|
-->
|
|
|
|
|
|
|
|
|
|
<listitem><para><emphasis>Secure the Linux Yocto Kernel Target Image</emphasis>:
|
|
|
|
|
You must have a target kernel image that has been built using the Yocto Project.</para>
|
|
|
|
|
<para>Depending on whether the Yocto Project has a pre-built image that matches your target
|
|
|
|
|
architecture and where you are going to run the image while you develop your application
|
2012-04-26 15:16:52 +00:00
|
|
|
|
(QEMU or real hardware), the area from which you get the image differs.
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem><para>Download the image from
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_MACHINES_DL_URL;'>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<filename>machines</filename></ulink> if your target architecture is supported
|
|
|
|
|
and you are going to develop and test your application on actual hardware.
|
|
|
|
|
</para></listitem>
|
|
|
|
|
<listitem><para>Download the image from the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_QEMU_DL_URL;'>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<filename>machines/qemu</filename></ulink> if your target architecture is supported
|
|
|
|
|
and you are going to develop and test your application using the QEMU
|
|
|
|
|
emulator.</para></listitem>
|
|
|
|
|
<listitem><para>Build your image if you cannot find a pre-built image that matches
|
|
|
|
|
your target architecture.
|
|
|
|
|
If your target architecture is similar to a supported architecture, you can
|
|
|
|
|
modify the kernel image before you build it.
|
|
|
|
|
See the
|
|
|
|
|
"<link linkend='kernel-modification-workflow'>Kernel Modification Workflow</link>"
|
|
|
|
|
section earlier in this manual for information on how to create a modified
|
|
|
|
|
Linux Yocto kernel.</para></listitem>
|
|
|
|
|
</itemizedlist></para>
|
|
|
|
|
<para>For information on pre-built kernel image naming schemes for images
|
|
|
|
|
that can run on the QEMU emulator, see the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_QS_URL;#using-pre-built'>Using Pre-Built Binaries and QEMU</ulink>"
|
|
|
|
|
section in the Yocto Project Quick Start.</para></listitem>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<listitem><para><emphasis>Install the ADT</emphasis>:
|
|
|
|
|
The ADT provides a target-specific cross-development toolchain, the root filesystem,
|
|
|
|
|
the QEMU emulator, and other tools that can help you develop your application.
|
|
|
|
|
While it is possible to get these pieces separately, the Yocto Project provides an
|
|
|
|
|
easy method.
|
|
|
|
|
You can get these pieces by running an ADT installer script, which is configurable.
|
|
|
|
|
For information on how to install the ADT, see the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_ADT_URL;#using-the-adt-installer'>Using the ADT Installer</ulink>"
|
|
|
|
|
section
|
|
|
|
|
in the Yocto Project Application Development (ADT) User's Manual.</para></listitem>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<listitem><para><emphasis>If Applicable, Secure the Target Root Filesystem</emphasis>:
|
|
|
|
|
If you choose not to install the ADT using the ADT Installer,
|
|
|
|
|
you need to find and download the
|
|
|
|
|
appropriate root filesystems.
|
|
|
|
|
You can find these tarballs in the same areas used for the kernel images.
|
|
|
|
|
Depending on the type of image you are running, the root filesystem you need differs.
|
|
|
|
|
For example, if you are developing an application that runs on an image that
|
|
|
|
|
supports Sato, you need to get root filesystem that supports Sato.
|
|
|
|
|
</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Create and Build your Application</emphasis>:
|
|
|
|
|
At this point, you need to have source files for your application.
|
|
|
|
|
Once you have the files, you can use the Eclipse IDE to import them and build the
|
|
|
|
|
project.
|
|
|
|
|
If you are not using Eclipse, you need to use the cross-development tools you have
|
|
|
|
|
installed to create the image.</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Deploy the Image with the Application</emphasis>:
|
|
|
|
|
If you are using the Eclipse IDE, you can deploy your image to the hardware or to
|
|
|
|
|
QEMU through the project's preferences.
|
|
|
|
|
If you are not using the Eclipse IDE, then you need to deploy the application using
|
|
|
|
|
other methods to the hardware.
|
|
|
|
|
Or, if you are using QEMU, you need to use that tool and load your image in for testing.
|
|
|
|
|
</para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Test and Debug the Application</emphasis>:
|
|
|
|
|
Once your application is deployed, you need to test it.
|
|
|
|
|
Within the Eclipse IDE, you can use the debubbing environment along with the
|
|
|
|
|
set of user-space tools installed along with the ADT to debug your application.
|
|
|
|
|
Of course, the same user-space tools are available separately to use if you choose
|
|
|
|
|
not to use the Eclipse IDE.</para></listitem>
|
|
|
|
|
</orderedlist>
|
|
|
|
|
</para>
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
<section id='workflow-without-adt'>
|
|
|
|
|
<title>Workflow Without ADT</title>
|
|
|
|
|
|
|
|
|
|
<para>
|
|
|
|
|
If you want to develop an application outside of the Yocto Project ADT environment, you
|
|
|
|
|
can still employ the cross-development toolchain, the QEMU emulator, and a number of supported
|
|
|
|
|
target image files.
|
|
|
|
|
You just need to follow these general steps:
|
|
|
|
|
<orderedlist>
|
|
|
|
|
<listitem><para><emphasis>Install the cross-development toolchain for your target hardware:</emphasis>
|
|
|
|
|
For information on how to install the toolchain, see the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_ADT_URL;#using-an-existing-toolchain-tarball'>Using a Cross-Toolchain Tarball</ulink>"
|
|
|
|
|
section
|
|
|
|
|
in the Yocto Project Application Development (ADT) User's Manual.</para></listitem>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<listitem><para><emphasis>Download the Target Image:</emphasis> The Yocto Project supports
|
|
|
|
|
several target architectures and has many pre-built kernel images and root filesystem
|
|
|
|
|
images.</para>
|
|
|
|
|
<para>If you are going to develop your application on hardware, go to the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_MACHINES_DL_URL;'>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<filename>machines</filename></ulink> download area and choose a target machine area
|
|
|
|
|
from which to download the kernel image and root filesystem.
|
|
|
|
|
This download area could have several files in it that support development using
|
|
|
|
|
actual hardware.
|
|
|
|
|
For example, the area might contain <filename>.hddimg</filename> files that combine the
|
|
|
|
|
kernel image with the filesystem, boot loaders, etc.
|
|
|
|
|
Be sure to get the files you need for your particular development process.</para>
|
|
|
|
|
<para>If you are going to develop your application and then run and test it using the QEMU
|
|
|
|
|
emulator, go to the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
<ulink url='&YOCTO_QEMU_DL_URL;'>
|
2011-09-23 15:07:41 +00:00
|
|
|
|
<filename>machines/qemu</filename></ulink> download area.
|
|
|
|
|
From this area, go down into the directory for your target architecture
|
|
|
|
|
(e.g. <filename>qemux86_64</filename> for an
|
|
|
|
|
<trademark class='registered'>Intel</trademark>-based 64-bit architecture).
|
|
|
|
|
Download kernel, root filesystem, and any other files you need for your process.
|
|
|
|
|
<note>In order to use the root filesystem in QEMU, you need to extract it.
|
|
|
|
|
See the
|
2012-03-09 19:40:39 +00:00
|
|
|
|
"<ulink url='&YOCTO_DOCS_ADT_URL;#extracting-the-root-filesystem'>Extracting the Root Filesystem</ulink>" section for information on how to extract the
|
2011-09-23 15:07:41 +00:00
|
|
|
|
root filesystem.</note></para></listitem>
|
|
|
|
|
<listitem><para><emphasis>Develop and Test your Application:</emphasis> At this point,
|
|
|
|
|
you have the tools to develop your application.
|
|
|
|
|
If you need to separately install and use the QEMU emulator, you can go to
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<ulink url='http://www.qemu.org'>QEMU Home Page</ulink> to download and learn about the
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emulator.</para></listitem>
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</orderedlist>
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</para>
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</section>
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2011-07-27 19:47:59 +00:00
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</section>
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2012-03-22 21:01:11 +00:00
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<section id='image-development-using-hob'>
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<title>Image Development Using Hob</title>
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2012-03-22 22:41:26 +00:00
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<para>
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The <ulink url='&YOCTO_HOME_URL;/projects/hob'>Hob</ulink> is a graphical user interface for the Yocto
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Project build system based on BitBake.
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You can use the Hob to build custom operating system images within the Yocto Project build environment.
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Hob simply provides a friendly interface over the build system used during system development.
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In other words, building images with the Hob lets you take care of common Yocto Project build tasks more easily.
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</para>
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<para>
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For a better understanding of Hob, see the project page at
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<ulink url='&YOCTO_HOME_URL;/projects/hob'></ulink> on the Yocto Project website.
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The page has a short introductory training video on Hob.
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The following lists some features of Hob:
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<itemizedlist>
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<listitem><para>You can setup and run Hob using these commands:
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<literallayout class='monospaced'>
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$ source oe-init-build-env
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$ hob
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</literallayout></para></listitem>
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<listitem><para>You can set the
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<ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'><filename>MACHINE</filename></ulink>
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for which you are building the image.</para></listitem>
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<listitem><para>You can modify various policy settings such as the package format used to build with,
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the parrallelism BitBake uses, whether or not to build an external toolchain, and which host
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to build against.</para></listitem>
|
2012-04-26 15:29:21 +00:00
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<listitem><para>You can manage
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<link linkend='understanding-and-creating-layers'>layers</link>.</para></listitem>
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2012-03-22 22:41:26 +00:00
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<listitem><para>You can select a base image and then add extra packages for your custom build.
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</para></listitem>
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<listitem><para>You can launch and monitor the build from within Hob.</para></listitem>
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</itemizedlist>
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</para>
|
2012-03-22 21:01:11 +00:00
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</section>
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2011-07-15 19:54:29 +00:00
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</chapter>
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<!--
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vim: expandtab tw=80 ts=4
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-->
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