1633 lines
89 KiB
XML
1633 lines
89 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='sdk-extensible'>
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<title>Using the Extensible SDK</title>
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<para>
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This chapter describes the extensible SDK and how to install it.
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Information covers the pieces of the SDK, how to install it, and
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presents a look at using the <filename>devtool</filename>
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functionality.
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The extensible SDK makes it easy to add new applications and libraries
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to an image, modify the source for an existing component, test
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changes on the target hardware, and ease integration into the rest of
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the
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<ulink url='&YOCTO_DOCS_DEV_URL;#build-system-term'>OpenEmbedded build system</ulink>.
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<note>
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For a side-by-side comparison of main features supported for an
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extensible SDK as compared to a standard SDK, see the
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"<link linkend='sdk-manual-intro'>Introduction</link>"
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section.
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</note>
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</para>
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<para>
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In addition to the functionality available through
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<filename>devtool</filename>, you can alternatively make use of the
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toolchain directly, for example from Makefile, Autotools, and
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Eclipse-based projects.
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See the
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"<link linkend='sdk-working-projects'>Using the SDK Toolchain Directly</link>"
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chapter for more information.
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</para>
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<section id='sdk-extensible-sdk-intro'>
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<title>Why use the Extensible SDK and What is in It?</title>
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<para>
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The extensible SDK provides a cross-development toolchain and
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libraries tailored to the contents of a specific image.
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You would use the Extensible SDK if you want a toolchain experience
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supplemented with the powerful set of <filename>devtool</filename>
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commands tailored for the Yocto Project environment.
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</para>
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<para>
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The installed extensible SDK consists of several files and
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directories.
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Basically, it contains an SDK environment setup script, some
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configuration files, an internal build system, and the
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<filename>devtool</filename> functionality.
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</para>
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</section>
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<section id='sdk-setting-up-to-use-the-extensible-sdk'>
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<title>Setting Up to Use the Extensible SDK</title>
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<para>
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The first thing you need to do is install the SDK on your host
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development machine by running the <filename>*.sh</filename>
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installation script.
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</para>
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<para>
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You can download a tarball installer, which includes the
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pre-built toolchain, the <filename>runqemu</filename>
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script, the internal build system, <filename>devtool</filename>,
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and support files from the appropriate directory under
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<ulink url='&YOCTO_TOOLCHAIN_DL_URL;'></ulink>.
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Toolchains are available for 32-bit and 64-bit x86 development
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systems from the <filename>i686</filename> and
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<filename>x86_64</filename> directories, respectively.
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The toolchains the Yocto Project provides are based off the
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<filename>core-image-sato</filename> image and contain
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libraries appropriate for developing against that image.
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Each type of development system supports five or more target
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architectures.
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</para>
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<para>
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The names of the tarball installer scripts are such that a
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string representing the host system appears first in the
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filename and then is immediately followed by a string
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representing the target architecture.
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An extensible SDK has the string "-ext" as part of the name.
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<literallayout class='monospaced'>
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poky-glibc-<replaceable>host_system</replaceable>-<replaceable>image_type</replaceable>-<replaceable>arch</replaceable>-toolchain-ext-<replaceable>release_version</replaceable>.sh
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Where:
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<replaceable>host_system</replaceable> is a string representing your development system:
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i686 or x86_64.
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<replaceable>image_type</replaceable> is the image for which the SDK was built.
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<replaceable>arch</replaceable> is a string representing the tuned target architecture:
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i586, x86_64, powerpc, mips, armv7a or armv5te
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<replaceable>release_version</replaceable> is a string representing the release number of the
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Yocto Project:
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&DISTRO;, &DISTRO;+snapshot
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</literallayout>
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For example, the following SDK installer is for a 64-bit
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development host system and a i586-tuned target architecture
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based off the SDK for <filename>core-image-sato</filename> and
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using the current &DISTRO; snapshot:
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<literallayout class='monospaced'>
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poky-glibc-x86_64-core-image-sato-i586-toolchain-ext-&DISTRO;.sh
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</literallayout>
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<note>
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As an alternative to downloading an SDK, you can build the
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SDK installer.
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For information on building the installer, see the
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"<link linkend='sdk-building-an-sdk-installer'>Building an SDK Installer</link>"
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section.
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Another helpful resource for building an installer is the
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<ulink url='https://wiki.yoctoproject.org/wiki/TipsAndTricks/RunningEclipseAgainstBuiltImage'>Cookbook guide to Making an Eclipse Debug Capable Image</ulink>
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wiki page.
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This wiki page focuses on development when using the Eclipse
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IDE.
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</note>
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</para>
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<para>
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The SDK and toolchains are self-contained and by default are
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installed into the <filename>poky_sdk</filename> folder in your
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home directory.
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You can choose to install the extensible SDK in any location when
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you run the installer.
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However, the location you choose needs to be writable for whichever
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users need to use the SDK, since files will need to be written
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under that directory during the normal course of operation.
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</para>
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<para>
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The following command shows how to run the installer given a
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toolchain tarball for a 64-bit x86 development host system and
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a 64-bit x86 target architecture.
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The example assumes the SDK installer is located in
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<filename>~/Downloads/</filename>.
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<note>
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If you do not have write permissions for the directory
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into which you are installing the SDK, the installer
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notifies you and exits.
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Be sure you have write permissions in the directory and
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run the installer again.
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</note>
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<literallayout class='monospaced'>
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$ ./poky-glibc-x86_64-core-image-minimal-core2-64-toolchain-ext-&DISTRO;.sh
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Poky (Yocto Project Reference Distro) Extensible SDK installer version &DISTRO;
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===================================================================================
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Enter target directory for SDK (default: ~/poky_sdk):
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You are about to install the SDK to "/home/scottrif/poky_sdk". Proceed[Y/n]? Y
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Extracting SDK......................................................................done
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Setting it up...
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Extracting buildtools...
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Preparing build system...
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done
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SDK has been successfully set up and is ready to be used.
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Each time you wish to use the SDK in a new shell session, you need to source the environment setup script e.g.
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$ . /home/scottrif/poky_sdk/environment-setup-core2-64-poky-linux
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</literallayout>
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</para>
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</section>
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<section id='sdk-running-the-extensible-sdk-environment-setup-script'>
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<title>Running the Extensible SDK Environment Setup Script</title>
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<para>
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Once you have the SDK installed, you must run the SDK environment
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setup script before you can actually use it.
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This setup script resides in the directory you chose when you
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installed the SDK, which is either the default
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<filename>poky_sdk</filename> directory or the directory you
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chose during installation.
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</para>
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<para>
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Before running the script, be sure it is the one that matches the
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architecture for which you are developing.
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Environment setup scripts begin with the string
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"<filename>environment-setup</filename>" and include as part of
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their name the tuned target architecture.
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As an example, the following commands set the working directory
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to where the SDK was installed and then source the environment
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setup script.
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In this example, the setup script is for an IA-based
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target machine using i586 tuning:
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<literallayout class='monospaced'>
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$ cd /home/scottrif/poky_sdk
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$ source environment-setup-core2-64-poky-linux
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SDK environment now set up; additionally you may now run devtool to perform development tasks.
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Run devtool --help for further details.
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</literallayout>
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When you run the setup script, many environment variables are
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defined:
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<literallayout class='monospaced'>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-SDKTARGETSYSROOT'><filename>SDKTARGETSYSROOT</filename></ulink> - The path to the sysroot used for cross-compilation
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<ulink url='&YOCTO_DOCS_REF_URL;#var-PKG_CONFIG_PATH'><filename>PKG_CONFIG_PATH</filename></ulink> - The path to the target pkg-config files
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CONFIG_SITE'><filename>CONFIG_SITE</filename></ulink> - A GNU autoconf site file preconfigured for the target
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CC'><filename>CC</filename></ulink> - The minimal command and arguments to run the C compiler
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CXX'><filename>CXX</filename></ulink> - The minimal command and arguments to run the C++ compiler
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CPP'><filename>CPP</filename></ulink> - The minimal command and arguments to run the C preprocessor
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<ulink url='&YOCTO_DOCS_REF_URL;#var-AS'><filename>AS</filename></ulink> - The minimal command and arguments to run the assembler
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<ulink url='&YOCTO_DOCS_REF_URL;#var-LD'><filename>LD</filename></ulink> - The minimal command and arguments to run the linker
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<ulink url='&YOCTO_DOCS_REF_URL;#var-GDB'><filename>GDB</filename></ulink> - The minimal command and arguments to run the GNU Debugger
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<ulink url='&YOCTO_DOCS_REF_URL;#var-STRIP'><filename>STRIP</filename></ulink> - The minimal command and arguments to run 'strip', which strips symbols
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<ulink url='&YOCTO_DOCS_REF_URL;#var-RANLIB'><filename>RANLIB</filename></ulink> - The minimal command and arguments to run 'ranlib'
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<ulink url='&YOCTO_DOCS_REF_URL;#var-OBJCOPY'><filename>OBJCOPY</filename></ulink> - The minimal command and arguments to run 'objcopy'
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<ulink url='&YOCTO_DOCS_REF_URL;#var-OBJDUMP'><filename>OBJDUMP</filename></ulink> - The minimal command and arguments to run 'objdump'
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<ulink url='&YOCTO_DOCS_REF_URL;#var-AR'><filename>AR</filename></ulink> - The minimal command and arguments to run 'ar'
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<ulink url='&YOCTO_DOCS_REF_URL;#var-NM'><filename>NM</filename></ulink> - The minimal command and arguments to run 'nm'
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<ulink url='&YOCTO_DOCS_REF_URL;#var-TARGET_PREFIX'><filename>TARGET_PREFIX</filename></ulink> - The toolchain binary prefix for the target tools
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CROSS_COMPILE'><filename>CROSS_COMPILE</filename></ulink> - The toolchain binary prefix for the target tools
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CONFIGURE_FLAGS'><filename>CONFIGURE_FLAGS</filename></ulink> - The minimal arguments for GNU configure
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CFLAGS'><filename>CFLAGS</filename></ulink> - Suggested C flags
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CXXFLAGS'><filename>CXXFLAGS</filename></ulink> - Suggested C++ flags
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<ulink url='&YOCTO_DOCS_REF_URL;#var-LDFLAGS'><filename>LDFLAGS</filename></ulink> - Suggested linker flags when you use CC to link
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<ulink url='&YOCTO_DOCS_REF_URL;#var-CPPFLAGS'><filename>CPPFLAGS</filename></ulink> - Suggested preprocessor flags
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</literallayout>
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</para>
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</section>
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<section id='using-devtool-in-your-sdk-workflow'>
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<title>Using <filename>devtool</filename> in Your SDK Workflow</title>
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<para>
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The cornerstone of the extensible SDK is a command-line tool
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called <filename>devtool</filename>.
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This tool provides a number of features that help
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you build, test and package software within the extensible SDK, and
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optionally integrate it into an image built by the OpenEmbedded
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build system.
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</para>
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<para>
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The <filename>devtool</filename> command line is organized
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similarly to
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<ulink url='&YOCTO_DOCS_DEV_URL;#git'>Git</ulink> in that it has a
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number of sub-commands for each function.
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You can run <filename>devtool --help</filename> to see all the
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commands.
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</para>
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<para>
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Three <filename>devtool</filename> subcommands that provide
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entry-points into development are:
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<itemizedlist>
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<listitem><para>
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<emphasis><filename>devtool add</filename></emphasis>:
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Assists in adding new software to be built.
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</para></listitem>
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<listitem><para>
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<emphasis><filename>devtool modify</filename></emphasis>:
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Sets up an environment to enable you to modify the source of
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an existing component.
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</para></listitem>
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<listitem><para>
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<emphasis><filename>devtool upgrade</filename></emphasis>:
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Updates an existing recipe so that you can build it for
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an updated set of source files.
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</para></listitem>
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</itemizedlist>
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As with the OpenEmbedded build system, "recipes" represent software
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packages within <filename>devtool</filename>.
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When you use <filename>devtool add</filename>, a recipe is
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automatically created.
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When you use <filename>devtool modify</filename>, the specified
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existing recipe is used in order to determine where to get the source
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code and how to patch it.
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In both cases, an environment is set up so that when you build the
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recipe a source tree that is under your control is used in order to
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allow you to make changes to the source as desired.
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By default, both new recipes and the source go into a "workspace"
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directory under the SDK.
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</para>
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<para>
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The remainder of this section presents the
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<filename>devtool add</filename>,
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<filename>devtool modify</filename>, and
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<filename>devtool upgrade</filename> workflows.
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</para>
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<section id='sdk-use-devtool-to-add-an-application'>
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<title>Use <filename>devtool add</filename> to Add an Application</title>
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<para>
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The <filename>devtool add</filename> command generates
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a new recipe based on existing source code.
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This command takes advantage of the
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<ulink url='&YOCTO_DOCS_DEV_URL;#devtool-the-workspace-layer-structure'>workspace</ulink>
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layer that many <filename>devtool</filename> commands
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use.
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The command is flexible enough to allow you to extract source
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code into both the workspace or a separate local Git repository
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and to use existing code that does not need to be extracted.
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</para>
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<para>
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Depending on your particular scenario, the arguments and options
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you use with <filename>devtool add</filename> form different
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combinations.
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The following diagram shows common development flows
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you would use with the <filename>devtool add</filename>
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command:
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</para>
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<para>
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<imagedata fileref="figures/sdk-devtool-add-flow.png" align="center" />
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</para>
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<para>
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<orderedlist>
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<listitem><para><emphasis>Generating the New Recipe</emphasis>:
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The top part of the flow shows three scenarios by which
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you could use <filename>devtool add</filename> to
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generate a recipe based on existing source code.</para>
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<para>In a shared development environment, it is
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typical where other developers are responsible for
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various areas of source code.
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As a developer, you are probably interested in using
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that source code as part of your development using
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the Yocto Project.
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All you need is access to the code, a recipe, and a
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controlled area in which to do your work.</para>
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<para>Within the diagram, three possible scenarios
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feed into the <filename>devtool add</filename> workflow:
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<itemizedlist>
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<listitem><para><emphasis>Left</emphasis>:
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The left scenario represents a common situation
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where the source code does not exist locally
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and needs to be extracted.
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In this situation, you just let it get
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extracted to the default workspace - you do not
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want it in some specific location outside of the
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workspace.
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Thus, everything you need will be located in the
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workspace:
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<literallayout class='monospaced'>
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$ devtool add <replaceable>recipe fetchuri</replaceable>
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</literallayout>
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With this command, <filename>devtool</filename>
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creates a recipe and an append file in the
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workspace as well as extracts the upstream
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source files into a local Git repository also
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within the <filename>sources</filename> folder.
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</para></listitem>
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<listitem><para><emphasis>Middle</emphasis>:
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The middle scenario also represents a situation where
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the source code does not exist locally.
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In this case, the code is again upstream
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and needs to be extracted to some
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local area - this time outside of the default
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workspace.
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If required, <filename>devtool</filename>
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always creates
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a Git repository locally during the extraction.
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Furthermore, the first positional argument
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<replaceable>srctree</replaceable> in this case
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identifies where the
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<filename>devtool add</filename> command
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will locate the extracted code outside of the
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workspace:
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<literallayout class='monospaced'>
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$ devtool add <replaceable>recipe srctree fetchuri</replaceable>
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</literallayout>
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In summary, the source code is pulled from
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<replaceable>fetchuri</replaceable> and extracted
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into the location defined by
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<replaceable>srctree</replaceable> as a local
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Git repository.</para>
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<para>Within workspace, <filename>devtool</filename>
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creates both the recipe and an append file
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for the recipe.
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</para></listitem>
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<listitem><para><emphasis>Right</emphasis>:
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The right scenario represents a situation
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where the source tree (srctree) has been
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previously prepared outside of the
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<filename>devtool</filename> workspace.
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</para>
|
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<para>The following command names the recipe
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and identifies where the existing source tree
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is located:
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<literallayout class='monospaced'>
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$ devtool add <replaceable>recipe srctree</replaceable>
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</literallayout>
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The command examines the source code and creates
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a recipe for it placing the recipe into the
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workspace.</para>
|
|
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<para>Because the extracted source code already exists,
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<filename>devtool</filename> does not try to
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relocate it into the workspace - just the new
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the recipe is placed in the workspace.</para>
|
|
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<para>Aside from a recipe folder, the command
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also creates an append folder and places an initial
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<filename>*.bbappend</filename> within.
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</para></listitem>
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</itemizedlist>
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</para></listitem>
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<listitem><para><emphasis>Edit the Recipe</emphasis>:
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At this point, you can use <filename>devtool edit-recipe</filename>
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to open up the editor as defined by the
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<filename>$EDITOR</filename> environment variable
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and modify the file:
|
|
<literallayout class='monospaced'>
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$ devtool edit-recipe <replaceable>recipe</replaceable>
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</literallayout>
|
|
From within the editor, you can make modifications to the
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recipe that take affect when you build it later.
|
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</para></listitem>
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<listitem><para><emphasis>Build the Recipe or Rebuild the Image</emphasis>:
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At this point in the flow, the next step you
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take depends on what you are going to do with
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the new code.</para>
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<para>If you need to take the build output and eventually
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move it to the target hardware, you would use
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<filename>devtool build</filename>:
|
|
<literallayout class='monospaced'>
|
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$ devtool build <replaceable>recipe</replaceable>
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|
</literallayout></para>
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|
<para>On the other hand, if you want an image to
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contain the recipe's packages for immediate deployment
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onto a device (e.g. for testing purposes), you can use
|
|
the <filename>devtool build-image</filename> command:
|
|
<literallayout class='monospaced'>
|
|
$ devtool build-image <replaceable>image</replaceable>
|
|
</literallayout>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Deploy the Build Output</emphasis>:
|
|
When you use the <filename>devtool build</filename>
|
|
command to build out your recipe, you probably want to
|
|
see if the resulting build output works as expected on target
|
|
hardware.
|
|
<note>
|
|
This step assumes you have a previously built
|
|
image that is already either running in QEMU or
|
|
running on actual hardware.
|
|
Also, it is assumed that for deployment of the image
|
|
to the target, SSH is installed in the image and if
|
|
the image is running on real hardware that you have
|
|
network access to and from your development machine.
|
|
</note>
|
|
You can deploy your build output to that target hardware by
|
|
using the <filename>devtool deploy-target</filename> command:
|
|
<literallayout class='monospaced'>
|
|
$ devtool deploy-target <replaceable>recipe target</replaceable>
|
|
</literallayout>
|
|
The <replaceable>target</replaceable> is a live target machine
|
|
running as an SSH server.</para>
|
|
|
|
<para>You can, of course, also deploy the image you build
|
|
using the <filename>devtool build-image</filename> command
|
|
to actual hardware.
|
|
However, <filename>devtool</filename> does not provide a
|
|
specific command that allows you to do this.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
<emphasis>Finish Your Work With the Recipe</emphasis>:
|
|
The <filename>devtool finish</filename> command creates
|
|
any patches corresponding to commits in the local
|
|
Git repository, moves the new recipe to a more permanent
|
|
layer, and then resets the recipe so that the recipe is
|
|
built normally rather than from the workspace.
|
|
<literallayout class='monospaced'>
|
|
$ devtool finish <replaceable>recipe layer</replaceable>
|
|
</literallayout>
|
|
<note>
|
|
Any changes you want to turn into patches must be
|
|
committed to the Git repository in the source tree.
|
|
</note></para>
|
|
|
|
<para>As mentioned, the <filename>devtool finish</filename>
|
|
command moves the final recipe to its permanent layer.
|
|
</para>
|
|
|
|
<para>As a final process of the
|
|
<filename>devtool finish</filename> command, the state
|
|
of the standard layers and the upstream source is
|
|
restored so that you can build the recipe from those
|
|
areas rather than the workspace.
|
|
<note>
|
|
You can use the <filename>devtool reset</filename>
|
|
command to put things back should you decide you
|
|
do not want to proceed with your work.
|
|
If you do use this command, realize that the source
|
|
tree is preserved.
|
|
</note>
|
|
</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-devtool-use-devtool-modify-to-modify-the-source-of-an-existing-component'>
|
|
<title>Use <filename>devtool modify</filename> to Modify the Source of an Existing Component</title>
|
|
|
|
<para>
|
|
The <filename>devtool modify</filename> command prepares the
|
|
way to work on existing code that already has a recipe in
|
|
place.
|
|
The command is flexible enough to allow you to extract code,
|
|
specify the existing recipe, and keep track of and gather any
|
|
patch files from other developers that are
|
|
associated with the code.
|
|
</para>
|
|
|
|
<para>
|
|
Depending on your particular scenario, the arguments and options
|
|
you use with <filename>devtool modify</filename> form different
|
|
combinations.
|
|
The following diagram shows common development flows
|
|
you would use with the <filename>devtool modify</filename>
|
|
command:
|
|
</para>
|
|
|
|
<para>
|
|
<imagedata fileref="figures/sdk-devtool-modify-flow.png" align="center" />
|
|
</para>
|
|
|
|
<para>
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Preparing to Modify the Code</emphasis>:
|
|
The top part of the flow shows three scenarios by which
|
|
you could use <filename>devtool modify</filename> to
|
|
prepare to work on source files.
|
|
Each scenario assumes the following:
|
|
<itemizedlist>
|
|
<listitem><para>The recipe exists in some layer external
|
|
to the <filename>devtool</filename> workspace.
|
|
</para></listitem>
|
|
<listitem><para>The source files exist upstream in an
|
|
un-extracted state or locally in a previously
|
|
extracted state.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
The typical situation is where another developer has
|
|
created some layer for use with the Yocto Project and
|
|
their recipe already resides in that layer.
|
|
Furthermore, their source code is readily available
|
|
either upstream or locally.
|
|
<itemizedlist>
|
|
<listitem><para><emphasis>Left</emphasis>:
|
|
The left scenario represents a common situation
|
|
where the source code does not exist locally
|
|
and needs to be extracted.
|
|
In this situation, the source is extracted
|
|
into the default workspace location.
|
|
The recipe, in this scenario, is in its own
|
|
layer outside the workspace
|
|
(i.e.
|
|
<filename>meta-</filename><replaceable>layername</replaceable>).
|
|
</para>
|
|
|
|
<para>The following command identifies the recipe
|
|
and by default extracts the source files:
|
|
<literallayout class='monospaced'>
|
|
$ devtool modify <replaceable>recipe</replaceable>
|
|
</literallayout>
|
|
Once <filename>devtool</filename>locates the recipe,
|
|
it uses the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
variable to locate the source code and
|
|
any local patch files from other developers are
|
|
located.
|
|
<note>
|
|
You cannot provide an URL for
|
|
<replaceable>srctree</replaceable> when using the
|
|
<filename>devtool modify</filename> command.
|
|
</note>
|
|
With this scenario, however, since no
|
|
<replaceable>srctree</replaceable> argument exists, the
|
|
<filename>devtool modify</filename> command by default
|
|
extracts the source files to a Git structure.
|
|
Furthermore, the location for the extracted source is the
|
|
default area within the workspace.
|
|
The result is that the command sets up both the source
|
|
code and an append file within the workspace with the
|
|
recipe remaining in its original location.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Middle</emphasis>:
|
|
The middle scenario represents a situation where
|
|
the source code also does not exist locally.
|
|
In this case, the code is again upstream
|
|
and needs to be extracted to some
|
|
local area as a Git repository.
|
|
The recipe, in this scenario, is again in its own
|
|
layer outside the workspace.</para>
|
|
|
|
<para>The following command tells
|
|
<filename>devtool</filename> what recipe with
|
|
which to work and, in this case, identifies a local
|
|
area for the extracted source files that is outside
|
|
of the default workspace:
|
|
<literallayout class='monospaced'>
|
|
$ devtool modify <replaceable>recipe srctree</replaceable>
|
|
</literallayout>
|
|
As with all extractions, the command uses
|
|
the recipe's <filename>SRC_URI</filename> to locate the
|
|
source files.
|
|
Once the files are located, the command by default
|
|
extracts them.
|
|
Providing the <replaceable>srctree</replaceable>
|
|
argument instructs <filename>devtool</filename> where
|
|
place the extracted source.</para>
|
|
|
|
<para>Within workspace, <filename>devtool</filename>
|
|
creates an append file for the recipe.
|
|
The recipe remains in its original location but
|
|
the source files are extracted to the location you
|
|
provided with <replaceable>srctree</replaceable>.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Right</emphasis>:
|
|
The right scenario represents a situation
|
|
where the source tree
|
|
(<replaceable>srctree</replaceable>) exists as a
|
|
previously extracted Git structure outside of
|
|
the <filename>devtool</filename> workspace.
|
|
In this example, the recipe also exists
|
|
elsewhere in its own layer.
|
|
</para>
|
|
|
|
<para>The following command tells
|
|
<filename>devtool</filename> the recipe
|
|
with which to work, uses the "-n" option to indicate
|
|
source does not need to be extracted, and uses
|
|
<replaceable>srctree</replaceable> to point to the
|
|
previously extracted source files:
|
|
<literallayout class='monospaced'>
|
|
$ devtool modify -n <replaceable>recipe srctree</replaceable>
|
|
</literallayout>
|
|
</para>
|
|
|
|
<para>Once the command finishes, it creates only
|
|
an append file for the recipe in the workspace.
|
|
The recipe and the source code remain in their
|
|
original locations.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Edit the Source</emphasis>:
|
|
Once you have used the <filename>devtool modify</filename>
|
|
command, you are free to make changes to the source
|
|
files.
|
|
You can use any editor you like to make and save
|
|
your source code modifications.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Build the Recipe</emphasis>:
|
|
Once you have updated the source files, you can build
|
|
the recipe.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Deploy the Build Output</emphasis>:
|
|
When you use the <filename>devtool build</filename>
|
|
command to build out your recipe, you probably want to see
|
|
if the resulting build output works as expected on target
|
|
hardware.
|
|
<note>
|
|
This step assumes you have a previously built
|
|
image that is already either running in QEMU or
|
|
running on actual hardware.
|
|
Also, it is assumed that for deployment of the image
|
|
to the target, SSH is installed in the image and if
|
|
the image is running on real hardware that you have
|
|
network access to and from your development machine.
|
|
</note>
|
|
You can deploy your build output to that target hardware by
|
|
using the <filename>devtool deploy-target</filename> command:
|
|
<literallayout class='monospaced'>
|
|
$ devtool deploy-target <replaceable>recipe target</replaceable>
|
|
</literallayout>
|
|
The <replaceable>target</replaceable> is a live target machine
|
|
running as an SSH server.</para>
|
|
|
|
<para>You can, of course, also deploy the image you build
|
|
using the <filename>devtool build-image</filename> command
|
|
to actual hardware.
|
|
However, <filename>devtool</filename> does not provide a
|
|
specific command that allows you to do this.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
<emphasis>Finish Your Work With the Recipe</emphasis>:
|
|
The <filename>devtool finish</filename> command creates
|
|
any patches corresponding to commits in the local
|
|
Git repository, updates the recipe to point to them
|
|
(or creates a <filename>.bbappend</filename> file to do
|
|
so, depending on the specified destination layer), and
|
|
then resets the recipe so that the recipe is built normally
|
|
rather than from the workspace.
|
|
<literallayout class='monospaced'>
|
|
$ devtool finish <replaceable>recipe layer</replaceable>
|
|
</literallayout>
|
|
<note>
|
|
Any changes you want to turn into patches must be
|
|
committed to the Git repository in the source tree.
|
|
</note></para>
|
|
|
|
<para>Because there is no need to move the recipe,
|
|
<filename>devtool finish</filename> either updates the
|
|
original recipe in the original layer or the command
|
|
creates a <filename>.bbappend</filename> in a different
|
|
layer as provided by <replaceable>layer</replaceable>.
|
|
</para>
|
|
|
|
<para>As a final process of the
|
|
<filename>devtool finish</filename> command, the state
|
|
of the standard layers and the upstream source is
|
|
restored so that you can build the recipe from those
|
|
areas rather than the workspace.
|
|
<note>
|
|
You can use the <filename>devtool reset</filename>
|
|
command to put things back should you decide you
|
|
do not want to proceed with your work.
|
|
If you do use this command, realize that the source
|
|
tree is preserved.
|
|
</note>
|
|
</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-devtool-use-devtool-upgrade-to-create-a-version-of-the-recipe-that-supports-a-newer-version-of-the-software'>
|
|
<title>Use <filename>devtool upgrade</filename> to Create a Version of the Recipe that Supports a Newer Version of the Software</title>
|
|
|
|
<para>
|
|
The <filename>devtool upgrade</filename> command updates
|
|
an existing recipe so that you can build it for an updated
|
|
set of source files.
|
|
The command is flexible enough to allow you to specify
|
|
source code revision and versioning schemes, extract code into
|
|
or out of the <filename>devtool</filename> workspace, and
|
|
work with any source file forms that the fetchers support.
|
|
</para>
|
|
|
|
<para>
|
|
Depending on your particular scenario, the arguments and options
|
|
you use with <filename>devtool upgrade</filename> form different
|
|
combinations.
|
|
The following diagram shows a common development flow
|
|
you would use with the <filename>devtool modify</filename>
|
|
command:
|
|
</para>
|
|
|
|
<para>
|
|
<imagedata fileref="figures/sdk-devtool-upgrade-flow.png" align="center" />
|
|
</para>
|
|
|
|
<para>
|
|
<orderedlist>
|
|
<listitem><para><emphasis>Initiate the Upgrade</emphasis>:
|
|
The top part of the flow shows a typical scenario by which
|
|
you could use <filename>devtool upgrade</filename>.
|
|
The following conditions exist:
|
|
<itemizedlist>
|
|
<listitem><para>The recipe exists in some layer external
|
|
to the <filename>devtool</filename> workspace.
|
|
</para></listitem>
|
|
<listitem><para>The source files for the new release
|
|
exist adjacent to the same location pointed to by
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
in the recipe (e.g. a tarball with the new version
|
|
number in the name, or as a different revision in
|
|
the upstream Git repository).
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
A common situation is where third-party software has
|
|
undergone a revision so that it has been upgraded.
|
|
The recipe you have access to is likely in your own layer.
|
|
Thus, you need to upgrade the recipe to use the
|
|
newer version of the software:
|
|
<literallayout class='monospaced'>
|
|
$ devtool upgrade -V <replaceable>version recipe</replaceable>
|
|
</literallayout>
|
|
By default, the <filename>devtool upgrade</filename> command
|
|
extracts source code into the <filename>sources</filename>
|
|
directory in the workspace.
|
|
If you want the code extracted to any other location, you
|
|
need to provide the <replaceable>srctree</replaceable>
|
|
positional argument with the command as follows:
|
|
<literallayout class='monospaced'>
|
|
$ devtool upgrade -V <replaceable>version recipe srctree</replaceable>
|
|
</literallayout>
|
|
Also, in this example, the "-V" option is used to specify
|
|
the new version.
|
|
If the source files pointed to by the
|
|
<filename>SRC_URI</filename> statement in the recipe are
|
|
in a Git repository, you must provide the "-S" option and
|
|
specify a revision for the software.</para>
|
|
|
|
<para>Once <filename>devtool</filename> locates the recipe,
|
|
it uses the <filename>SRC_URI</filename> variable to locate
|
|
the source code and any local patch files from other
|
|
developers are located.
|
|
The result is that the command sets up the source
|
|
code, the new version of the recipe, and an append file
|
|
all within the workspace.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Resolve any Conflicts created by the Upgrade</emphasis>:
|
|
At this point, there could be some conflicts due to the
|
|
software being upgraded to a new version.
|
|
This would occur if your recipe specifies some patch files in
|
|
<filename>SRC_URI</filename> that conflict with changes
|
|
made in the new version of the software.
|
|
If this is the case, you need to resolve the conflicts
|
|
by editing the source and following the normal
|
|
<filename>git rebase</filename> conflict resolution
|
|
process.</para>
|
|
<para>Before moving onto the next step, be sure to resolve any
|
|
such conflicts created through use of a newer or different
|
|
version of the software.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Build the Recipe</emphasis>:
|
|
Once you have your recipe in order, you can build it.
|
|
You can either use <filename>devtool build</filename> or
|
|
<filename>bitbake</filename>.
|
|
Either method produces build output that is stored
|
|
in
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-TMPDIR'><filename>TMPDIR</filename></ulink>.
|
|
</para></listitem>
|
|
<listitem><para><emphasis>Deploy the Build Output</emphasis>:
|
|
When you use the <filename>devtool build</filename>
|
|
command or <filename>bitbake</filename> to build out your
|
|
recipe, you probably want to see if the resulting build
|
|
output works as expected on target hardware.
|
|
<note>
|
|
This step assumes you have a previously built
|
|
image that is already either running in QEMU or
|
|
running on actual hardware.
|
|
Also, it is assumed that for deployment of the image
|
|
to the target, SSH is installed in the image and if
|
|
the image is running on real hardware that you have
|
|
network access to and from your development machine.
|
|
</note>
|
|
You can deploy your build output to that target hardware by
|
|
using the <filename>devtool deploy-target</filename> command:
|
|
<literallayout class='monospaced'>
|
|
$ devtool deploy-target <replaceable>recipe target</replaceable>
|
|
</literallayout>
|
|
The <replaceable>target</replaceable> is a live target machine
|
|
running as an SSH server.</para>
|
|
<para>You can, of course, also deploy the image you build
|
|
using the <filename>devtool build-image</filename> command
|
|
to actual hardware.
|
|
However, <filename>devtool</filename> does not provide a
|
|
specific command that allows you to do this.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
<emphasis>Finish Your Work With the Recipe</emphasis>:
|
|
The <filename>devtool finish</filename> command creates
|
|
any patches corresponding to commits in the local
|
|
Git repository, moves the new recipe to a more permanent
|
|
layer, and then resets the recipe so that the recipe is
|
|
built normally rather than from the workspace.
|
|
If you specify a destination layer that is the same as
|
|
the original source, then the old version of the
|
|
recipe and associated files will be removed prior to
|
|
adding the new version.
|
|
<literallayout class='monospaced'>
|
|
$ devtool finish <replaceable>recipe layer</replaceable>
|
|
</literallayout>
|
|
<note>
|
|
Any changes you want to turn into patches must be
|
|
committed to the Git repository in the source tree.
|
|
</note></para>
|
|
<para>As a final process of the
|
|
<filename>devtool finish</filename> command, the state
|
|
of the standard layers and the upstream source is
|
|
restored so that you can build the recipe from those
|
|
areas rather than the workspace.
|
|
<note>
|
|
You can use the <filename>devtool reset</filename>
|
|
command to put things back should you decide you
|
|
do not want to proceed with your work.
|
|
If you do use this command, realize that the source
|
|
tree is preserved.
|
|
</note>
|
|
</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='sdk-a-closer-look-at-devtool-add'>
|
|
<title>A Closer Look at <filename>devtool add</filename></title>
|
|
|
|
<para>
|
|
The <filename>devtool add</filename> command automatically creates a
|
|
recipe based on the source tree with which you provide it.
|
|
Currently, the command has support for the following:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
Autotools (<filename>autoconf</filename> and
|
|
<filename>automake</filename>)
|
|
</para></listitem>
|
|
<listitem><para>
|
|
CMake
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Scons
|
|
</para></listitem>
|
|
<listitem><para>
|
|
<filename>qmake</filename>
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Plain <filename>Makefile</filename>
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Out-of-tree kernel module
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Binary package (i.e. "-b" option)
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Node.js module
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Python modules that use <filename>setuptools</filename>
|
|
or <filename>distutils</filename>
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
|
|
<para>
|
|
Apart from binary packages, the determination of how a source tree
|
|
should be treated is automatic based on the files present within
|
|
that source tree.
|
|
For example, if a <filename>CMakeLists.txt</filename> file is found,
|
|
then the source tree is assumed to be using
|
|
CMake and is treated accordingly.
|
|
<note>
|
|
In most cases, you need to edit the automatically generated
|
|
recipe in order to make it build properly.
|
|
Typically, you would go through several edit and build cycles
|
|
until you can build the recipe.
|
|
Once the recipe can be built, you could use possible further
|
|
iterations to test the recipe on the target device.
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
The remainder of this section covers specifics regarding how parts
|
|
of the recipe are generated.
|
|
</para>
|
|
|
|
<section id='sdk-name-and-version'>
|
|
<title>Name and Version</title>
|
|
|
|
<para>
|
|
If you do not specify a name and version on the command
|
|
line, <filename>devtool add</filename> attempts to determine
|
|
the name and version of the software being built from
|
|
various metadata within the source tree.
|
|
Furthermore, the command sets the name of the created recipe
|
|
file accordingly.
|
|
If the name or version cannot be determined, the
|
|
<filename>devtool add</filename> command prints an error and
|
|
you must re-run the command with both the name and version
|
|
or just the name or version specified.
|
|
</para>
|
|
|
|
<para>
|
|
Sometimes the name or version determined from the source tree
|
|
might be incorrect.
|
|
For such a case, you must reset the recipe:
|
|
<literallayout class='monospaced'>
|
|
$ devtool reset -n <replaceable>recipename</replaceable>
|
|
</literallayout>
|
|
After running the <filename>devtool reset</filename> command,
|
|
you need to run <filename>devtool add</filename> again and
|
|
provide the name or the version.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-dependency-detection-and-mapping'>
|
|
<title>Dependency Detection and Mapping</title>
|
|
|
|
<para>
|
|
The <filename>devtool add</filename> command attempts to
|
|
detect build-time dependencies and map them to other recipes
|
|
in the system.
|
|
During this mapping, the command fills in the names of those
|
|
recipes in the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-DEPENDS'><filename>DEPENDS</filename></ulink>
|
|
value within the recipe.
|
|
If a dependency cannot be mapped, then a comment is placed in
|
|
the recipe indicating such.
|
|
The inability to map a dependency might be caused because the
|
|
naming is not recognized or because the dependency simply is
|
|
not available.
|
|
For cases where the dependency is not available, you must use
|
|
the <filename>devtool add</filename> command to add an
|
|
additional recipe to satisfy the dependency and then come
|
|
back to the first recipe and add its name to
|
|
<filename>DEPENDS</filename>.
|
|
</para>
|
|
|
|
<para>
|
|
If you need to add runtime dependencies, you can do so by
|
|
adding the following to your recipe:
|
|
<literallayout class='monospaced'>
|
|
RDEPENDS_${PN} += "dependency1 dependency2 ..."
|
|
</literallayout>
|
|
<note>
|
|
The <filename>devtool add</filename> command often cannot
|
|
distinguish between mandatory and optional dependencies.
|
|
Consequently, some of the detected dependencies might
|
|
in fact be optional.
|
|
When in doubt, consult the documentation or the configure
|
|
script for the software the recipe is building for further
|
|
details.
|
|
In some cases, you might find you can substitute the
|
|
dependency for an option to disable the associated
|
|
functionality passed to the configure script.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-license-detection'>
|
|
<title>License Detection</title>
|
|
|
|
<para>
|
|
The <filename>devtool add</filename> command attempts to
|
|
determine if the software you are adding is able to be
|
|
distributed under a common open-source license and sets the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-LICENSE'><filename>LICENSE</filename></ulink>
|
|
value accordingly.
|
|
You should double-check this value against the documentation
|
|
or source files for the software you are building and update
|
|
that <filename>LICENSE</filename> value if necessary.
|
|
</para>
|
|
|
|
<para>
|
|
The <filename>devtool add</filename> command also sets the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-LIC_FILES_CHKSUM'><filename>LIC_FILES_CHKSUM</filename></ulink>
|
|
value to point to all files that appear to be license-related.
|
|
However, license statements often appear in comments at the top
|
|
of source files or within documentation.
|
|
Consequently, you might need to amend the
|
|
<filename>LIC_FILES_CHKSUM</filename> variable to point to one
|
|
or more of those comments if present.
|
|
Setting <filename>LIC_FILES_CHKSUM</filename> is particularly
|
|
important for third-party software.
|
|
The mechanism attempts to ensure correct licensing should you
|
|
upgrade the recipe to a newer upstream version in future.
|
|
Any change in licensing is detected and you receive an error
|
|
prompting you to check the license text again.
|
|
</para>
|
|
|
|
<para>
|
|
If the <filename>devtool add</filename> command cannot
|
|
determine licensing information, the
|
|
<filename>LICENSE</filename> value is set to "CLOSED" and the
|
|
<filename>LIC_FILES_CHKSUM</filename> value remains unset.
|
|
This behavior allows you to continue with development but is
|
|
unlikely to be correct in all cases.
|
|
Consequently, you should check the documentation or source
|
|
files for the software you are building to determine the actual
|
|
license.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-adding-makefile-only-software'>
|
|
<title>Adding Makefile-Only Software</title>
|
|
|
|
<para>
|
|
The use of <filename>make</filename> by itself is very common
|
|
in both proprietary and open source software.
|
|
Unfortunately, Makefiles are often not written with
|
|
cross-compilation in mind.
|
|
Thus, <filename>devtool add</filename> often cannot do very
|
|
much to ensure that these Makefiles build correctly.
|
|
It is very common, for example, to explicitly call
|
|
<filename>gcc</filename> instead of using the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-CC'><filename>CC</filename></ulink>
|
|
variable.
|
|
Usually, in a cross-compilation environment,
|
|
<filename>gcc</filename> is the compiler for the build host
|
|
and the cross-compiler is named something similar to
|
|
<filename>arm-poky-linux-gnueabi-gcc</filename> and might
|
|
require some arguments (e.g. to point to the associated sysroot
|
|
for the target machine).
|
|
</para>
|
|
|
|
<para>
|
|
When writing a recipe for Makefile-only software, keep the
|
|
following in mind:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
You probably need to patch the Makefile to use
|
|
variables instead of hardcoding tools within the
|
|
toolchain such as <filename>gcc</filename> and
|
|
<filename>g++</filename>.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
The environment in which <filename>make</filename> runs
|
|
is set up with various standard variables for
|
|
compilation (e.g. <filename>CC</filename>,
|
|
<filename>CXX</filename>, and so forth) in a similar
|
|
manner to the environment set up by the SDK's
|
|
environment setup script.
|
|
One easy way to see these variables is to run the
|
|
<filename>devtool build</filename> command on the
|
|
recipe and then look in
|
|
<filename>oe-logs/run.do_compile</filename>.
|
|
Towards the top of this file you will see a list of
|
|
environment variables that are being set.
|
|
You can take advantage of these variables within the
|
|
Makefile.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
If the Makefile sets a default for a variable using "=",
|
|
that default overrides the value set in the environment,
|
|
which is usually not desirable.
|
|
In this situation, you can either patch the Makefile
|
|
so it sets the default using the "?=" operator, or
|
|
you can alternatively force the value on the
|
|
<filename>make</filename> command line.
|
|
To force the value on the command line, add the
|
|
variable setting to
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_OEMAKE'><filename>EXTRA_OEMAKE</filename></ulink>
|
|
or
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGECONFIG_CONFARGS'><filename>PACKAGECONFIG_CONFARGS</filename></ulink>
|
|
within the recipe.
|
|
Here is an example using <filename>EXTRA_OEMAKE</filename>:
|
|
<literallayout class='monospaced'>
|
|
EXTRA_OEMAKE += "'CC=${CC}' 'CXX=${CXX}'"
|
|
</literallayout>
|
|
In the above example, single quotes are used around the
|
|
variable settings as the values are likely to contain
|
|
spaces because required default options are passed to
|
|
the compiler.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Hardcoding paths inside Makefiles is often problematic
|
|
in a cross-compilation environment.
|
|
This is particularly true because those hardcoded paths
|
|
often point to locations on the build host and thus
|
|
will either be read-only or will introduce
|
|
contamination into the cross-compilation by virtue of
|
|
being specific to the build host rather than the target.
|
|
Patching the Makefile to use prefix variables or other
|
|
path variables is usually the way to handle this.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Sometimes a Makefile runs target-specific commands such
|
|
as <filename>ldconfig</filename>.
|
|
For such cases, you might be able to simply apply
|
|
patches that remove these commands from the Makefile.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-adding-native-tools'>
|
|
<title>Adding Native Tools</title>
|
|
|
|
<para>
|
|
Often, you need to build additional tools that run on the
|
|
build host system as opposed to the target.
|
|
You should indicate this using one of the following methods
|
|
when you run <filename>devtool add</filename>:
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
Specify the name of the recipe such that it ends
|
|
with "-native".
|
|
Specifying the name like this produces a recipe that
|
|
only builds for the build host.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Specify the "‐‐also-native" option with the
|
|
<filename>devtool add</filename> command.
|
|
Specifying this option creates a recipe file that still
|
|
builds for the target but also creates a variant with
|
|
a "-native" suffix that builds for the build host.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
<note>
|
|
If you need to add a tool that is shipped as part of a
|
|
source tree that builds code for the target, you can
|
|
typically accomplish this by building the native and target
|
|
parts separately rather than within the same compilation
|
|
process.
|
|
Realize though that with the "‐‐also-native" option, you
|
|
can add the tool using just one recipe file.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-adding-node-js-modules'>
|
|
<title>Adding Node.js Modules</title>
|
|
|
|
<para>
|
|
You can use the <filename>devtool add</filename> command two
|
|
different ways to add Node.js modules: 1) Through
|
|
<filename>npm</filename> and, 2) from a repository or local
|
|
source.
|
|
</para>
|
|
|
|
<para>
|
|
Use the following form to add Node.js modules through
|
|
<filename>npm</filename>:
|
|
<literallayout class='monospaced'>
|
|
$ devtool add "npm://registry.npmjs.org;name=forever;version=0.15.1"
|
|
</literallayout>
|
|
The name and version parameters are mandatory.
|
|
Lockdown and shrinkwrap files are generated and pointed to by
|
|
the recipe in order to freeze the version that is fetched for
|
|
the dependencies according to the first time.
|
|
This also saves checksums that are verified on future fetches.
|
|
Together, these behaviors ensure the reproducibility and
|
|
integrity of the build.
|
|
<note><title>Notes</title>
|
|
<itemizedlist>
|
|
<listitem><para>
|
|
You must use quotes around the URL.
|
|
The <filename>devtool add</filename> does not require
|
|
the quotes, but the shell considers ";" as a splitter
|
|
between multiple commands.
|
|
Thus, without the quotes,
|
|
<filename>devtool add</filename> does not receive the
|
|
other parts, which results in several "command not
|
|
found" errors.
|
|
</para></listitem>
|
|
<listitem><para>
|
|
In order to support adding
|
|
Node.js modules, a
|
|
<filename>nodejs</filename> recipe must be part of your
|
|
SDK in order to provide Node.js
|
|
itself.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</note>
|
|
</para>
|
|
|
|
<para>
|
|
As mentioned earlier, you can also add Node.js modules
|
|
directly from a repository or local source tree.
|
|
To add modules this way, use <filename>devtool add</filename> in
|
|
the following form:
|
|
<literallayout class='monospaced'>
|
|
$ devtool add https://github.com/diversario/node-ssdp
|
|
</literallayout>
|
|
In this example, <filename>devtool</filename> fetches the specified
|
|
Git repository, detects that the code is Node.js code, fetches
|
|
dependencies using <filename>npm</filename>, and sets
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
|
|
accordingly.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='sdk-working-with-recipes'>
|
|
<title>Working With Recipes</title>
|
|
|
|
<para>
|
|
When building a recipe with <filename>devtool build</filename> the
|
|
typical build progression is as follows:
|
|
<orderedlist>
|
|
<listitem><para>
|
|
Fetch the source
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Unpack the source
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Configure the source
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Compiling the source
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Install the build output
|
|
</para></listitem>
|
|
<listitem><para>
|
|
Package the installed output
|
|
</para></listitem>
|
|
</orderedlist>
|
|
For recipes in the workspace, fetching and unpacking is disabled
|
|
as the source tree has already been prepared and is persistent.
|
|
Each of these build steps is defined as a function, usually with a
|
|
"do_" prefix.
|
|
These functions are typically shell scripts but can instead be written
|
|
in Python.
|
|
</para>
|
|
|
|
<para>
|
|
If you look at the contents of a recipe, you will see that the
|
|
recipe does not include complete instructions for building the
|
|
software.
|
|
Instead, common functionality is encapsulated in classes inherited
|
|
with the <filename>inherit</filename> directive, leaving the recipe
|
|
to describe just the things that are specific to the software to be
|
|
built.
|
|
A <ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-base'><filename>base</filename></ulink>
|
|
class exists that is implicitly inherited by all recipes and provides
|
|
the functionality that most typical recipes need.
|
|
</para>
|
|
|
|
<para>
|
|
The remainder of this section presents information useful when
|
|
working with recipes.
|
|
</para>
|
|
|
|
<section id='sdk-finding-logs-and-work-files'>
|
|
<title>Finding Logs and Work Files</title>
|
|
|
|
<para>
|
|
When you are debugging a recipe that you previously created using
|
|
<filename>devtool add</filename> or whose source you are modifying
|
|
by using the <filename>devtool modify</filename> command, after
|
|
the first run of <filename>devtool build</filename>, you will
|
|
find some symbolic links created within the source tree:
|
|
<filename>oe-logs</filename>, which points to the directory in
|
|
which log files and run scripts for each build step are created
|
|
and <filename>oe-workdir</filename>, which points to the temporary
|
|
work area for the recipe.
|
|
You can use these links to get more information on what is
|
|
happening at each build step.
|
|
</para>
|
|
|
|
<para>
|
|
These locations under <filename>oe-workdir</filename> are
|
|
particularly useful:
|
|
<itemizedlist>
|
|
<listitem><para><filename>image/</filename>:
|
|
Contains all of the files installed at the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-install'><filename>do_install</filename></ulink>
|
|
stage.
|
|
Within a recipe, this directory is referred to by the
|
|
expression
|
|
<filename>${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-D'><filename>D</filename></ulink><filename>}</filename>.
|
|
</para></listitem>
|
|
<listitem><para><filename>sysroot-destdir/</filename>:
|
|
Contains a subset of files installed within
|
|
<filename>do_install</filename> that have been put into the
|
|
shared sysroot.
|
|
For more information, see the
|
|
"<link linkend='sdk-sharing-files-between-recipes'>Sharing Files Between Recipes</link>"
|
|
section.
|
|
</para></listitem>
|
|
<listitem><para><filename>packages-split/</filename>:
|
|
Contains subdirectories for each package produced by the
|
|
recipe.
|
|
For more information, see the
|
|
"<link linkend='sdk-packaging'>Packaging</link>" section.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-setting-configure-arguments'>
|
|
<title>Setting Configure Arguments</title>
|
|
|
|
<para>
|
|
If the software your recipe is building uses GNU autoconf,
|
|
then a fixed set of arguments is passed to it to enable
|
|
cross-compilation plus any extras specified by
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_OECONF'><filename>EXTRA_OECONF</filename></ulink>
|
|
or
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGECONFIG_CONFARGS'><filename>PACKAGECONFIG_CONFARGS</filename></ulink>
|
|
set within the recipe.
|
|
If you wish to pass additional options, add them to
|
|
<filename>EXTRA_OECONF</filename> or
|
|
<filename>PACKAGECONFIG_CONFARGS</filename>.
|
|
Other supported build tools have similar variables
|
|
(e.g.
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_OECMAKE'><filename>EXTRA_OECMAKE</filename></ulink>
|
|
for CMake,
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_OESCONS'><filename>EXTRA_OESCONS</filename></ulink>
|
|
for Scons, and so forth).
|
|
If you need to pass anything on the <filename>make</filename>
|
|
command line, you can use <filename>EXTRA_OEMAKE</filename> or the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-PACKAGECONFIG_CONFARGS'><filename>PACKAGECONFIG_CONFARGS</filename></ulink>
|
|
variables to do so.
|
|
</para>
|
|
|
|
<para>
|
|
You can use the <filename>devtool configure-help</filename> command
|
|
to help you set the arguments listed in the previous paragraph.
|
|
The command determines the exact options being passed, and shows
|
|
them to you along with any custom arguments specified through
|
|
<filename>EXTRA_OECONF</filename> or
|
|
<filename>PACKAGECONFIG_CONFARGS</filename>.
|
|
If applicable, the command also shows you the output of the
|
|
configure script's "‐‐help" option as a reference.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-sharing-files-between-recipes'>
|
|
<title>Sharing Files Between Recipes</title>
|
|
|
|
<para>
|
|
Recipes often need to use files provided by other recipes on
|
|
the build host.
|
|
For example, an application linking to a common library needs
|
|
access to the library itself and its associated headers.
|
|
The way this access is accomplished within the extensible SDK is
|
|
through the sysroot.
|
|
One sysroot exists per "machine" for which the SDK is being built.
|
|
In practical terms, this means a sysroot exists for the target
|
|
machine, and a sysroot exists for the build host.
|
|
</para>
|
|
|
|
<para>
|
|
Recipes should never write files directly into the sysroot.
|
|
Instead, files should be installed into standard locations
|
|
during the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-install'><filename>do_install</filename></ulink>
|
|
task within the
|
|
<filename>${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-D'><filename>D</filename></ulink><filename>}</filename>
|
|
directory.
|
|
A subset of these files automatically go into the sysroot.
|
|
The reason for this limitation is that almost all files that go
|
|
into the sysroot are cataloged in manifests in order to ensure
|
|
they can be removed later when a recipe is modified or removed.
|
|
Thus, the sysroot is able to remain free from stale files.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-packaging'>
|
|
<title>Packaging</title>
|
|
|
|
<para>
|
|
Packaging is not always particularly relevant within the
|
|
extensible SDK.
|
|
However, if you examine how build output gets into the final image
|
|
on the target device, it is important to understand packaging
|
|
because the contents of the image are expressed in terms of
|
|
packages and not recipes.
|
|
</para>
|
|
|
|
<para>
|
|
During the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-package'><filename>do_package</filename></ulink>
|
|
task, files installed during the
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-install'><filename>do_install</filename></ulink>
|
|
task are split into one main package, which is almost always named
|
|
the same as the recipe, and several other packages.
|
|
This separation is done because not all of those installed files
|
|
are always useful in every image.
|
|
For example, you probably do not need any of the documentation
|
|
installed in a production image.
|
|
Consequently, for each recipe the documentation files are separated
|
|
into a <filename>-doc</filename> package.
|
|
Recipes that package software that has optional modules or
|
|
plugins might do additional package splitting as well.
|
|
</para>
|
|
|
|
<para>
|
|
After building a recipe you can see where files have gone by
|
|
looking in the <filename>oe-workdir/packages-split</filename>
|
|
directory, which contains a subdirectory for each package.
|
|
Apart from some advanced cases, 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 controls splitting.
|
|
The <filename>PACKAGES</filename> variable lists all of the
|
|
packages to be produced, while the <filename>FILES</filename>
|
|
variable specifies which files to include in each package,
|
|
using an override to specify the package.
|
|
For example, <filename>FILES_${PN}</filename> specifies the files
|
|
to go into the main package (i.e. the main package is named the
|
|
same as the recipe and
|
|
<filename>${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PN'><filename>PN</filename></ulink><filename>}</filename>
|
|
evaluates to the recipe name).
|
|
The order of the <filename>PACKAGES</filename> value is significant.
|
|
For each installed file, the first package whose
|
|
<filename>FILES</filename> value matches the file is the package
|
|
into which the file goes.
|
|
Defaults exist for both the <filename>PACKAGES</filename> and
|
|
<filename>FILES</filename> variables.
|
|
Consequently, you might find you do not even need to set these
|
|
variables in your recipe unless the software the recipe is
|
|
building installs files into non-standard locations.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
|
|
<section id='sdk-restoring-the-target-device-to-its-original-state'>
|
|
<title>Restoring the Target Device to its Original State</title>
|
|
|
|
<para>
|
|
If you use the <filename>devtool deploy-target</filename>
|
|
command to write a recipe's build output to the target, and
|
|
you are working on an existing component of the system, then you
|
|
might find yourself in a situation where you need to restore the
|
|
original files that existed prior to running the
|
|
<filename>devtool deploy-target</filename> command.
|
|
Because the <filename>devtool deploy-target</filename> command
|
|
backs up any files it overwrites, you can use the
|
|
<filename>devtool undeploy-target</filename> to restore those files
|
|
and remove any other files the recipe deployed.
|
|
Consider the following example:
|
|
<literallayout class='monospaced'>
|
|
$ devtool undeploy-target lighttpd root@192.168.7.2
|
|
</literallayout>
|
|
If you have deployed multiple applications, you can remove them
|
|
all at once thus restoring the target device back to its
|
|
original state:
|
|
<literallayout class='monospaced'>
|
|
$ devtool undeploy-target -a root@192.168.7.2
|
|
</literallayout>
|
|
Information about files deployed to the target as well as any
|
|
backed up files are stored on the target itself.
|
|
This storage of course requires some additional space
|
|
on the target machine.
|
|
<note>
|
|
The <filename>devtool deploy-target</filename> and
|
|
<filename>devtool undeploy-target</filename> command do not
|
|
currently interact with any package management system on the
|
|
target device (e.g. RPM or OPKG).
|
|
Consequently, you should not intermingle operations
|
|
<filename>devtool deploy-target</filename> and the package
|
|
manager operations on the target device.
|
|
Doing so could result in a conflicting set of files.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-installing-additional-items-into-the-extensible-sdk'>
|
|
<title>Installing Additional Items Into the Extensible SDK</title>
|
|
|
|
<para>
|
|
The extensible SDK typically only comes with a small number of tools
|
|
and libraries out of the box.
|
|
If you have a minimal SDK, then it starts mostly empty and is
|
|
populated on-demand.
|
|
However, sometimes you will need to explicitly install extra items
|
|
into the SDK.
|
|
If you need these extra items, you can first search for the items
|
|
using the <filename>devtool search</filename> command.
|
|
For example, suppose you need to link to libGL but you are not sure
|
|
which recipe provides it.
|
|
You can use the following command to find out:
|
|
<literallayout class='monospaced'>
|
|
$ devtool search libGL
|
|
mesa A free implementation of the OpenGL API
|
|
</literallayout>
|
|
Once you know the recipe (i.e. <filename>mesa</filename> in this
|
|
example), you can install it:
|
|
<literallayout class='monospaced'>
|
|
$ devtool sdk-install mesa
|
|
</literallayout>
|
|
By default, the <filename>devtool sdk-install</filename> assumes the
|
|
item is available in pre-built form from your SDK provider.
|
|
If the item is not available and it is acceptable to build the item
|
|
from source, you can add the "-s" option as follows:
|
|
<literallayout class='monospaced'>
|
|
$ devtool sdk-install -s mesa
|
|
</literallayout>
|
|
It is important to remember that building the item from source takes
|
|
significantly longer than installing the pre-built artifact.
|
|
Also, if no recipe exists for the item you want to add to the SDK, you
|
|
must instead add it using the <filename>devtool add</filename> command.
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-updating-the-extensible-sdk'>
|
|
<title>Updating the Extensible SDK</title>
|
|
|
|
<para>
|
|
If you are working with an extensible SDK that gets occasionally
|
|
updated (e.g. typically when that SDK has been provided to you by
|
|
another party), then you will need to manually pull down those
|
|
updates to your installed SDK.
|
|
</para>
|
|
|
|
<para>
|
|
To update your installed SDK, run the following:
|
|
<literallayout class='monospaced'>
|
|
$ devtool sdk-update
|
|
</literallayout>
|
|
The previous command assumes your SDK provider has set the default
|
|
update URL for you.
|
|
If that URL has not been set, you need to specify it yourself as
|
|
follows:
|
|
<literallayout class='monospaced'>
|
|
$ devtool sdk-update <replaceable>path_to_update_directory</replaceable>
|
|
</literallayout>
|
|
<note>
|
|
The URL needs to point specifically to a published SDK and not an
|
|
SDK installer that you would download and install.
|
|
</note>
|
|
</para>
|
|
</section>
|
|
|
|
<section id='sdk-creating-a-derivative-sdk-with-additional-components'>
|
|
<title>Creating a Derivative SDK With Additional Components</title>
|
|
|
|
<para>
|
|
You might need to produce an SDK that contains your own custom
|
|
libraries for sending to a third party (e.g., if you are a vendor with
|
|
customers needing to build their own software for the target platform).
|
|
If that is the case, then you can produce a derivative SDK based on
|
|
the currently installed SDK fairly easily.
|
|
Use these steps:
|
|
<orderedlist>
|
|
<listitem><para>If necessary, install an extensible SDK that
|
|
you want to use as a base for your derivative SDK.
|
|
</para></listitem>
|
|
<listitem><para>Source the environment script for the SDK.
|
|
</para></listitem>
|
|
<listitem><para>Add the extra libraries or other components
|
|
you want by using the <filename>devtool add</filename>
|
|
command.
|
|
</para></listitem>
|
|
<listitem><para>Run the <filename>devtool build-sdk</filename>
|
|
command.
|
|
</para></listitem>
|
|
</orderedlist>
|
|
The above procedure takes the recipes added to the workspace and
|
|
constructs a new SDK installer containing those recipes and the
|
|
resulting binary artifacts.
|
|
The recipes go into their own separate layer in the constructed
|
|
derivative SDK, leaving the workspace clean and ready for users
|
|
to add their own recipes.
|
|
</para>
|
|
</section>
|
|
</chapter>
|
|
<!--
|
|
vim: expandtab tw=80 ts=4
|
|
-->
|