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diff --git a/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml b/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml new file mode 100644 index 000000000..e51ceb1bf --- /dev/null +++ b/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml @@ -0,0 +1,1142 @@ +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" +"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" +[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > + +<chapter id='ref-structure'> + +<title>Source Directory Structure</title> + +<para> + The <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink> consists of several components. + Understanding them and knowing where they are located is key to using the Yocto Project well. + This chapter describes the Source Directory and gives information about the various + files and directories. +</para> + +<para> + For information on how to establish a local Source Directory on your development system, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#getting-setup'>Getting Set Up</ulink>" + section in the Yocto Project Development Manual. +</para> + +<note> + The OpenEmbedded build system does not support file or directory names that + contain spaces. + Be sure that the Source Directory you use does not contain these types + of names. +</note> + +<section id='structure-core'> + <title>Top-Level Core Components</title> + + <para> + This section describes the top-level components of the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + </para> + + <section id='structure-core-bitbake'> + <title><filename>bitbake/</filename></title> + + <para> + This directory includes a copy of BitBake for ease of use. + The copy usually matches the current stable BitBake release from + the BitBake project. + BitBake, a + <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink> + interpreter, reads the Yocto Project Metadata and runs the tasks + defined by that data. + Failures are usually from the Metadata and not from BitBake itself. + Consequently, most users do not need to worry about BitBake. + </para> + + <para> + When you run the <filename>bitbake</filename> command, the + main BitBake executable, which resides in the + <filename>bitbake/bin/</filename> directory, starts. + Sourcing an environment setup script (e.g. + <link linkend="structure-core-script"><filename>&OE_INIT_FILE;</filename></link> + or + <link linkend="structure-memres-core-script"><filename>oe-init-build-env-memres</filename></link>) + places the <filename>scripts</filename> and + <filename>bitbake/bin</filename> directories (in that order) into + the shell's <filename>PATH</filename> environment variable. + </para> + + <para> + For more information on BitBake, see the + <ulink url='&YOCTO_DOCS_BB_URL;'>BitBake User Manual</ulink>. + </para> + </section> + + <section id='structure-core-build'> + <title><filename>build/</filename></title> + + <para> + This directory contains user configuration files and the output + generated by the OpenEmbedded build system in its standard configuration where + the source tree is combined with the output. + The <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + is created initially when you <filename>source</filename> + the OpenEmbedded build environment setup script + (i.e. + <link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link> + or + <link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>). + </para> + + <para> + It is also possible to place output and configuration + files in a directory separate from the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink> + by providing a directory name when you <filename>source</filename> + the setup script. + For information on separating output from your local + Source Directory files, see the + "<link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link> + and + "<link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>" + sections. + </para> + </section> + + <section id='handbook'> + <title><filename>documentation/</filename></title> + + <para> + This directory holds the source for the Yocto Project documentation + as well as templates and tools that allow you to generate PDF and HTML + versions of the manuals. + Each manual is contained in a sub-folder. + For example, the files for this manual reside in + the <filename>ref-manual/</filename> directory. + </para> + </section> + + <section id='structure-core-meta'> + <title><filename>meta/</filename></title> + + <para> + This directory contains the OpenEmbedded Core metadata. + The directory holds recipes, common classes, and machine + configuration for emulated targets (<filename>qemux86</filename>, + <filename>qemuarm</filename>, and so forth.) + </para> + </section> + + <section id='structure-core-meta-poky'> + <title><filename>meta-poky/</filename></title> + + <para> + This directory contains the configuration for the Poky + reference distribution. + </para> + </section> + + <section id='structure-core-meta-yocto-bsp'> + <title><filename>meta-yocto-bsp/</filename></title> + + <para> + This directory contains the Yocto Project reference + hardware Board Support Packages (BSPs). + For more information on BSPs, see the + <ulink url='&YOCTO_DOCS_BSP_URL;'>Yocto Project Board Support + Package (BSP) Developer's Guide</ulink>. + </para> + </section> + + <section id='structure-meta-selftest'> + <title><filename>meta-selftest/</filename></title> + + <para> + This directory adds additional recipes and append files + used by the OpenEmbedded selftests to verify the behavior + of the build system. + </para> + + <para> + You do not have to add this layer to your + <filename>bblayers.conf</filename> file unless you want to run the + selftests. + </para> + </section> + + <section id='structure-meta-skeleton'> + <title><filename>meta-skeleton/</filename></title> + + <para> + This directory contains template recipes for BSP and kernel development. + </para> + </section> + + <section id='structure-core-scripts'> + <title><filename>scripts/</filename></title> + + <para> + This directory contains various integration scripts that implement + extra functionality in the Yocto Project environment (e.g. QEMU scripts). + The <link linkend="structure-core-script"><filename>&OE_INIT_FILE;</filename></link> + and + <link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link> + scripts append this directory to the shell's + <filename>PATH</filename> environment variable. + </para> + + <para> + The <filename>scripts</filename> directory has useful scripts that assist in contributing + back to the Yocto Project, such as <filename>create-pull-request</filename> and + <filename>send-pull-request</filename>. + </para> + </section> + + <section id='structure-core-script'> + <title><filename>&OE_INIT_FILE;</filename></title> + + <para> + This script is one of two scripts that set up the OpenEmbedded build + environment. + For information on the other script, see the + "<link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>" + section. + </para> + + <para> + Running this script with the <filename>source</filename> command in + a shell makes changes to <filename>PATH</filename> and sets other + core BitBake variables based on the current working directory. + You need to run an environment setup script before running BitBake + commands. + The script uses other scripts within the + <filename>scripts</filename> directory to do the bulk of the work. + </para> + + <para> + When you run this script, your Yocto Project environment is set + up, a + <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + is created, your working directory becomes the Build Directory, + and you are presented with a list of common BitBake targets. + Here is an example: + <literallayout class='monospaced'> + $ source oe-init-build-env + + ### Shell environment set up for builds. ### + + You can now run 'bitbake <target>' + + Common targets are: + core-image-minimal + core-image-sato + meta-toolchain + meta-ide-support + + You can also run generated qemu images with a command like 'runqemu qemux86' + </literallayout> + The script gets its default list of common targets from the + <filename>conf-notes.txt</filename> file, which is found in the + <filename>meta-poky</filename> directory within the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + Should you have custom distributions, it is very easy to modify + this configuration file to include your targets for your + distribution. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-custom-template-configuration-directory'>Creating a Custom Template Configuration Directory</ulink>" + section in the Yocto Project Development Manual for more + information. + </para> + + <para> + By default, running this script without a + <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + argument creates the <filename>build</filename> directory + in your current working directory. + If you provide a Build Directory argument when you + <filename>source</filename> the script, you direct the OpenEmbedded + build system to create a Build Directory of your choice. + For example, the following command creates a Build Directory named + <filename>mybuilds</filename> that is outside of the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>: + <literallayout class='monospaced'> + $ source &OE_INIT_FILE; ~/mybuilds + </literallayout> + The OpenEmbedded build system uses the template configuration + files, which are found by default in the + <filename>meta-poky/conf</filename> directory in the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-custom-template-configuration-directory'>Creating a Custom Template Configuration Directory</ulink>" + section in the Yocto Project Development Manual for more + information. + <note> + The OpenEmbedded build system does not support file or directory names that + contain spaces. + If you attempt to run the <filename>&OE_INIT_FILE;</filename> script + from a Source Directory that contains spaces in either the filenames + or directory names, the script returns an error indicating no such + file or directory. + Be sure to use a Source Directory free of names containing spaces. + </note> + </para> + </section> + + <section id='structure-memres-core-script'> + <title><filename>oe-init-build-env-memres</filename></title> + + <para> + This script is one of two scripts that set up the OpenEmbedded + build environment. + Aside from setting up the environment, this script starts a + memory-resident BitBake server. + For information on the other setup script, see the + "<link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link>" + section. + </para> + + <para> + Memory-resident BitBake resides in memory until you specifically + remove it using the following BitBake command: + <literallayout class='monospaced'> + $ bitbake -m + </literallayout> + </para> + + <para> + Running this script with the <filename>source</filename> command in + a shell makes changes to <filename>PATH</filename> and sets other + core BitBake variables based on the current working directory. + One of these variables is the + <link linkend='var-BBSERVER'><filename>BBSERVER</filename></link> + variable, which allows the OpenEmbedded build system to locate + the server that is running BitBake. + </para> + + <para> + You need to run an environment setup script before using BitBake + commands. + Following is the script syntax: + <literallayout class='monospaced'> + $ source oe-init-build-env-memres <replaceable>port_number</replaceable> <replaceable>build_dir</replaceable> + </literallayout> + Following are some considerations when sourcing this script: + <itemizedlist> + <listitem><para> + The script uses other scripts within the + <filename>scripts</filename> directory to do the bulk of + the work. + </para></listitem> + <listitem><para> + If you do not provide a port number with the script, the + BitBake server starts at a randomly selected port. + </para></listitem> + <listitem><para> + The script's parameters are positionally dependent. + Consequently, you cannot run the script and provide a + <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + name without also providing a port number. + In other words, the following syntax is illegal: + <literallayout class='monospaced'> + $ source oe-initbuild-env-memres <replaceable>build_dir</replaceable> + </literallayout> + <note> + The previous restriction might be resolved in the + future. + See + <ulink url='https://bugzilla.yoctoproject.org/show_bug.cgi?id=7555'>Bug 7555</ulink> + for more information. + </note> + </para></listitem> + </itemizedlist> + </para> + + <para> + When you run this script, your Yocto Project environment is set + up, a Build Directory is created, your working directory becomes + the Build Directory, and you are presented with a list of common + BitBake targets. + Here is an example: + <literallayout class='monospaced'> + $ source oe-init-build-env-memres + No port specified, using dynamically selected port + + ### Shell environment set up for builds. ### + + You can now run 'bitbake <target>' + + Common targets are: + core-image-minimal + core-image-sato + meta-toolchain + meta-ide-support + + You can also run generated qemu images with a command like 'runqemu qemux86' + Bitbake server address: 127.0.0.1, server port: 53995 + Bitbake server started on demand as needed, use bitbake -m to shut it down + </literallayout> + The script gets its default list of common targets from the + <filename>conf-notes.txt</filename> file, which is found in the + <filename>meta-poky</filename> directory within the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + Should you have custom distributions, it is very easy to modify + this configuration file to include your targets for your + distribution. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-custom-template-configuration-directory'>Creating a Custom Template Configuration Directory</ulink>" + section in the Yocto Project Development Manual for more + information. + </para> + + <para> + By default, running this script without a + <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + argument creates a build directory named + <filename>build</filename>. + If you provide a Build Directory argument and port number when you + <filename>source</filename> the script, the Build Directory is + created using that name. + For example, the following command starts the BitBake server using + port 53995 and creates a Build Directory named + <filename>mybuilds</filename> that is outside of the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>: + <literallayout class='monospaced'> + $ source oe-init-build-env-memres 53995 ~/mybuilds + </literallayout> + The <filename>oe-init-build-env-memres</filename> script starts a + memory resident BitBake server. + This BitBake instance uses the + <filename>bitbake-cookerdaemon.log</filename> file, which is + located in the Build Directory. + </para> + + <para> + The OpenEmbedded build system uses the template configuration + files, which are found by default in the + <filename>meta-poky/conf</filename> directory in the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-custom-template-configuration-directory'>Creating a Custom Template Configuration Directory</ulink>" + section in the Yocto Project Development Manual for more + information. + <note> + The OpenEmbedded build system does not support file or + directory names that contain spaces. + If you attempt to run the + <filename>oe-init-build-env-memres</filename> script + from a Source Directory that contains spaces in either the + filenames or directory names, the script returns an error + indicating no such file or directory. + Be sure to use a Source Directory free of names containing + spaces. + </note> + </para> + </section> + + <section id='structure-basic-top-level'> + <title><filename>LICENSE, README, and README.hardware</filename></title> + + <para> + These files are standard top-level files. + </para> + </section> +</section> + +<section id='structure-build'> + <title>The Build Directory - <filename>build/</filename></title> + + <para> + The OpenEmbedded build system creates the + <ulink url='&YOCTO_DOCS_DEV_URL;#build-directory'>Build Directory</ulink> + when you run one of the build environment setup scripts (i.e. + <link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link> + or + <link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>). + </para> + + <para> + If you do not give the Build Directory a specific name when you run + a setup script, the name defaults to <filename>build</filename>. + </para> + + <para> + The + <link linkend='var-TOPDIR'><filename>TOPDIR</filename></link> variable + points to the Build Directory. + </para> + + <section id='structure-build-buildhistory'> + <title><filename>build/buildhistory</filename></title> + + <para> + The OpenEmbedded build system creates this directory when you + enable the build history feature. + The directory tracks build information into image, packages, and + SDK subdirectories. + For information on the build history feature, see the + "<link linkend='maintaining-build-output-quality'>Maintaining Build Output Quality</link>" + section. + </para> + </section> + + <section id='structure-build-conf-local.conf'> + <title><filename>build/conf/local.conf</filename></title> + + <para> + This configuration file contains all the local user configurations + for your build environment. + The <filename>local.conf</filename> file contains documentation on + the various configuration options. + Any variable set here overrides any variable set elsewhere within + the environment unless that variable is hard-coded within a file + (e.g. by using '=' instead of '?='). + Some variables are hard-coded for various reasons but these + variables are relatively rare. + </para> + + <para> + Edit this file to set the + <filename><link linkend='var-MACHINE'>MACHINE</link></filename> + for which you want to build, which package types you wish to use + (<link linkend='var-PACKAGE_CLASSES'><filename>PACKAGE_CLASSES</filename></link>), + and the location from which you want to access downloaded files + (<filename><link linkend='var-DL_DIR'>DL_DIR</link></filename>). + </para> + + <para> + If <filename>local.conf</filename> is not present when you + start the build, the OpenEmbedded build system creates it from + <filename>local.conf.sample</filename> when + you <filename>source</filename> the top-level build environment + setup script (i.e. + <link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link> + or + <link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>). + </para> + + <para> + The source <filename>local.conf.sample</filename> file used + depends on the <filename>$TEMPLATECONF</filename> script variable, + which defaults to <filename>meta-poky/conf</filename> + when you are building from the Yocto Project development + environment and defaults to <filename>meta/conf</filename> when + you are building from the OpenEmbedded Core environment. + Because the script variable points to the source of the + <filename>local.conf.sample</filename> file, this implies that + you can configure your build environment from any layer by setting + the variable in the top-level build environment setup script as + follows: + <literallayout class='monospaced'> + TEMPLATECONF=<replaceable>your_layer</replaceable>/conf + </literallayout> + Once the build process gets the sample file, it uses + <filename>sed</filename> to substitute final + <filename>${</filename><link linkend='var-OEROOT'><filename>OEROOT</filename></link><filename>}</filename> + values for all <filename>##OEROOT##</filename> values. + <note> + You can see how the <filename>TEMPLATECONF</filename> variable + is used by looking at the + <filename>scripts/oe-setup-builddir</filename> script in the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + You can find the Yocto Project version of the + <filename>local.conf.sample</filename> file in the + <filename>meta-poky/conf</filename> directory. + </note> + </para> + </section> + + <section id='structure-build-conf-bblayers.conf'> + <title><filename>build/conf/bblayers.conf</filename></title> + + <para> + This configuration file defines + <ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>layers</ulink>, + which are directory trees, traversed (or walked) by BitBake. + The <filename>bblayers.conf</filename> file uses the + <link linkend='var-BBLAYERS'><filename>BBLAYERS</filename></link> + variable to list the layers BitBake tries to find. + </para> + + <para> + If <filename>bblayers.conf</filename> is not present when you + start the build, the OpenEmbedded build system creates it from + <filename>bblayers.conf.sample</filename> when + you <filename>source</filename> the top-level build environment + setup script (i.e. + <link linkend='structure-core-script'><filename>&OE_INIT_FILE;</filename></link> + or + <link linkend='structure-memres-core-script'><filename>oe-init-build-env-memres</filename></link>). + </para> + + <para> + The source <filename>bblayers.conf.sample</filename> file used + depends on the <filename>$TEMPLATECONF</filename> script variable, + which defaults to <filename>meta-poky/conf</filename> + when you are building from the Yocto Project development + environment and defaults to <filename>meta/conf</filename> when + you are building from the OpenEmbedded Core environment. + Because the script variable points to the source of the + <filename>bblayers.conf.sample</filename> file, this implies that + you can base your build from any layer by setting the variable in + the top-level build environment setup script as follows: + <literallayout class='monospaced'> + TEMPLATECONF=<replaceable>your_layer</replaceable>/conf + </literallayout> + Once the build process gets the sample file, it uses + <filename>sed</filename> to substitute final + <filename>${</filename><link linkend='var-OEROOT'><filename>OEROOT</filename></link><filename>}</filename> + values for all <filename>##OEROOT##</filename> values. + <note> + You can see how the <filename>TEMPLATECONF</filename> variable + <filename>scripts/oe-setup-builddir</filename> script in the + <ulink url='&YOCTO_DOCS_DEV_URL;#source-directory'>Source Directory</ulink>. + You can find the Yocto Project version of the + <filename>bblayers.conf.sample</filename> file in the + <filename>meta-poky/conf</filename> directory. + </note> + </para> + </section> + + <section id='structure-build-conf-sanity_info'> + <title><filename>build/conf/sanity_info</filename></title> + + <para> + This file indicates the state of the sanity checks and is created + during the build. + </para> + </section> + + <section id='structure-build-downloads'> + <title><filename>build/downloads/</filename></title> + + <para> + This directory contains downloaded upstream source tarballs. + You can reuse the directory for multiple builds or move + the directory to another location. + You can control the location of this directory through the + <filename><link linkend='var-DL_DIR'>DL_DIR</link></filename> variable. + </para> + </section> + + <section id='structure-build-sstate-cache'> + <title><filename>build/sstate-cache/</filename></title> + + <para> + This directory contains the shared state cache. + You can reuse the directory for multiple builds or move + the directory to another location. + You can control the location of this directory through the + <filename><link linkend='var-SSTATE_DIR'>SSTATE_DIR</link></filename> variable. + </para> + </section> + + <section id='structure-build-tmp'> + <title><filename>build/tmp/</filename></title> + + <para> + The OpenEmbedded build system creates and uses this directory + for all the build system's output. + The + <link linkend='var-TMPDIR'><filename>TMPDIR</filename></link> + variable points to this directory. + </para> + + <para> + BitBake creates this directory if it does not exist. + As a last resort, to clean up a build and start it from scratch + (other than the downloads), you can remove everything in the + <filename>tmp</filename> directory or get rid of the + directory completely. + If you do, you should also completely remove the + <filename>build/sstate-cache</filename> directory. + </para> + </section> + + <section id='structure-build-tmp-buildstats'> + <title><filename>build/tmp/buildstats/</filename></title> + + <para> + This directory stores the build statistics. + </para> + </section> + + <section id='structure-build-tmp-cache'> + <title><filename>build/tmp/cache/</filename></title> + + <para> + When BitBake parses the metadata, it creates a cache file of the result that can + be used when subsequently running commands. + BitBake stores these results here on a per-machine basis. + </para> + </section> + + <section id='structure-build-tmp-deploy'> + <title><filename>build/tmp/deploy/</filename></title> + + <para> + This directory contains any "end result" output from the + OpenEmbedded build process. + The <link linkend='var-DEPLOY_DIR'><filename>DEPLOY_DIR</filename></link> + variable points to this directory. + For more detail on the contents of the <filename>deploy</filename> + directory, see the + "<link linkend='images-dev-environment'>Images</link>" and + "<link linkend='sdk-dev-environment'>Application Development SDK</link>" + sections. + </para> + </section> + + <section id='structure-build-tmp-deploy-deb'> + <title><filename>build/tmp/deploy/deb/</filename></title> + + <para> + This directory receives any <filename>.deb</filename> packages produced by + the build process. + The packages are sorted into feeds for different architecture types. + </para> + </section> + + <section id='structure-build-tmp-deploy-rpm'> + <title><filename>build/tmp/deploy/rpm/</filename></title> + + <para> + This directory receives any <filename>.rpm</filename> packages produced by + the build process. + The packages are sorted into feeds for different architecture types. + </para> + </section> + + <section id='structure-build-tmp-deploy-ipk'> + <title><filename>build/tmp/deploy/ipk/</filename></title> + + <para> + This directory receives <filename>.ipk</filename> packages produced by + the build process. + </para> + </section> + + <section id='structure-build-tmp-deploy-licenses'> + <title><filename>build/tmp/deploy/licenses/</filename></title> + + <para> + This directory receives package licensing information. + For example, the directory contains sub-directories for <filename>bash</filename>, + <filename>busybox</filename>, and <filename>glibc</filename> (among others) that in turn + contain appropriate <filename>COPYING</filename> license files with other licensing information. + For information on licensing, see the + "<ulink url='&YOCTO_DOCS_DEV_URL;#maintaining-open-source-license-compliance-during-your-products-lifecycle'>Maintaining Open Source License Compliance During Your Product's Lifecycle</ulink>" + section. + </para> + </section> + + <section id='structure-build-tmp-deploy-images'> + <title><filename>build/tmp/deploy/images/</filename></title> + + <para> + This directory receives complete filesystem images. + If you want to flash the resulting image from a build onto a device, look here for the image. + </para> + + <para> + Be careful when deleting files in this directory. + You can safely delete old images from this directory (e.g. + <filename>core-image-*</filename>). + However, the kernel (<filename>*zImage*</filename>, <filename>*uImage*</filename>, etc.), + bootloader and other supplementary files might be deployed here prior to building an + image. + Because these files are not directly produced from the image, if you + delete them they will not be automatically re-created when you build the image again. + </para> + + <para> + If you do accidentally delete files here, you will need to force them to be + re-created. + In order to do that, you will need to know the target that produced them. + For example, these commands rebuild and re-create the kernel files: + <literallayout class='monospaced'> + $ bitbake -c clean virtual/kernel + $ bitbake virtual/kernel + </literallayout> + </para> + </section> + + <section id='structure-build-tmp-deploy-sdk'> + <title><filename>build/tmp/deploy/sdk/</filename></title> + + <para> + The OpenEmbedded build system creates this directory to hold + toolchain installer scripts, which when executed, install the + sysroot that matches your target hardware. + You can find out more about these installers in the + "<ulink url='&YOCTO_DOCS_SDK_URL;#sdk-building-an-sdk-installer'>Building an SDK Installer</ulink>" + section in the Yocto Project Software Development Kit (SDK) Developer's Guide. + </para> + </section> + + <section id='structure-build-tmp-sstate-control'> + <title><filename>build/tmp/sstate-control/</filename></title> + + <para> + The OpenEmbedded build system uses this directory for the + shared state manifest files. + The shared state code uses these files to record the files + installed by each sstate task so that the files can be removed + when cleaning the recipe or when a newer version is about to + be installed. + The build system also uses the manifests to detect and produce + a warning when files from one task are overwriting those from + another. + </para> + </section> + + <section id='structure-build-tmp-sysroots'> + <title><filename>build/tmp/sysroots/</filename></title> + + <para> + This directory contains shared header files and libraries as well as other shared + data. + Packages that need to share output with other packages do so within this directory. + The directory is subdivided by architecture so multiple builds can run within + the one Build Directory. + </para> + </section> + + <section id='structure-build-tmp-stamps'> + <title><filename>build/tmp/stamps/</filename></title> + + <para> + This directory holds information that BitBake uses for accounting purposes + to track what tasks have run and when they have run. + The directory is sub-divided by architecture, package name, and + version. + Following is an example: + <literallayout class='monospaced'> + stamps/all-poky-linux/distcc-config/1.0-r0.do_build-2fdd....2do + </literallayout> + Although the files in the directory are empty of data, + BitBake uses the filenames and timestamps for tracking purposes. + </para> + </section> + + <section id='structure-build-tmp-log'> + <title><filename>build/tmp/log/</filename></title> + + <para> + This directory contains general logs that are not otherwise placed using the + package's <filename><link linkend='var-WORKDIR'>WORKDIR</link></filename>. + Examples of logs are the output from the + <filename>do_check_pkg</filename> or + <filename>do_distro_check</filename> tasks. + Running a build does not necessarily mean this directory is created. + </para> + </section> + + <section id='structure-build-tmp-work'> + <title><filename>build/tmp/work/</filename></title> + + <para> + This directory contains architecture-specific work sub-directories + for packages built by BitBake. + All tasks execute from the appropriate work directory. + For example, the source for a particular package is unpacked, + patched, configured and compiled all within its own work directory. + Within the work directory, organization is based on the package group + and version for which the source is being compiled + as defined by the + <link linkend='var-WORKDIR'><filename>WORKDIR</filename></link>. + </para> + + <para> + It is worth considering the structure of a typical work directory. + As an example, consider <filename>linux-yocto-kernel-3.0</filename> + on the machine <filename>qemux86</filename> + built within the Yocto Project. + For this package, a work directory of + <filename>tmp/work/qemux86-poky-linux/linux-yocto/3.0+git1+<.....></filename>, + referred to as the + <filename><link linkend='var-WORKDIR'>WORKDIR</link></filename>, is created. + Within this directory, the source is unpacked to + <filename>linux-qemux86-standard-build</filename> and then patched by Quilt. + (See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#using-a-quilt-workflow'>Using Quilt in Your Workflow</ulink>" + section in the Yocto Project Development Manual for more information.) + Within the <filename>linux-qemux86-standard-build</filename> directory, + standard Quilt directories <filename>linux-3.0/patches</filename> + and <filename>linux-3.0/.pc</filename> are created, + and standard Quilt commands can be used. + </para> + + <para> + There are other directories generated within <filename>WORKDIR</filename>. + The most important directory is <filename>WORKDIR/temp/</filename>, + which has log files for each task (<filename>log.do_*.pid</filename>) + and contains the scripts BitBake runs for each task + (<filename>run.do_*.pid</filename>). + The <filename>WORKDIR/image/</filename> directory is where "make + install" places its output that is then split into sub-packages + within <filename>WORKDIR/packages-split/</filename>. + </para> + </section> + + <section id='structure-build-work-shared'> + <title><filename>build/tmp/work-shared/</filename></title> + + <para> + For efficiency, the OpenEmbedded build system creates and uses + this directory to hold recipes that share a work directory with + other recipes. + In practice, this is only used for <filename>gcc</filename> + and its variants (e.g. <filename>gcc-cross</filename>, + <filename>libgcc</filename>, <filename>gcc-runtime</filename>, + and so forth). + </para> + </section> +</section> + +<section id='structure-meta'> + <title>The Metadata - <filename>meta/</filename></title> + + <para> + As mentioned previously, + <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink> is the core + of the Yocto Project. + Metadata has several important subdivisions: + </para> + + <section id='structure-meta-classes'> + <title><filename>meta/classes/</filename></title> + + <para> + This directory contains the <filename>*.bbclass</filename> files. + Class files are used to abstract common code so it can be reused by multiple + packages. + Every package inherits the <filename>base.bbclass</filename> file. + Examples of other important classes are <filename>autotools.bbclass</filename>, which + in theory allows any Autotool-enabled package to work with the Yocto Project with minimal effort. + Another example is <filename>kernel.bbclass</filename> that contains common code and functions + for working with the Linux kernel. + Functions like image generation or packaging also have their specific class files + such as <filename>image.bbclass</filename>, <filename>rootfs_*.bbclass</filename> and + <filename>package*.bbclass</filename>. + </para> + + <para> + For reference information on classes, see the + "<link linkend='ref-classes'>Classes</link>" chapter. + </para> + </section> + + <section id='structure-meta-conf'> + <title><filename>meta/conf/</filename></title> + + <para> + This directory contains the core set of configuration files that start from + <filename>bitbake.conf</filename> and from which all other configuration + files are included. + See the include statements at the end of the + <filename>bitbake.conf</filename> file and you will note that even + <filename>local.conf</filename> is loaded from there. + While <filename>bitbake.conf</filename> sets up the defaults, you can often override + these by using the (<filename>local.conf</filename>) file, machine file or + the distribution configuration file. + </para> + </section> + + <section id='structure-meta-conf-machine'> + <title><filename>meta/conf/machine/</filename></title> + + <para> + This directory contains all the machine configuration files. + If you set <filename>MACHINE = "qemux86"</filename>, + the OpenEmbedded build system looks for a <filename>qemux86.conf</filename> file in this + directory. + The <filename>include</filename> directory contains various data common to multiple machines. + If you want to add support for a new machine to the Yocto Project, look in this directory. + </para> + </section> + + <section id='structure-meta-conf-distro'> + <title><filename>meta/conf/distro/</filename></title> + + <para> + The contents of this directory controls any distribution-specific + configurations. + For the Yocto Project, the <filename>defaultsetup.conf</filename> is the main file here. + This directory includes the versions and the + <filename>SRCDATE</filename> definitions for applications that are configured here. + An example of an alternative configuration might be <filename>poky-bleeding.conf</filename>. + Although this file mainly inherits its configuration from Poky. + </para> + </section> + + <section id='structure-meta-conf-machine-sdk'> + <title><filename>meta/conf/machine-sdk/</filename></title> + + <para> + The OpenEmbedded build system searches this directory for + configuration files that correspond to the value of + <link linkend='var-SDKMACHINE'><filename>SDKMACHINE</filename></link>. + By default, 32-bit and 64-bit x86 files ship with the Yocto + Project that support some SDK hosts. + However, it is possible to extend that support to other SDK hosts + by adding additional configuration files in this subdirectory + within another layer. + </para> + </section> + + <section id='structure-meta-files'> + <title><filename>meta/files/</filename></title> + + <para> + This directory contains common license files and several text files + used by the build system. + The text files contain minimal device information and + lists of files and directories with known permissions. + </para> + </section> + + <section id='structure-meta-lib'> + <title><filename>meta/lib/</filename></title> + + <para> + This directory contains OpenEmbedded Python library code + used during the build process. + </para> + </section> + + <section id='structure-meta-recipes-bsp'> + <title><filename>meta/recipes-bsp/</filename></title> + + <para> + This directory contains anything linking to specific hardware or hardware + configuration information such as "u-boot" and "grub". + </para> + </section> + + <section id='structure-meta-recipes-connectivity'> + <title><filename>meta/recipes-connectivity/</filename></title> + + <para> + This directory contains libraries and applications related to communication with other devices. + </para> + </section> + + <section id='structure-meta-recipes-core'> + <title><filename>meta/recipes-core/</filename></title> + + <para> + This directory contains what is needed to build a basic working Linux image + including commonly used dependencies. + </para> + </section> + + <section id='structure-meta-recipes-devtools'> + <title><filename>meta/recipes-devtools/</filename></title> + + <para> + This directory contains tools that are primarily used by the build system. + The tools, however, can also be used on targets. + </para> + </section> + + <section id='structure-meta-recipes-extended'> + <title><filename>meta/recipes-extended/</filename></title> + + <para> + This directory contains non-essential applications that add features compared to the + alternatives in core. + You might need this directory for full tool functionality or for Linux Standard Base (LSB) + compliance. + </para> + </section> + + <section id='structure-meta-recipes-gnome'> + <title><filename>meta/recipes-gnome/</filename></title> + + <para> + This directory contains all things related to the GTK+ application framework. + </para> + </section> + + <section id='structure-meta-recipes-graphics'> + <title><filename>meta/recipes-graphics/</filename></title> + + <para> + This directory contains X and other graphically related system libraries + </para> + </section> + + <section id='structure-meta-recipes-kernel'> + <title><filename>meta/recipes-kernel/</filename></title> + + <para> + This directory contains the kernel and generic applications and libraries that + have strong kernel dependencies. + </para> + </section> + + <section id='structure-meta-recipes-lsb4'> + <title><filename>meta/recipes-lsb4/</filename></title> + + <para> + This directory contains recipes specifically added to support + the Linux Standard Base (LSB) version 4.x. + </para> + </section> + + <section id='structure-meta-recipes-multimedia'> + <title><filename>meta/recipes-multimedia/</filename></title> + + <para> + This directory contains codecs and support utilities for audio, images and video. + </para> + </section> + + <section id='structure-meta-recipes-rt'> + <title><filename>meta/recipes-rt/</filename></title> + + <para> + This directory contains package and image recipes for using and testing + the <filename>PREEMPT_RT</filename> kernel. + </para> + </section> + + <section id='structure-meta-recipes-sato'> + <title><filename>meta/recipes-sato/</filename></title> + + <para> + This directory contains the Sato demo/reference UI/UX and its associated applications + and configuration data. + </para> + </section> + + <section id='structure-meta-recipes-support'> + <title><filename>meta/recipes-support/</filename></title> + + <para> + This directory contains recipes used by other recipes, but that are + not directly included in images (i.e. dependencies of other + recipes). + </para> + </section> + + <section id='structure-meta-site'> + <title><filename>meta/site/</filename></title> + + <para> + This directory contains a list of cached results for various architectures. + Because certain "autoconf" test results cannot be determined when cross-compiling due to + the tests not able to run on a live system, the information in this directory is + passed to "autoconf" for the various architectures. + </para> + </section> + + <section id='structure-meta-recipes-txt'> + <title><filename>meta/recipes.txt</filename></title> + + <para> + This file is a description of the contents of <filename>recipes-*</filename>. + </para> + </section> +</section> + +</chapter> +<!-- +vim: expandtab tw=80 ts=4 +--> |
