</para>
</section>
+
<section id='usingpoky-extend-addpkg-makefile'>
<title>Makefile-Based Package</title>
<para>
</programlisting>
</section>
+
<section id='usingpoky-extend-addpkg-files'>
<title>Controlling Package Content</title>
<para>
</section>
<section id='usingpoky-extend-customimage-imagefeatures'>
- <title>Customising Images Using Custom <glossterm>
- <link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm></title>
+ <title>Customising Images Using Custom IMAGE_FEATURES</title>
<para>
Ultimately users might want to add extra image "features" as used by Poky with the
<glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm>
dependencies - it only rebuilds the specified package.
</para>
<programlisting>
-bitbake -c clean task-boot task-base task-poky
-bitbake poky-image-sato
+$ bitbake -c clean task-boot task-base task-poky
+$ bitbake poky-image-sato
</programlisting>
</section>
</section>
-<section id="platdev-newmachine">
- <title>Porting Poky to a New Machine</title>
- <para>
- Adding a new machine to Poky is a straightforward process.
- This section provides information that gives you an idea of the changes you must make.
- The information covers adding machines similar to those Poky already supports.
- Although well within the capabilities of Poky, adding a totally new architecture might require
- changes to <filename>gcc/glibc</filename> and to the site information.
- Consequently, the information is beyond the scope of this manual.
- </para>
-
- <section id="platdev-newmachine-conffile">
- <title>Adding the Machine Configuration File</title>
- <para>
- To add a machine configuration you need to add a <filename>.conf</filename> file
- with details of the device being added to <filename>conf/machine/</filename>.
- The name of the file determines the name Poky uses to reference the new machine.
- </para>
+ <section id="platdev-newmachine">
+ <title>Porting Poky to a New Machine</title>
<para>
- The most important variables to set in this file are <glossterm>
- <link linkend='var-TARGET_ARCH'>TARGET_ARCH</link></glossterm>
- (e.g. "arm"), <glossterm><link linkend='var-PREFERRED_PROVIDER'>
- PREFERRED_PROVIDER</link></glossterm>_virtual/kernel (see below) and
- <glossterm><link linkend='var-MACHINE_FEATURES'>MACHINE_FEATURES
- </link></glossterm> (e.g. "kernel26 apm screen wifi").
- You might also need other variables like <glossterm><link linkend='var-SERIAL_CONSOLE'>SERIAL_CONSOLE
- </link></glossterm> (e.g. "115200 ttyS0"), <glossterm>
- <link linkend='var-KERNEL_IMAGETYPE'>KERNEL_IMAGETYPE</link>
- </glossterm> (e.g. "zImage") and <glossterm><link linkend='var-IMAGE_FSTYPES'>
- IMAGE_FSTYPES</link></glossterm> (e.g. "tar.gz jffs2").
- You can find full details on these variables in the reference section.
- You can leverage many existing machine <filename>.conf</filename> files from
- <filename>meta/conf/machine/</filename>.
+ Adding a new machine to Poky is a straightforward process.
+ This section provides information that gives you an idea of the changes you must make.
+ The information covers adding machines similar to those Poky already supports.
+ Although well within the capabilities of Poky, adding a totally new architecture might require
+ changes to <filename>gcc/glibc</filename> and to the site information.
+ Consequently, the information is beyond the scope of this manual.
</para>
- </section>
- <section id="platdev-newmachine-kernel">
- <title>Adding a Kernel for the Machine</title>
- <para>
- Poky needs to be able to build a kernel for the machine.
- You need to either create a new kernel recipe for this machine, or extend an
- existing recipe.
- You can find several kernel examples in the <filename>meta/recipes-kernel/linux</filename>
- directory that can be used as references.
- </para>
- <para>
- If you are creating a new recipe, the "normal" recipe-writing rules apply for setting
- up a <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm>.
- This means specifying any necessary patches and setting <glossterm>
- <link linkend='var-S'>S</link></glossterm> to point at the source code.
- You need to create a "configure" task that configures the unpacked kernel with a defconfig.
- You can do this by using a <filename>make defconfig</filename> command or
- more commonly by copying in a suitable defconfig and and then running
- <filename>make oldconfig</filename>.
- By making use of "inherit kernel" and potentially some of the
- <filename>linux-*.inc</filename> files, most other functionality is
- centralized and the the defaults of the class normally work well.
- </para>
- <para>
- If you are extending an existing kernel, it is usually a matter of adding a
- suitable <filename>defconfig</filename> file.
- The file needs to be added into a location similar to <filename>defconfig</filename> files
- used for other machines in a given kernel.
- A possible way to do this is by listing the file in the
- <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm>
- and adding the machine to the expression in
- <glossterm><link linkend='var-COMPATIBLE_MACHINE'>COMPATIBLE_MACHINE</link></glossterm>:
- </para>
- <programlisting>
+ <section id="platdev-newmachine-conffile">
+ <title>Adding the Machine Configuration File</title>
+ <para>
+ To add a machine configuration you need to add a <filename>.conf</filename> file
+ with details of the device being added to <filename>conf/machine/</filename>.
+ The name of the file determines the name Poky uses to reference the new machine.
+ </para>
+ <para>
+ The most important variables to set in this file are <glossterm>
+ <link linkend='var-TARGET_ARCH'>TARGET_ARCH</link></glossterm>
+ (e.g. "arm"), <glossterm><link linkend='var-PREFERRED_PROVIDER'>
+ PREFERRED_PROVIDER</link></glossterm>_virtual/kernel (see below) and
+ <glossterm><link linkend='var-MACHINE_FEATURES'>MACHINE_FEATURES
+ </link></glossterm> (e.g. "kernel26 apm screen wifi").
+ You might also need other variables like <glossterm><link linkend='var-SERIAL_CONSOLE'>SERIAL_CONSOLE
+ </link></glossterm> (e.g. "115200 ttyS0"), <glossterm>
+ <link linkend='var-KERNEL_IMAGETYPE'>KERNEL_IMAGETYPE</link>
+ </glossterm> (e.g. "zImage") and <glossterm><link linkend='var-IMAGE_FSTYPES'>
+ IMAGE_FSTYPES</link></glossterm> (e.g. "tar.gz jffs2").
+ You can find full details on these variables in the reference section.
+ You can leverage many existing machine <filename>.conf</filename> files from
+ <filename>meta/conf/machine/</filename>.
+ </para>
+ </section>
+
+ <section id="platdev-newmachine-kernel">
+ <title>Adding a Kernel for the Machine</title>
+ <para>
+ Poky needs to be able to build a kernel for the machine.
+ You need to either create a new kernel recipe for this machine, or extend an
+ existing recipe.
+ You can find several kernel examples in the <filename>meta/recipes-kernel/linux</filename>
+ directory that can be used as references.
+ </para>
+ <para>
+ If you are creating a new recipe, the "normal" recipe-writing rules apply for setting
+ up a <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm>.
+ This means specifying any necessary patches and setting <glossterm>
+ <link linkend='var-S'>S</link></glossterm> to point at the source code.
+ You need to create a "configure" task that configures the unpacked kernel with a defconfig.
+ You can do this by using a <filename>make defconfig</filename> command or
+ more commonly by copying in a suitable defconfig and and then running
+ <filename>make oldconfig</filename>.
+ By making use of "inherit kernel" and potentially some of the
+ <filename>linux-*.inc</filename> files, most other functionality is
+ centralized and the the defaults of the class normally work well.
+ </para>
+ <para>
+ If you are extending an existing kernel, it is usually a matter of adding a
+ suitable <filename>defconfig</filename> file.
+ The file needs to be added into a location similar to <filename>defconfig</filename> files
+ used for other machines in a given kernel.
+ A possible way to do this is by listing the file in the
+ <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm>
+ and adding the machine to the expression in
+ <glossterm><link linkend='var-COMPATIBLE_MACHINE'>COMPATIBLE_MACHINE</link></glossterm>:
+ </para>
+ <programlisting>
COMPATIBLE_MACHINE = '(qemux86|qemumips)'
- </programlisting>
- </section>
+ </programlisting>
+ </section>
- <section id="platdev-newmachine-formfactor">
- <title>Adding a Formfactor Configuration File</title>
- <para>
- A formfactor configuration file provides information about the
- target hardware on which Poky is running, and that Poky cannot
- obtain from other sources such as the kernel. Some examples of
- information contained in a formfactor configuration file include
- framebuffer orientation, whether or not the system has a keyboard,
- the positioning of the keyboard in relation to the screen, and
- screen resolution.
- </para>
- <para>
- Sane defaults should be used in most cases, but if customisation is
- necessary you need to create a <filename>machconfig</filename> file
- under <filename>meta/packages/formfactor/files/MACHINENAME/</filename>
- where <literal>MACHINENAME</literal> is the name for which this infomation
- applies. For information about the settings available and the defaults, please see
- <filename>meta/packages/formfactor/files/config</filename>. Below is one
- example for qemuarm:
- </para>
- <programlisting>
+ <section id="platdev-newmachine-formfactor">
+ <title>Adding a Formfactor Configuration File</title>
+ <para>
+ A formfactor configuration file provides information about the
+ target hardware on which Poky is running, and that Poky cannot
+ obtain from other sources such as the kernel.
+ Some examples of information contained in a formfactor configuration file include
+ framebuffer orientation, whether or not the system has a keyboard,
+ the positioning of the keyboard in relation to the screen, and
+ screen resolution.
+ </para>
+ <para>
+ Reasonable defaults are used in most cases, but if customization is
+ necessary you need to create a <filename>machconfig</filename> file
+ under <filename>meta/packages/formfactor/files/MACHINENAME/</filename>,
+ where <literal>MACHINENAME</literal> is the name for which this infomation
+ applies.
+ For information about the settings available and the defaults, see
+ <filename>meta/packages/formfactor/files/config</filename>.
+ Following is an example for qemuarm:
+ </para>
+ <programlisting>
HAVE_TOUCHSCREEN=1
HAVE_KEYBOARD=1
#DISPLAY_BPP=16
DISPLAY_DPI=150
DISPLAY_SUBPIXEL_ORDER=vrgb
- </programlisting>
+ </programlisting>
+ </section>
</section>
-</section>
-<section id='usingpoky-changes'>
+ <section id="usingpoky-changes">
<title>Making and Maintaining Changes</title>
-
<para>
- We recognise that people will want to extend/configure/optimise Poky for
- their specific uses, especially due to the extreme configurability and
- flexibility Poky offers. To ensure ease of keeping pace with future
- changes in Poky we recommend making changes to Poky in a controlled way.
+ Because Poky offers extreme configurability and fliexibility, we recognize that people will want
+ to extend, configure or optimise Poky for their specific uses.
+ To best keep pace with future Poky changes we recommend you make controlled changes to Poky.
</para>
<para>
- Poky supports the idea of <link
- linkend='usingpoky-changes-layers'>"layers"</link> which when used
- properly can massively ease future upgrades and allow segregation
- between the Poky core and a given developer's changes. Some other advice on
- managing changes to Poky is also given in the following section.
+ Poky supports the idea of <link linkend='usingpoky-changes-layers'>"layers"</link>.
+ If you use layers properly you can ease future upgrades and allow segregation
+ between the Poky core and a given developer's changes.
+ The following section provides more advice on managing changes to Poky.
</para>
<section id="usingpoky-changes-layers">
<title>Bitbake Layers</title>
-
<para>
- Often, people want to extend Poky either through adding packages
- or overriding files contained within Poky to add their own
- functionality. Bitbake has a powerful mechanism called
- layers which provides a way to handle this extension in a fully
+ Often, people want to extend Poky either by adding packages
+ or by overriding files contained within Poky to add their own
+ functionality.
+ Bitbake has a powerful mechanism called
+ "layers", which provides a way to handle this extension in a fully
supported and non-invasive fashion.
</para>
-
<para>
- The Poky tree includes several additional layers which demonstrate
- this functionality, such as meta-emenlow and meta-extras.
- The meta-emenlow layer is an example layer enabled by default. The meta-extras
- repostory is not enabled by default but enabling any layer is as easy as adding
- the layers path to the BBLAYERS variable in your bblayers.conf. this is how
- meta-extras are enabled in Poky builds:
+ The Poky tree includes several additional layers such as meta-emenlow and meta-extras
+ that demonstrate this functionality.
+ The meta-emenlow layer is an example layer that by default is enabled.
+ However, the meta-extras repostory is not enabled by default.
+ It is easy though to enable any layer.
+ You simply add the layer's path to the
+ <glossterm><link linkend='var-BBLAYERS'>BBLAYERS</link></glossterm> variable in your
+ <filename>bblayers.conf</filename> file.
+ The following example shows how to enable meta-extras in the Poky build:
</para>
<para>
<literallayout class='monospaced'>LCONF_VERSION = "1"
</para>
<para>
- Bitbake parses the conf/layer.conf of each of the layers in BBLAYERS
- to add the recipes, classes and configuration contained within the layer to Poky.
+ Bitbake parses each <filename>conf/layer.conf</filename> file for each layer in BBLAYERS
+ and adds the recipes, classes and configuration contained within the layer to Poky.
To create your own layer, independent of the main Poky repository,
- you need only create a directory with a conf/layer.conf file and
- add the directory to your bblayers.conf.
+ simply create a directory with a <filename>conf/layer.conf</filename> file and
+ add the directory to your <filename>bblayers.conf</filename> file.
</para>
-
<para>
- The meta-emenlow/conf/layer.conf demonstrates the required syntax:
+ The <filename>meta-emenlow/conf/layer.conf</filename> file demonstrates the required syntax:
<literallayout class='monospaced'># We have a conf and classes directory, add to BBPATH
BBPATH := "${BBPATH}:${LAYERDIR}"
BBFILE_PRIORITY_emenlow = "6"
</literallayout>
</para>
-
<para>
- As can be seen, the layers recipes are added to
- <glossterm> <link linkend='var-BBFILES'>BBFILES</link></glossterm>. The
- BBFILE_COLLECTIONS variable is then appended to with the
- layer name. The BBFILE_PATTERN variable is immediately expanded
- with a regular expression used to match files from BBFILES into
+ In the previous example, the recipes for the layers are added to
+ <glossterm> <link linkend='var-BBFILES'>BBFILES</link></glossterm>.
+ The <glossterm><link linkend='var-BBFILE_COLLECTIONS'>BBFILE_COLLECTIONS</link></glossterm>
+ variable is then appended with the layer name.
+ The <glossterm><link linkend='var-BBFILE_PATTERN'>BBFILE_PATTERN</link></glossterm> variable
+ immediately expands with a regular expression used to match files from BBFILES into
a particular layer, in this case by using the base pathname.
- The BBFILE_PRIORITY variable then assigns different
- priorities to the files in different layers. This is useful
- in situations where the same package might appear in multiple
- layers and allows you to choose which layer should 'win'.
- Note the use of <glossterm><link linkend='var-LAYERDIR'>
- LAYERDIR</link></glossterm> with the immediate expansion operator.
- <glossterm><link linkend='var-LAYERDIR'>LAYERDIR</link></glossterm>
- expands to the directory of the current layer and
- requires use of the immediate expansion operator so that Bitbake
- does not lazily expand the variable when it's parsing a
- different directory.
- </para>
-
- <para>
- Additional bbclass and configuration files can be locationed by
- bitbake through the addition to the BBPATH
- environment variable. In this case, the first file with the
- matching name found in BBPATH is the one that is used, just
- like the PATH variable for binaries. It is therefore recommended
- that you use unique bbclass and configuration file names in your
+ The <glossterm><link linkend='var-BBFILE_PRIORITY'>BBFILE_PRIORITY</link></glossterm> variable
+ then assigns different priorities to the files in different layers.
+ This technique useful in situations where the same package might appear in multiple
+ layers and allows you to choose what layer should take precedence.
+ </para>
+ <para>
+ Note the use of the <glossterm><link linkend='var-LAYERDIR'>LAYERDIR</link></glossterm>
+ variable with the immediate expansion operator.
+ The LAYERDIR variable expands to the directory of the current layer and
+ requires the immediate expansion operator so that Bitbake does not wait to expand the variable
+ when it's parsing a different directory.
+ </para>
+ <para>
+ Bitbake can locate where other bbclass and configuration files are applied through
+ the <glossterm><link linkend='var-BBPATH'>BBPATH</link></glossterm>
+ environment variable.
+ For these cases, Bitake uses the first file with the matching name found in BBPATH.
+ This is similar to the way the PATH variable is used for binaries.
+ We recommend, therefore, that you use unique bbclass and configuration file names in your
custom layer.
</para>
-
<para>
- The recommended approach for custom layers is to store them in a
- git repository of the format meta-prvt-XXXX and have this repository
- cloned alongside the other meta directories in the Poky tree.
- This way you can keep your Poky tree and it's configuration entirely
+ We also recommend the following:
+ <itemizedlist>
+ <listitem><para>Store custom layers in a git repository that uses the
+ meta-prvt-XXXX format.</para></listitem>
+ <listitem><para>Clone the repository alongside other meta directories in the Poky
+ tree.</para></listitem>
+ </itemizedlist>
+ Following these recommendations keeps your Poky tree and its configuration entirely
inside POKYBASE.
</para>
</section>
- <section id='usingpoky-changes-commits'>
+ <section id="usingpoky-changes-commits">
<title>Committing Changes</title>
-
<para>
Modifications to Poky are often managed under some kind of source
- revision control system. The policy for committing to such systems
- is important as some simple policy can significantly improve
- usability. The tips below are based on the policy followed for the
- Poky core.
+ revision control system.
+ Because some simple practices can significantly improve usability, policy for committing changes
+ is important.
+ Following are suggestions for committing changes to the Poky core:
</para>
-
<para>
- It helps to use a consistent style for commit messages when committing
- changes. We've found a style where the first line of a commit message
- summarises the change and starts with the name of any package affected
- work well. Not all changes are to specific packages so the prefix could
- also be a machine name or class name instead. If a change needs a longer
- description this should follow the summary:
+ It helps to use a consistent documentation style when committing changes.
+ We have found the following style works well.
+ <itemizedlist>
+ <listitem><para>The first line of the commit summarizes the change and begins with the
+ name of the affected package or packages.
+ However, not all changes apply to specific packages.
+ Consequently, the prefix could also be a machine name or class name for
+ example.</para></listitem>
+ <listitem><para>The second part of the commit (if needed) is a longer more detailed
+ description of the changes. Placing a blank line between the first and second parts
+ helps with readability.</para></listitem>
+ </itemizedlist>
+ </para>
+ <para>
+ Following is an example commit:
</para>
-
<literallayout class='monospaced'>
bitbake/data.py: Add emit_func() and generate_dependencies() functions
</literallayout>
<para>
- Any commit should be self contained in that it should leave the
- metadata in a consistent state, buildable before and after the
- commit. This helps ensure the autobuilder test results are valid
- but is good practice regardless.
+ All commits should be self-contained such that they leave the
+ metadata in a consistent state that builds both before and after the
+ commit is made.
+ Besides being a good policy to follow, this helps ensure the autobuilder test results
+ are valid.
</para>
</section>
- <section id='usingpoky-changes-prbump'>
+ <section id="usingpoky-changes-prbump">
<title>Package Revision Incrementing</title>
-
<para>
- If a committed change will result in changing the package output
+ If a committed change results in changing the package output
then the value of the <glossterm><link linkend='var-PR'>PR</link>
- </glossterm> variable needs to be increased (commonly referred to
- as 'bumped') as part of that commit. Only integer values are used
- and <glossterm><link linkend='var-PR'>PR</link></glossterm> =
- "r0" should be added into new recipes as, while this is the
- default value, not having the variable defined in a recipe makes
- it easy to miss incrementing it when updating the recipe.
- When upgrading the version of a package (<glossterm><link
- linkend='var-PV'>PV</link></glossterm>), the <glossterm><link
- linkend='var-PR'>PR</link></glossterm> variable should be reset to "r0".
+ </glossterm> variable needs to be increased ('bumped') as part of that commit.
+ This means that for new recipes you be sure to add the PR variable and set its initial value
+ equal to "r0".
+ Not initially defining PR makes makes it easy to miss when you bump a package.
+ Note that you can only use integer values for the PR variable.
+ </para>
+ <para>
+ When upgrading the version of a package the (<glossterm><link
+ linkend='var-PV'>PV</link></glossterm>) and PR variables should be reset to "r0".
</para>
-
<para>
- The aim is that the package version will only ever increase. If
- for some reason <glossterm><link linkend='var-PV'>PV</link></glossterm>
- will change and but not increase, the <glossterm><link
- linkend='var-PE'>PE</link></glossterm> (Package Epoch) can
- be increased (it defaults to '0'). The version numbers aim to
- follow the <ulink url='http://www.debian.org/doc/debian-policy/ch-controlfields.html'>
- Debian Version Field Policy Guidelines</ulink> which define how
- versions are compared and hence what "increasing" means.
+ Usually a package version only increases.
+ However, if for some reason PV changes but does not increase, you can increase the
+ <glossterm><link linkend='var-PE'>PE</link></glossterm> variable (Package Epoch).
+ The PE variable defaults to '0'.
+ </para>
+ <para>
+ Version numbering strives to follow the
+ <ulink url='http://www.debian.org/doc/debian-policy/ch-controlfields.html'>
+ Debian Version Field Policy Guidelines</ulink>.
+ These guidelines define how versions are compared and what "increasing" a version means.
</para>
-
<para>
- There are two reasons for doing this, the first is to ensure that
- when a developer updates and rebuilds, they get all the changes to
+ There are two reasons for following these guidelines.
+ First, to ensure that when a developer updates and rebuilds, they get all the changes to
the repository and don't have to remember to rebuild any sections.
- The second is to ensure that target users are able to upgrade their
- devices via their package manager such as with the <command>
- opkg upgrade</command> commands (or similar for
- dpkg/apt or rpm based systems). The aim is to ensure Poky has
- upgradable packages in all cases.
+ Second, to ensure that target users are able to upgrade their
+ devices using package manager commands such as <filename>
+ opkg upgrade</filename> (or similar commands for dpkg/apt or rpm-based systems).
+ </para>
+ <para>
+ The goal is to ensure Poky has upgradable packages in all cases.
</para>
</section>
- <section id='usingpoky-changes-collaborate'>
- <title>Using Poky in a Team Environment</title>
+ <section id="usingpoky-changes-collaborate">
+ <title>Using Poky in a Team Environment</title>
<para>
- It may not be immediately clear how Poky can work in a team environment,
- or scale to a large team of developers. The specifics of any situation
- will determine the best solution and poky offers immense flexibility in
- that aspect but there are some practises that experience has shown to work
- well.
+ It may not be immediately clear how you can use Poky in a team environment,
+ or scale it for a large team of developers.
+ The specifics of any situation determine the best solution.
+ Granted that Poky offers immense flexibility regarding this, practices do exist
+ that experience has shown work well.
</para>
-
<para>
The core component of any development effort with Poky is often an
- automated build testing framework and image generation process. This
- can be used to check that the metadata is buildable, highlight when
- commits break the builds and provide up to date images allowing people
- to test the end result and use them as a base platform for further
- development. Experience shows that buildbot is a good fit for this role
- and that it works well to configure it to make two types of build -
- incremental builds and 'from scratch'/full builds. The incremental builds
- can be tied to a commit hook which triggers them each time a commit is
- made to the metadata and are a useful acid test of whether a given commit
- breaks the build in some serious way. They catch lots of simple errors
- and whilst they won't catch 100% of failures, the tests are fast so
- developers can get feedback on their changes quickly. The full builds
- are builds that build everything from the ground up and test everything.
- They usually happen at preset times such as at night when the machine
- load isn't high from the incremental builds.
- <ulink url='http://autobuilder.pokylinux.org:8010'>poky autobuilder</ulink>
- is an example implementation with buildbot.
- </para>
-
- <para>
- Most teams have pieces of software undergoing active development. It is of
- significant benefit to put these under control of a source control system
- compatible with Poky such as git or svn. The autobuilder can then be set to
- pull the latest revisions of these packages so the latest commits get tested
- by the builds allowing any issues to be highlighted quickly. Poky easily
- supports configurations where there is both a stable known good revision
- and a floating revision to test. Poky can also only take changes from specific
- source control branches giving another way it can be used to track/test only
- specified changes.
- </para>
- <para>
- Perhaps the hardest part of setting this up is the policy that surrounds
- the different source control systems, be them software projects or the Poky
- metadata itself. The circumstances will be different in each case but this is
- one of Poky's advantages - the system itself doesn't force any particular policy
- unlike a lot of build systems, allowing the best policy to be chosen for the
- circumstances.
+ automated build testing framework and an image generation process.
+ You can use these core components to check that the metadata is buildable,
+ highlight when commits break the builds, and provide up-to-date images that
+ allow people to test the end result and use it as a base platform for further
+ development.
+ Experience shows that buildbot is a good fit for this role.
+ What works well is to configure buildbot to make two types of builds:
+ incremental and full (from scratch).
+ See <ulink url='http://autobuilder.pokylinux.org:8010'>poky autobuilder</ulink>
+ for an example implementation that uses buildbot.
+ </para>
+ <para>
+ You can tie incremental builds to a commit hook that triggers the build
+ each time a commit is made to the metadata.
+ This practice results in useful acid tests that determine whether a given commit
+ breaks the build in some serious way.
+ Associating a build to a commit can catch a lot of simple errors.
+ Furthermore, the tests are fast so developers can get quick feedback on changes.
+ </para>
+ <para>
+ Full builds build and test everything from the ground up.
+ They usually happen at preset times like during the night when the machine
+ load is low.
+ </para>
+ <para>
+ Most teams have many pieces of software undergoing active development at any given time.
+ You can derive large benefits by putting these pieces under the control of a source
+ control system that is compatible with Poky (i.e. git or svn).
+ You can then set the autobuilder to pull the latest revisions of the packages
+ and test the latest commits by the builds.
+ This practice quickly highlights issues.
+ Poky easily supports testing configurations that use both a stable known good revision
+ and a floating revision.
+ Poky can also take just the changes from specific source control branches.
+ This capability allows you to track and test specific changes.
+ </para>
+ <para>
+ Perhaps the hardest part of setting this up is defining the software project or
+ Poky metadata policies that surround the different source control systems.
+ Of course circumstances will be different in each case.
+ However, this situation reveals one of Poky's advantages - the system itself does not
+ force any particular policy on users, unlike a lot of build systems.
+ The system allows the best policy to be chosen for the given circumstances.
</para>
</section>
- <section id='usingpoky-changes-updatingimages'>
+ <section id="usingpoky-changes-updatingimages">
<title>Updating Existing Images</title>
-
<para>
Often, rather than reflashing a new image you might wish to install updated
- packages into an existing running system. This can be done by sharing the <filename class="directory">tmp/deploy/ipk/</filename> directory through a web server and then on the device, changing <filename>/etc/opkg/base-feeds.conf</filename> to point at this server, for example by adding:
+ packages into an existing running system.
+ You can do this by first sharing the
+ <filename class="directory">tmp/deploy/ipk/</filename> directory
+ through a web server and then by changing <filename>/etc/opkg/base-feeds.conf</filename>
+ to point at the shared server.
+ Following is an example:
</para>
<literallayout class='monospaced'>
src/gz all http://www.mysite.com/somedir/deploy/ipk/all
</section>
</section>
- <section id='usingpoky-modifing-packages'>
+ <section id="usingpoky-modifing-packages">
<title>Modifying Package Source Code</title>
-
<para>
- Poky is usually used to build software rather than modifying
- it. However, there are ways Poky can be used to modify software.
+ Although Poky is usually used to build software, you can use it to modify software.
</para>
-
<para>
- During building, the sources are available in <glossterm><link
- linkend='var-WORKDIR'>WORKDIR</link></glossterm> directory.
- Where exactly this is depends on the type of package and the
- architecture of target device. For a standard recipe not
- related to <glossterm><link
- linkend='var-MACHINE'>MACHINE</link></glossterm> it will be
+ During building, source is available in the
+ <glossterm><link linkend='var-WORKDIR'>WORKDIR</link></glossterm> directory.
+ The actual location depends on the type of package and the architecture of the target device.
+ For a standard recipe not related to
+ <glossterm><link linkend='var-MACHINE'>MACHINE</link></glossterm> the location is
<filename>tmp/work/PACKAGE_ARCH-poky-TARGET_OS/PN-PV-PR/</filename>.
- Target device dependent packages use <glossterm><link
- linkend='var-MACHINE'>MACHINE
- </link></glossterm>
- instead of <glossterm><link linkend='var-PACKAGE_ARCH'>PACKAGE_ARCH
- </link></glossterm>
+ For target device-dependent packages you should use the MACHINE variable instead of
+ <glossterm><link linkend='var-PACKAGE_ARCH'>PACKAGE_ARCH</link></glossterm>
in the directory name.
</para>
-
<tip>
<para>
- Check the package recipe sets the <glossterm><link
- linkend='var-S'>S</link></glossterm> variable to something
- other than standard <filename>WORKDIR/PN-PV/</filename> value.
+ Be sure the package recipe sets the
+ <glossterm><link linkend='var-S'>S</link></glossterm> variable to something
+ other than standard <filename>WORKDIR/PN-PV/</filename> value.
</para>
</tip>
<para>
- After building a package, a user can modify the package source code
- without problem. The easiest way to test changes is by calling the
- "compile" task:
+ After building a package, you can modify the package source code without problems.
+ The easiest way to test your changes is by calling the "compile" task as shown in the
+ following example:
</para>
<programlisting>
</programlisting>
<para>
- "-f" or "--force" is used to force re-execution of the specified task.
- Other tasks may also be called this way. But note that all the modifications
- in <glossterm><link linkend='var-WORKDIR'>WORKDIR</link></glossterm>
- are gone once you executes "-c clean" for a package.
+ The "-f" or "--force" option forces re-execution of the specified task.
+ You can call other tasks this way as well.
+ But note that all the modifications in
+ <glossterm><link linkend='var-WORKDIR'>WORKDIR</link></glossterm>
+ are gone once you execute "-c clean" for a package.
</para>
- <section id='usingpoky-modifying-packages-quilt'>
+ <section id="usingpoky-modifying-packages-quilt">
<title>Modifying Package Source Code with quilt</title>
-
<para>
- By default Poky uses <ulink
- url='http://savannah.nongnu.org/projects/quilt'>quilt</ulink>
- to manage patches in <function>do_patch</function> task.
- It is a powerful tool which can be used to track all
- modifications done to package sources.
+ By default Poky uses <ulink url='http://savannah.nongnu.org/projects/quilt'>quilt</ulink>
+ to manage patches in the <filename>do_patch</filename> task.
+ This is a powerful tool that you can use to track all modifications to package sources.
</para>
-
<para>
- Before modifying source code it is important to
- notify quilt so it will track changes into new patch
- file:
+ Before modifying source code, it is important to notify quilt so it can track the changes
+ into the new patch file:
+
<programlisting>
quilt new NAME-OF-PATCH.patch
</programlisting>
- Then add all files which will be modified into that
- patch:
+ After notifying quilt, add all modified files into that patch:
<programlisting>
quilt add file1 file2 file3
</programlisting>
- Now start editing. At the end quilt needs to be used
- to generate final patch which will contain all
- modifications:
+ You can now start editing.
+ Once you are done editing, you need to use quilt to generate the final patch that
+ will contain all your modifications.
<programlisting>
quilt refresh
</programlisting>
- The resulting patch file can be found in the
+ You can find the resulting patch file in the
<filename class="directory">patches/</filename> subdirectory of the source
- (<glossterm><link linkend='var-S'>S</link></glossterm>) directory. For future builds it
- should be copied into
- Poky metadata and added into <glossterm><link
- linkend='var-SRC_URI'>SRC_URI</link></glossterm> of a recipe:
+ (<glossterm><link linkend='var-S'>S</link></glossterm>) directory.
+ For future builds you should copy the patch into Poky metadata and add it into the
+ <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm> of a recipe.
+ Here is an example:
<programlisting>
SRC_URI += "file://NAME-OF-PATCH.patch"
</programlisting>
-
- This also requires a bump of <glossterm><link
- linkend='var-PR'>PR</link></glossterm> value in the same recipe as we changed resulting packages.
+ Finally, don't forget to 'bump' the
+ <glossterm><link linkend='var-PR'>PR</link></glossterm> value in the same recipe.
+ The resulting packages have changed.
</para>
-
</section>
</section>
- <section id='usingpoky-configuring-LIC_FILES_CHKSUM'>
- <title>Track license change</title>
+
+ <section id="usingpoky-configuring-LIC_FILES_CHKSUM">
+ <title>Track License Change</title>
<para>
- The license of one upstream project may change in the future, and Poky provides
- one mechanism to track such license change - <glossterm>
- <link linkend='var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</link></glossterm> variable.
+ The license of an upstream project might change in the future.
+ To address this situation, Poky uses the
+ <glossterm><link linkend='var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</link></glossterm> variable
+ to track license changes.
</para>
- <section id='usingpoky-specifying-LIC_FILES_CHKSUM'>
- <title>Specifying the LIC_FILES_CHKSUM variable </title>
-
+ <section id="usingpoky-specifying-LIC_FILES_CHKSUM">
+ <title>Specifying the LIC_FILES_CHKSUM Variable </title>
+ <para>
+ The <glossterm><link linkend='var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</link></glossterm>
+ variable contains checksums of the license text in the recipe source code.
+ Poky uses this to track changes in the license text of the source code files.
+ Following is an example of LIC_FILES_CHKSUM:
+ </para>
<programlisting>
LIC_FILES_CHKSUM = "file://COPYING; md5=xxxx \
file://licfile1.txt; beginline=5; endline=29;md5=yyyy \
file://licfile2.txt; endline=50;md5=zzzz \
..."
</programlisting>
-
<para>
- <glossterm><link linkend='var-S'>S</link></glossterm> is the default directory
- for searching files listed in <glossterm><link linkend='var-LIC_FILES_CHKSUM'>
- LIC_FILES_CHKSUM</link></glossterm>. Relative path could be used too:
+ Poky uses the <glossterm><link linkend='var-S'>S</link></glossterm> variable as the
+ default directory used when searching files listed in LIC_FILES_CHKSUM.
+ The previous example employs the default directory.
+ </para>
+ <para>
+ You can also use relative paths as shown in the following example:
</para>
-
<programlisting>
LIC_FILES_CHKSUM = "file://src/ls.c;startline=5;endline=16;\
md5=bb14ed3c4cda583abc85401304b5cd4e"
LIC_FILES_CHKSUM = "file://../license.html;md5=5c94767cedb5d6987c902ac850ded2c6"
</programlisting>
-
<para>
- The first line locates a file in <glossterm><link linkend='var-S'>
- S</link></glossterm>/src/ls.c, and the second line refers to a file in
- <glossterm><link linkend='var-WORKDIR'>WORKDIR</link></glossterm>, which is the parent
- of <glossterm><link linkend='var-S'>S</link></glossterm>
+ In this example the first line locates a file in
+ <glossterm><link linkend='var-S'>S</link></glossterm><filename>/src/ls.c</filename>.
+ The second line refers to a file in
+ <glossterm><link linkend='var-WORKDIR'>WORKDIR</link></glossterm>, which is the parent
+ of <glossterm><link linkend='var-S'>S</link></glossterm>.
</para>
-
</section>
- <section id='usingpoky-LIC_FILES_CHKSUM-explanation-of-syntax'>
- <title>Explanation of syntax</title>
-
+ <section id="usingpoky-LIC_FILES_CHKSUM-explanation-of-syntax">
+ <title>Explanation of Syntax</title>
<para>
- This parameter lists all the important files containing the text
-of licenses for the
-source code. It is also possible to specify on which line the license text
-starts and on which line it ends within that file using the "beginline" and
-"endline" parameters. If the "beginline" parameter is not specified then license
-text begins from the 1st line is assumed. Similarly if "endline" parameter is
-not specified then the license text ends at the last line in the file is
-assumed. So if a file contains only licensing information, then there is no need
-to specify "beginline" and "endline" parameters.
+ As mentioned in the previous section the LIC_FILES_CHKSUM variable lists all the
+ important files that contain the license text for the source code.
+ Using this variable you can specify the line on which the license text starts and ends
+ by supplyiing "beginline" and "endline" parameters.
+ If you do not use the "beginline" parameter then it is assumed that the text begins on the
+ first line of the file.
+ Similarly, if you do not use the "endline" parameter it is assumed that the license text
+ ends as the last line of the file.
</para>
<para>
-The "md5" parameter stores the md5 checksum of the license text. So if
-the license text changes in any way from a file, then its md5 sum will differ and will not
-match with the previously stored md5 checksum. This mismatch will trigger build
-failure, notifying developer about the license text md5 mismatch, and allowing
-the developer to review the license text changes. Also note that if md5 checksum
-is not matched while building, the correct md5 checksum is printed in the build
-log which can be easily copied to .bb file.
+ The "md5" parameter stores the md5 checksum of the license text.
+ If the license text changes in any way as compared to this parameter
+ then a mis-match occurs.
+ This mismatch triggers a build failure and notifies the developer.
+ Notification allows the developer to review and address the license text changes.
+ Also note that if a mis-match occurs during the build, the correct md5
+ checksum is placed in the build log, which can be easily copied to a .bb file.
</para>
<para>
-There is no limit on how many files can be specified on this parameter. But generally every
-project would need specifying of just one or two files for license tracking.
-Many projects would have a "COPYING" file which will store all the
-license information for all the source code files. If the "COPYING" file
-is valid then tracking only that file would be enough.
+ There is no limit to how many files you can specify using the LIC_FILES_CHKSUM variable.
+ Generally, however, every project requires a few specifications for license tracking.
+ Many projects have a "COPYING" file that stores the license information for all the source
+ code files.
+ This practice allow you to just track the "COPYING" file as long as it is kept up to date.
</para>
<tip>
- <para>
-1. If you specify empty or invalid "md5" parameter; then while building
-the package, bitbake will give md5 not matched error, and also show the correct
-"md5" parameter value both on the screen and in the build log
- </para>
- <para>
-2. If the whole file contains only license text, then there is no need to
-specify "beginline" and "endline" parameters.
- </para>
+ If you specify an empty or invalid "md5" parameter, bitback returns an md5 mis-match
+ error and displays the correct "md5" parameter value during the build. The correct parameter
+ is also captured in the build log.
+ </tip>
+ <tip>
+ If the whole file contains only license text, you do not need to use the "beginline" and
+ "endline" parameters.
</tip>
</section>
</section>
- <section id='usingpoky-configuring-DISTRO_PN_ALIAS'>
- <title>Handle package name alias</title>
+
+ <section id="usingpoky-configuring-DISTRO_PN_ALIAS">
+ <title>Handling Package Name Alias</title>
<para>
-Poky implements a distro_check task which automatically connects to major distributions
-and checks whether they contains same package. Sometimes the same package has different
-names in different distributions, which results in a mismatch from distro_check task
-This can be solved by defining per distro recipe name alias -
-<glossterm><link linkend='var-DISTRO_PN_ALIAS'>DISTRO_PN_ALIAS</link></glossterm>
+ Sometimes a package name you are using might exist under an alias or as a similarly named
+ package in a different distribution.
+ Poky implements a distro_check task that automatically connects to major distributions
+ and checks for these situations.
+ If the package exists under a different name in a different distribution you get a
+ distro_check mismatch.
+ You can resolve this problem by defining a per-distro recipe name alias using the
+ <glossterm><link linkend='var-DISTRO_PN_ALIAS'>DISTRO_PN_ALIAS</link></glossterm> variable.
</para>
- <section id='usingpoky-specifying-DISTRO_PN_ALIAS'>
- <title>Specifying the DISTRO_PN_ALIAS variable </title>
-
+ <section id="usingpoky-specifying-DISTRO_PN_ALIAS">
+ <title>Specifying the DISTRO_PN_ALIAS Variable</title>
+ <para>
+ Following is an example that shows how you specify the DISTRO_PN_ALIAS variable:
<programlisting>
DISTRO_PN_ALIAS_pn-PACKAGENAME = "distro1=package_name_alias1 \
distro2=package_name_alias2 \
distro3=package_name_alias3 \
..."
</programlisting>
+ </para>
<para>
-Use space as the delimiter if there're multiple distro aliases
+ If you have more than one distribution alias separate them with a space.
+ Note that Poky currently automatically checks the Fedora, OpenSuSE, Debian, Ubuntu,
+ and Mandriva distributions for source package recipes without having to specify them
+ using the DISTRO_PN_ALIAS variable.
+ For example, the following command generates a report that lists the Linux distributions
+ that include the sources for each of the Poky recipes.
+ <literallayout class='monospaced'>
+ $ bitbake world -f -c distro_check
+ </literallayout>
+ The results are stored in the <filename>build/tmp/log/distro_check-${DATETIME}.results</filename>
+ file.
</para>
- <tip>
- <para>
-The current code can check if the src package for a recipe exists in the latest
-releases of these distributions automatically.
- </para>
- <programlisting>
-Fedora, OpenSuSE, Debian, Ubuntu, Mandriva
- </programlisting>
- <para>
-For example, this command will generate a report, listing which linux distros include the
-sources for each of the poky recipe.
- </para>
- <programlisting>
-bitbake world -f -c distro_check
- </programlisting>
- <para>
-The results will be stored in the build/tmp/log/distro_check-${DATETIME}.results file.
- </para>
- </tip>
</section>
</section>
</chapter>
