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diff --git a/documentation/poky-ref-manual/extendpoky.xml b/documentation/poky-ref-manual/extendpoky.xml index 763670e17c..4fc30534ba 100644 --- a/documentation/poky-ref-manual/extendpoky.xml +++ b/documentation/poky-ref-manual/extendpoky.xml @@ -109,6 +109,7 @@ inherit autotools gettext </para> </section> + <section id='usingpoky-extend-addpkg-makefile'> <title>Makefile-Based Package</title> <para> @@ -160,6 +161,7 @@ do_install () { </programlisting> </section> + <section id='usingpoky-extend-addpkg-files'> <title>Controlling Package Content</title> <para> @@ -348,8 +350,7 @@ RRECOMMENDS_task-custom-tools = "\ </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> @@ -401,107 +402,108 @@ DISTRO_EXTRA_RDEPENDS += "strace" 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 @@ -512,45 +514,44 @@ DISPLAY_ORIENTATION=0 #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" @@ -565,15 +566,14 @@ BBLAYERS = " \ </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}" @@ -586,66 +586,74 @@ BBFILE_PATTERN_emenlow := "^${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 @@ -657,111 +665,121 @@ BBFILE_PRIORITY_emenlow = "6" </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 @@ -770,41 +788,33 @@ src/gz beagleboard http://www.mysite.com/somedir/deploy/ipk/beagleboard</literal </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> @@ -812,184 +822,179 @@ bitbake -c compile -f NAME_OF_PACKAGE </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> |