diff --git a/documentation/poky-ref-manual/extendpoky.xml b/documentation/poky-ref-manual/extendpoky.xml index aedd7c1c68..763670e17c 100644 --- a/documentation/poky-ref-manual/extendpoky.xml +++ b/documentation/poky-ref-manual/extendpoky.xml @@ -4,53 +4,50 @@ Extending Poky - - This section gives information about how to extend the functionality - already present in Poky, documenting standard tasks such as adding new - software packages, extending or customising images or porting poky to - new hardware (adding a new machine). It also contains advice about how - to manage the process of making changes to Poky to achieve best results. + This section provides information about how to extend the functionality + already present in Poky. + The section also documents standard tasks such as adding new + software packages, extending or customizing images or porting Poky to + new hardware (adding a new machine). + Finally, the section contains advice about how + to make changes to Poky to achieve the best results.
Adding a Package - - To add package into Poky you need to write a recipe for it. - Writing a recipe means creating a .bb file which sets various - variables. The variables - useful for recipes are detailed in the - recipe reference section along with more detailed information - about issues such as recipe naming. + To add a package into Poky you need to write a recipe for it. + Writing a recipe means creating a .bb file that sets some + variables. + For information on variables that are useful for recipes and for information about recipe naming + issues, see Recipe Variables - Required + appendix. - Before writing a recipe from scratch it is often useful to check - whether someone else has written one already. OpenEmbedded is a good place - to look as it has a wider scope and hence a wider range of packages. - Poky aims to be compatible with OpenEmbedded so most recipes should + whether someone else has written one already. + OpenEmbedded is a good place to look as it has a wider scope and range of packages. + Because Poky aims to be compatible with OpenEmbedded, most recipes should just work in Poky. - For new packages, the simplest way to add a recipe is to base it on a similar - pre-existing recipe. There are some examples below of how to add - standard types of packages: + pre-existing recipe. + Following are some examples showing how to add standard types of packages:
Single .c File Package (Hello World!) - - To build an application from a single file stored locally (e.g. under "files/") - requires a recipe which has the file listed in the SRC_URI variable. In addition - the do_compile and do_install - tasks need to be manually written. The - S variable defines the directory containing the source - code which in this case is set equal to - WORKDIR, the directory BitBake uses for the build. + Building an application from a single file that is stored locally (e.g. under + files/) requires a recipe that has the file listed in + the SRC_URI variable. + Additionally, you need to manually write the do_compile and + do_install tasks. + The S variable defines the + directory containing the source code, which is set to + WORKDIR in this case - the directory BitBake uses for the build. DESCRIPTION = "Simple helloworld application" @@ -71,32 +68,28 @@ do_install() { install -m 0755 helloworld ${D}${bindir} } - - As a result of the build process "helloworld", "helloworld-dbg" and "hellworld-dev" - packages will be built by default. It is possible to - customise the packaging process. + By default, the "helloworld", "helloworld-dbg" and "hellworld-dev" + packages are built. + For information on how to customize the packaging process, see + Controlling Package Content.
Autotooled Package - - Applications which use autotools (autoconf, automake) - require a recipe which has a source archive listed in - SRC_URI and - inherit autotools to instruct BitBake to use the - autotools.bbclass which has - definitions of all the steps + Applications that use autotools such as autoconf and + automake require a recipe that has a source archive listed in + SRC_URI and + also inherits autotools, which instructs BitBake to use the + autotools.bbclass containing the definitions of all the steps needed to build an autotooled application. - The result of the build will be automatically packaged and if - the application uses NLS to localise then packages with - locale information will be generated (one package per - language). Below is one example (hello_2.2.bb) + The result of the build is automatically packaged. + And, if the application uses NLS for localization, packages with local information are + generated (one package per language). + Following is one example (hello_2.2.bb) - DESCRIPTION = "GNU Helloworld application" SECTION = "examples" @@ -108,50 +101,40 @@ SRC_URI = "${GNU_MIRROR}/hello/hello-${PV}.tar.gz" inherit autotools gettext - - LIC_FILES_CHKSUM - is used to - track source license change. Autotool based recipe can be quickly - created this way like above example. + LIC_FILES_CHKSUM + is used to + track source license change. + You can quickly create autotool-based recipes in a manner similar to the previous example.
-
Makefile-Based Package - - Applications which use GNU make require a recipe which has - the source archive listed in SRC_URI. - Adding a do_compile step - is not needed as by default BitBake will start the "make" - command to compile the application. If there is a need for - additional options to make then they should be stored in the - EXTRA_OEMAKE variable - BitBake - will pass them into the GNU - make invocation. A do_install task is required - - otherwise BitBake will run an empty do_install - task by default. + Applications that use GNU make also require a recipe that has + the source archive listed in SRC_URI. + You do not need to add a do_compile step since by default BitBake + starts the make command to compile the application. + If you need additional make options you should store them in the + EXTRA_OEMAKE variable. + Bitbake passes these options into the make GNU invocation. + Note that a do_install task is still required. + Otherwise BitBake runs an empty do_install task by default. - - Some applications may require extra parameters to be passed to - the compiler, for example an additional header path. This can - be done buy adding to the CFLAGS variable, as in the example below: + Some applications might require extra parameters to be passed to the compiler. + For example the application might need an additional header path. + You can accomplish this by adding to the CFLAGS + variable. + The following example shows this: - CFLAGS_prepend = "-I ${S}/include " - - mtd-utils is an example as Makefile-based: + In the following example mtd-utils is a Makefile-based package: - DESCRIPTION = "Tools for managing memory technology devices." SECTION = "base" @@ -177,25 +160,19 @@ do_install () {
-
- Controlling packages content - + Controlling Package Content - The variables PACKAGES and - FILES are used to split an - application into multiple packages. + You can use the variables PACKAGES and + FILES to split an application into + multiple packages. - - Below the "libXpm" recipe (libxpm_3.5.7.bb) is used as an example. By - default the "libXpm" recipe generates one package - which contains the library - and also a few binaries. The recipe can be adapted to - split the binaries into separate packages. + Following is an example that uses the "libXpm" recipe (libxpm_3.5.7.bb). + By default, the "libXpm" recipe generates a single package containing the library, along + with a few binaries. + You can modify the recipe to split the binaries into separate packages: - require xorg-lib-common.inc @@ -211,20 +188,19 @@ PACKAGES =+ "sxpm cxpm" FILES_cxpm = "${bindir}/cxpm" FILES_sxpm = "${bindir}/sxpm" - - In this example we want to ship the "sxpm" and "cxpm" binaries - in separate packages. Since "bindir" would be packaged into the - main PN - package as standard we prepend the PACKAGES variable so - additional package names are added to the start of list. The - extra FILES_* - variables then contain information to specify which files and - directories goes into which package. Files included by earlier - package are skipped by latter packages, and thus main - PN will not include - above listed files + In the previous example we want to ship the "sxpm" and "cxpm" binaries + in separate packages. + Since "bindir" would be packaged into the main + PN + package by default, we prepend the PACKAGES + variable so additional package names are added to the start of list. + This results in the extra FILES_* + variables then containing information defining which files and + directories go into which package. + Files included by earlier packages are skipped by latter packages. + Thus, the main PN package does not include + the above listed files.
@@ -232,14 +208,13 @@ FILES_sxpm = "${bindir}/sxpm" Post Install Scripts - To add a post-installation script to a package, add - a pkg_postinst_PACKAGENAME() - function to the .bb file - where PACKAGENAME is the name of the package to attach - the postinst script to. Normally PN can be used which expands - to PACKAGENAME automatically. A post-installation function has the - following structure: + To add a post-installation script to a package, add a pkg_postinst_PACKAGENAME() + function to the .bb file and use + PACKAGENAME as the name of the package you want to attach to the + postinst script. + Normally PN can be used, which + automatically expands to PACKAGENAME. + A post-installation function has the following structure: pkg_postinst_PACKAGENAME () { @@ -248,21 +223,18 @@ pkg_postinst_PACKAGENAME () { } - The script defined in the post installation function - gets called when the rootfs is made. If the script succeeds, - the package is marked as installed. If the script fails, - the package is marked as unpacked and the script will be - executed again on the first boot of the image. + The script defined in the post-installation function is called when the rootfs is made. + If the script succeeds, the package is marked as installed. + If the script fails, the package is marked as unpacked and the script is + executed when the image boots again. - - Sometimes it is necessary that the execution of a post-installation - script is delayed until the first boot, because the script - needs to be executed on the device itself. To delay script execution - until boot time, the post-installation function should have the - following structure: + Sometimes it is necessary for the execution of a post-installation + script to be delayed until the first boot. + For example, the script might need to be executed on the device itself. + To delay script execution until boot time, use the following structure for the + post-installation script: - pkg_postinst_PACKAGENAME () { #!/bin/sh -e @@ -273,83 +245,69 @@ else fi } - - The structure above delays execution until first boot - because the D variable points - to the 'image' - directory when the rootfs is being made at build time but + The previous example delays execution until the image boots again because the + D variable points + to the 'image' directory when the rootfs is being made at build time but is unset when executed on the first boot.
-
Customising Images - - Poky images can be customised to satisfy - particular requirements. Several methods are detailed below - along with guidelines of when to use them. + You can customize Poky images to satisfy particular requirements. + This section describes several methods and provides guidelines for each.
- Customising Images through a custom image .bb files - + Customising Images Using Custom .bb Files - One way to get additional software into an image is by creating a - custom image. The recipe will contain two lines: + One way to get additional software into an image is to create a custom image. + The following example shows the form for the two lines you need: - IMAGE_INSTALL = "task-poky-x11-base package1 package2" inherit poky-image - By creating a custom image, a developer has total control - over the contents of the image. It is important to use - the correct names of packages in the IMAGE_INSTALL variable. - The names must be in - the OpenEmbedded notation instead of Debian notation, for example - "glibc-dev" instead of "libc6-dev" etc. + over the contents of the image. + It is important to use the correct names of packages in the + IMAGE_INSTALL variable. + You must use the OpenEmbedded notation and not the Debian notation for the names + (e.g. "glibc-dev" instead of "libc6-dev"). - - The other method of creating a new image is by modifying - an existing image. For example if a developer wants to add - "strace" into "poky-image-sato" the following recipe can - be used: + The other method for creating a custom image is to modify an existing image. + For example, if a developer wants to add "strace" into "poky-image-sato", they can use + the following recipe: - require poky-image-sato.bb IMAGE_INSTALL += "strace" -
- Customising Images through custom tasks - + Customising Images Using Custom Tasks - For complex custom images, the best approach is to create a custom - task package which is then used to build the image (or images). A good - example of a tasks package is meta/packages/tasks/task-poky.bb - . The PACKAGES - variable lists the task packages to build (along with the complementary - -dbg and -dev packages). For each package added, - RDEPENDS and - RRECOMMENDS - entries can then be added each containing a list of packages the parent - task package should contain. An example would be: + For complex custom images, the best approach is to create a custom task package + that is used to build the image or images. + A good example of a tasks package is meta/recipes-sato/tasks/task-poky.bb + . + The PACKAGES + variable lists the task packages to build along with the complementary + -dbg and -dev packages. + For each package added, you can use + RDEPENDS + and RRECOMMENDS + entries to provide a list of packages the parent task package should contain. + Following is an example: - DESCRIPTION = "My Custom Tasks" @@ -378,11 +336,11 @@ RRECOMMENDS_task-custom-tools = "\ kernel-module-oprofile" - - In this example, two task packages are created, task-custom-apps and - task-custom-tools with the dependencies and recommended package dependencies - listed. To build an image using these task packages, you would then add + In the previous example, two task packages are created with their dependencies and their + recommended package dependencies listed: task-custom-apps, and + task-custom-tools. + To build an image using these task packages, you need to add "task-custom-apps" and/or "task-custom-tools" to IMAGE_INSTALL or other forms of image dependencies as described in other areas of this section. @@ -390,131 +348,133 @@ RRECOMMENDS_task-custom-tools = "\
- Customising Images through custom <glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm> - + Customising Images Using Custom <glossterm> + <link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm> - Ultimately users may want to add extra image "features" as used by Poky with the + Ultimately users might want to add extra image "features" as used by Poky with the IMAGE_FEATURES - variable. To create these, the best reference is meta/classes/poky-image.bbclass - which illustrates how poky achieves this. In summary, the file looks at the contents of the + variable. + To create these features, the best reference is + meta/classes/poky-image.bbclass, which shows how poky achieves this. + In summary, the file looks at the contents of the IMAGE_FEATURES - variable and then maps this into a set of tasks or packages. Based on this then the - IMAGE_INSTALL - variable is generated automatically. Extra features can be added by - extending the class or creating a custom class for use with specialised image .bb files. + variable and then maps them into a set of tasks or packages. + Based on this information the IMAGE_INSTALL + variable is generated automatically. + Users can add extra features by extending the class or creating a custom class for use + with specialized image .bb files.
- Customising Images through local.conf - + Customising Images Using local.conf - It is possible to customise image contents by abusing - variables used by distribution maintainers in local.conf. - This method only allows the addition of packages and - is not recommended. + It is possible to customise image contents by abusing variables used by distribution + maintainers in local.conf. + This method only allows the addition of packages and is not recommended. - - To add an "strace" package into the image the following is - added to local.conf: + For example, to add the "strace" package into the image the you would add this to the + local.conf file: - DISTRO_EXTRA_RDEPENDS += "strace" - However, since the DISTRO_EXTRA_RDEPENDS variable is for - distribution maintainers this method does not make - adding packages as simple as a custom .bb file. Using - this method, a few packages will need to be recreated if they have been - created before and then the image is rebuilt. + distribution maintainers, adding packages using this method is not as simple as adding + them using a custom .bb file. + Using the local.conf file method could result in some packages + requiring recreation. + For example, if packages were previously created and the image was rebuilt then the packages + would need to be recreated. + + + Cleaning task-* packages is required because they use the + + DISTRO_EXTRA_RDEPENDS variable. + You do not have to build them by hand because Poky images depend on the packages they contain. + This means dependencies are automatically built when the image builds. + For this reason we don't use the "rebuild" task. + In this case the "rebuild" task does does not care about + dependencies - it only rebuilds the specified package. bitbake -c clean task-boot task-base task-poky bitbake poky-image-sato - - - Cleaning task-* packages is required because they use the - - DISTRO_EXTRA_RDEPENDS variable. There is no need to - build them by hand as Poky images depend on the packages they contain so - dependencies will be built automatically when building the image. For this reason we don't use the - "rebuild" task in this case since "rebuild" does not care about - dependencies - it only rebuilds the specified package. - -
- Porting Poky to a new machine + Porting Poky to a New Machine - Adding a new machine to Poky is a straightforward process and - this section gives an idea of the changes that are needed. This guide is - meant to cover adding machines similar to those Poky already supports. - Adding a totally new architecture might require gcc/glibc changes as - well as updates to the site information and, whilst well within Poky's - capabilities, is outside the scope of this section. + 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 gcc/glibc and to the site information. + Consequently, the information is beyond the scope of this manual.
- Adding the machine configuration file + Adding the Machine Configuration File - A .conf file needs to be added to conf/machine/ with details of the - device being added. The name of the file determines the name Poky will - use to reference this machine. + To add a machine configuration you need to add a .conf file + with details of the device being added to conf/machine/. + The name of the file determines the name Poky uses to reference the new machine. - The most important variables to set in this file are TARGET_ARCH (e.g. "arm"), PREFERRED_PROVIDER_virtual/kernel (see below) and MACHINE_FEATURES - (e.g. "kernel26 apm screen wifi"). Other variables - like SERIAL_CONSOLE + (e.g. "kernel26 apm screen wifi"). + You might also need other variables like SERIAL_CONSOLE (e.g. "115200 ttyS0"), KERNEL_IMAGETYPE (e.g. "zImage") and - IMAGE_FSTYPES (e.g. "tar.gz jffs2") might also be - needed. Full details on what these variables do and the meaning of - their contents is available through the links. There're lots of existing - machine .conf files which can be easily leveraged from meta/conf/machine/. + IMAGE_FSTYPES (e.g. "tar.gz jffs2"). + You can find full details on these variables in the reference section. + You can leverage many existing machine .conf files from + meta/conf/machine/.
- Adding a kernel for the machine + Adding a Kernel for the Machine - 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. There are plenty of kernel examples in the - meta/recipes-kernel/linux directory which can be used as references. + 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 meta/recipes-kernel/linux + directory that can be used as references. - If creating a new recipe the "normal" recipe writing rules apply - for setting up a SRC_URI - including any patches and setting - S to point at the source - code. You will need to create a configure task which configures the - unpacked kernel with a defconfig be that through a "make defconfig" - command or more usually though copying in a suitable defconfig and - running "make oldconfig". By making use of "inherit kernel" and also - maybe some of the linux-*.inc files, most other functionality is - centralised and the the defaults of the class normally work well. + If you are creating a new recipe, the "normal" recipe-writing rules apply for setting + up a SRC_URI. + This means specifying any necessary patches and setting + S 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 make defconfig command or + more commonly by copying in a suitable defconfig and and then running + make oldconfig. + By making use of "inherit kernel" and potentially some of the + linux-*.inc files, most other functionality is + centralized and the the defaults of the class normally work well. - If extending an existing kernel it is usually a case of adding a - suitable defconfig file in a location similar to that used by other - machine's defconfig files in a given kernel, possibly listing it in - the SRC_URI and adding the machine to the expression in - COMPATIBLE_MACHINE - : + If you are extending an existing kernel, it is usually a matter of adding a + suitable defconfig file. + The file needs to be added into a location similar to defconfig files + used for other machines in a given kernel. + A possible way to do this is by listing the file in the + SRC_URI + and adding the machine to the expression in + COMPATIBLE_MACHINE: COMPATIBLE_MACHINE = '(qemux86|qemumips)' @@ -522,7 +482,7 @@ COMPATIBLE_MACHINE = '(qemux86|qemumips)'
- Adding a formfactor configuration file + Adding a Formfactor Configuration File A formfactor configuration file provides information about the target hardware on which Poky is running, and that Poky cannot diff --git a/documentation/poky-ref-manual/usingpoky.xml b/documentation/poky-ref-manual/usingpoky.xml index c2e102ce37..4f75e1a279 100644 --- a/documentation/poky-ref-manual/usingpoky.xml +++ b/documentation/poky-ref-manual/usingpoky.xml @@ -205,7 +205,7 @@ $ bitbake <target>
- Running specific tasks + Running Specific Tasks Any given package consists of a set of tasks. In most cases the series is: fetch, unpack, patch, configure, @@ -287,24 +287,20 @@ $ bitbake matchbox-desktop -c
- Building with no dependencies - + Building with No Dependencies - If you really want to build a specific .bb file, you can use - the form bitbake -b somepath/somefile.bb. Note that this - will not check the dependencies so this option should only - be used when you know its dependencies already exist. You - can specify fragments of the filename and bitbake will see - if it can find a unique match. + If you really want to build a specific .bb file, you can use + the command form bitbake -b somepath/somefile.bb. + This command form does not check for dependencies so you should use it + only when you know its dependencies already exist. + You can also specify fragments of the filename and bitbake checks for a unique match. -
Variables - - The "-e" option will dump the resulting environment for + The "-e" option dumps the resulting environment for either the configuration (no package specified) or for a specific package when specified with the "-b" option. @@ -312,23 +308,23 @@ $ bitbake matchbox-desktop -c
Other Tips - - When adding new packages it is worth keeping an eye open for bad - things creeping into compiler commandlines such as references to local - system files (/usr/lib/ or /usr/include/ etc.). + + When adding new packages it is worth watching for undesireable items making their way + into compiler command lines. + For example, you do not want references to local system files like + /usr/lib/ or /usr/include/. - If you want to remove the psplash boot splashscreen, add "psplash=false" - to the kernel commandline and psplash won't load allowing you to see - the console. It's also possible to switch out of the splashscreen by - switching virtual console (Fn+Left or Fn+Right on a Zaurus). + to the kernel command line. + Doing so prevents psplash from loading thus allowing you to see the console. + It is also possible to switch out of the splashscreen by + switching the virtual console (e.g. Fn+Left or Fn+Right on a Zaurus). -