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General edits to the using poky and Extending Poky chapters. 

I completed general edits to the second chapter of the poky reference
manual.  These edits went from section 2.4.5 through the end of the
chapter.  They consist of text rewrites for more active voice and follow
general technical writing principles.

I completed the same types of edits in the third chapter of the manual
from the beginning through section 3.3.2.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
This commit is contained in:
Scott Rifenbark 2010-10-28 14:29:17 -07:00 committed by Richard Purdie
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documentation/poky-ref-manual/extendpoky.xml
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@ -4,53 +4,50 @@
<chapter id='extendpoky'>
<title>Extending Poky</title>
<para>
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.
</para>
<section id='usingpoky-extend-addpkg'>
<title>Adding a Package</title>
<para>
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 <link linkend='ref-varlocality-recipe-required'>
recipe reference</link> 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 <filename>.bb</filename> file that sets some
variables.
For information on variables that are useful for recipes and for information about recipe naming
issues, see <link linkend='ref-varlocality-recipe-required'>Recipe Variables - Required</link>
appendix.
</para>
<para>
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.
</para>
<para>
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:
</para>
<section id='usingpoky-extend-addpkg-singlec'>
<title>Single .c File Package (Hello World!)</title>
<para>
To build an application from a single file stored locally (e.g. under "files/")
requires a recipe which has the file listed in the <glossterm><link
linkend='var-SRC_URI'>SRC_URI</link></glossterm> variable. In addition
the <function>do_compile</function> and <function>do_install</function>
tasks need to be manually written. The <glossterm><link linkend='var-S'>
S</link></glossterm> variable defines the directory containing the source
code which in this case is set equal to <glossterm><link linkend='var-WORKDIR'>
WORKDIR</link></glossterm>, the directory BitBake uses for the build.
Building an application from a single file that is stored locally (e.g. under
<filename>files/</filename>) requires a recipe that has the file listed in
the <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm> variable.
Additionally, you need to manually write the <function>do_compile</function> and
<function>do_install</function> tasks.
The <glossterm><link linkend='var-S'>S</link></glossterm> variable defines the
directory containing the source code, which is set to <glossterm><link linkend='var-WORKDIR'>
WORKDIR</link></glossterm> in this case - the directory BitBake uses for the build.
</para>
<programlisting>
DESCRIPTION = "Simple helloworld application"
@ -71,32 +68,28 @@ do_install() {
install -m 0755 helloworld ${D}${bindir}
}
</programlisting>
<para>
As a result of the build process "helloworld", "helloworld-dbg" and "hellworld-dev"
packages will be built by default. It is possible to<link linkend='usingpoky-extend-addpkg-files'>
customise the packaging process</link>.
By default, the "helloworld", "helloworld-dbg" and "hellworld-dev"
packages are built.
For information on how to customize the packaging process, see
<link linkend='usingpoky-extend-addpkg-files'>Controlling Package Content</link>.
</para>
</section>
<section id='usingpoky-extend-addpkg-autotools'>
<title>Autotooled Package</title>
<para>
Applications which use autotools (autoconf, automake)
require a recipe which has a source archive listed in
<glossterm><link
linkend='var-SRC_URI'>SRC_URI</link></glossterm> and
<command>inherit autotools</command> to instruct BitBake to use the
<filename>autotools.bbclass</filename> which has
definitions of all the steps
Applications that use autotools such as <filename>autoconf</filename> and
<filename>automake</filename> require a recipe that has a source archive listed in
<glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm> and
<filename>also inherits autotools</filename>, which instructs BitBake to use the
<filename>autotools.bbclass</filename> 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 (<filename>hello_2.2.bb</filename>)
</para>
<programlisting>
DESCRIPTION = "GNU Helloworld application"
SECTION = "examples"
@ -108,50 +101,40 @@ SRC_URI = "${GNU_MIRROR}/hello/hello-${PV}.tar.gz"
inherit autotools gettext
</programlisting>
<para>
<glossterm><link linkend='var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</link>
</glossterm> is used to <link linkend='usingpoky-configuring-LIC_FILES_CHKSUM'>
track source license change</link>. Autotool based recipe can be quickly
created this way like above example.
<glossterm><link linkend='var-LIC_FILES_CHKSUM'>LIC_FILES_CHKSUM</link>
</glossterm> is used to <link linkend='usingpoky-configuring-LIC_FILES_CHKSUM'>
track source license change</link>.
You can quickly create autotool-based recipes in a manner similar to the previous example.
</para>
</section>
<section id='usingpoky-extend-addpkg-makefile'>
<title>Makefile-Based Package</title>
<para>
Applications which use GNU make require a recipe which has
the source archive listed in <glossterm><link
linkend='var-SRC_URI'>SRC_URI</link></glossterm>.
Adding a <function>do_compile</function> 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
<glossterm><link
linkend='var-EXTRA_OEMAKE'>EXTRA_OEMAKE</link></glossterm> variable - BitBake
will pass them into the GNU
make invocation. A <function>do_install</function> task is required
- otherwise BitBake will run an empty <function>do_install</function>
task by default.
Applications that use GNU <filename>make</filename> also require a recipe that has
the source archive listed in <glossterm><link linkend='var-SRC_URI'>SRC_URI</link></glossterm>.
You do not need to add a <function>do_compile</function> step since by default BitBake
starts the <filename>make</filename> command to compile the application.
If you need additional <filename>make</filename> options you should store them in the
<glossterm><link linkend='var-EXTRA_OEMAKE'>EXTRA_OEMAKE</link></glossterm> variable.
Bitbake passes these options into the <filename>make</filename> GNU invocation.
Note that a <function>do_install</function> task is still required.
Otherwise BitBake runs an empty <function>do_install</function> task by default.
</para>
<para>
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 <glossterm><link
linkend='var-CFLAGS'>CFLAGS</link></glossterm> 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 <glossterm><link linkend='var-CFLAGS'>CFLAGS</link>
</glossterm> variable.
The following example shows this:
</para>
<programlisting>
CFLAGS_prepend = "-I ${S}/include "
</programlisting>
<para>
mtd-utils is an example as Makefile-based:
In the following example <filename>mtd-utils</filename> is a Makefile-based package:
</para>
<programlisting>
DESCRIPTION = "Tools for managing memory technology devices."
SECTION = "base"
@ -177,25 +160,19 @@ do_install () {
</programlisting>
</section>
<section id='usingpoky-extend-addpkg-files'>
<title>Controlling packages content</title>
<title>Controlling Package Content</title>
<para>
The variables <glossterm><link
linkend='var-PACKAGES'>PACKAGES</link></glossterm> and
<glossterm><link linkend='var-FILES'>FILES</link></glossterm> are used to split an
application into multiple packages.
You can use the variables <glossterm><link linkend='var-PACKAGES'>PACKAGES</link></glossterm> and
<glossterm><link linkend='var-FILES'>FILES</link></glossterm> to split an application into
multiple packages.
</para>
<para>
Below the "libXpm" recipe (libxpm_3.5.7.bb) is used as an example. By
default the "libXpm" recipe generates one package
which contains the library
and also a few binaries. The recipe can be adapted to
split the binaries into separate packages.
Following is an example that uses the "libXpm" recipe (<filename>libxpm_3.5.7.bb</filename>).
By default, the "libXpm" recipe generates a single package containing the library, along
with a few binaries.
You can modify the recipe to split the binaries into separate packages:
</para>
<programlisting>
require xorg-lib-common.inc
@ -211,20 +188,19 @@ PACKAGES =+ "sxpm cxpm"
FILES_cxpm = "${bindir}/cxpm"
FILES_sxpm = "${bindir}/sxpm"
</programlisting>
<para>
In this example we want to ship the "sxpm" and "cxpm" binaries
in separate packages. Since "bindir" would be packaged into the
main <glossterm><link linkend='var-PN'>PN</link></glossterm>
package as standard we prepend the <glossterm><link
linkend='var-PACKAGES'>PACKAGES</link></glossterm> variable so
additional package names are added to the start of list. The
extra <glossterm><link linkend='var-FILES'>FILES</link></glossterm>_*
variables then contain information to specify which files and
directories goes into which package. Files included by earlier
package are skipped by latter packages, and thus main <glossterm>
<link linkend='var-PN'>PN</link></glossterm> will not include
above listed files
In the previous example we want to ship the "sxpm" and "cxpm" binaries
in separate packages.
Since "bindir" would be packaged into the main
<glossterm><link linkend='var-PN'>PN</link></glossterm>
package by default, we prepend the <glossterm><link linkend='var-PACKAGES'>PACKAGES</link>
</glossterm> variable so additional package names are added to the start of list.
This results in the extra <glossterm><link linkend='var-FILES'>FILES</link></glossterm>_*
variables then containing information defining which files and
directories go into which package.
Files included by earlier packages are skipped by latter packages.
Thus, the main <glossterm><link linkend='var-PN'>PN</link></glossterm> package does not include
the above listed files.
</para>
</section>
@ -232,14 +208,13 @@ FILES_sxpm = "${bindir}/sxpm"
<title>Post Install Scripts</title>
<para>
To add a post-installation script to a package, add
a <function>pkg_postinst_PACKAGENAME()</function>
function to the .bb file
where PACKAGENAME is the name of the package to attach
the postinst script to. Normally <glossterm><link
linkend='var-PN'>PN</link></glossterm> 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 <function>pkg_postinst_PACKAGENAME()
</function> function to the <filename>.bb</filename> file and use
<filename>PACKAGENAME</filename> as the name of the package you want to attach to the
<filename>postinst</filename> script.
Normally <glossterm><link linkend='var-PN'>PN</link></glossterm> can be used, which
automatically expands to PACKAGENAME.
A post-installation function has the following structure:
</para>
<programlisting>
pkg_postinst_PACKAGENAME () {
@ -248,21 +223,18 @@ pkg_postinst_PACKAGENAME () {
}
</programlisting>
<para>
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.
</para>
<para>
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:
</para>
<programlisting>
pkg_postinst_PACKAGENAME () {
#!/bin/sh -e
@ -273,83 +245,69 @@ else
fi
}
</programlisting>
<para>
The structure above delays execution until first boot
because the <glossterm><link
linkend='var-D'>D</link></glossterm> 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
<glossterm><link linkend='var-D'>D</link></glossterm> variable points
to the 'image' directory when the rootfs is being made at build time but
is unset when executed on the first boot.
</para>
</section>
</section>
<section id='usingpoky-extend-customimage'>
<title>Customising Images</title>
<para>
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.
</para>
<section id='usingpoky-extend-customimage-custombb'>
<title>Customising Images through a custom image .bb files</title>
<title>Customising Images Using Custom .bb Files</title>
<para>
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:
</para>
<programlisting>
IMAGE_INSTALL = "task-poky-x11-base package1 package2"
inherit poky-image
</programlisting>
<para>
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 <glossterm><link
linkend='var-IMAGE_INSTALL'>IMAGE_INSTALL</link></glossterm> 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
<glossterm><link linkend='var-IMAGE_INSTALL'>IMAGE_INSTALL</link></glossterm> variable.
You must use the OpenEmbedded notation and not the Debian notation for the names
(e.g. "glibc-dev" instead of "libc6-dev").
</para>
<para>
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:
</para>
<programlisting>
require poky-image-sato.bb
IMAGE_INSTALL += "strace"
</programlisting>
</section>
<section id='usingpoky-extend-customimage-customtasks'>
<title>Customising Images through custom tasks</title>
<title>Customising Images Using Custom Tasks</title>
<para>
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 <filename>meta/packages/tasks/task-poky.bb
</filename>. The <glossterm><link linkend='var-PACKAGES'>PACKAGES</link></glossterm>
variable lists the task packages to build (along with the complementary
-dbg and -dev packages). For each package added,
<glossterm><link linkend='var-PACKAGES'>RDEPENDS</link></glossterm> and
<glossterm><link linkend='var-PACKAGES'>RRECOMMENDS</link></glossterm>
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 <filename>meta/recipes-sato/tasks/task-poky.bb
</filename>.
The <glossterm><link linkend='var-PACKAGES'>PACKAGES</link></glossterm>
variable lists the task packages to build along with the complementary
-dbg and -dev packages.
For each package added, you can use
<glossterm><link linkend='var-PACKAGES'>RDEPENDS</link></glossterm>
and <glossterm><link linkend='var-PACKAGES'>RRECOMMENDS</link></glossterm>
entries to provide a list of packages the parent task package should contain.
Following is an example:
</para>
<para>
<programlisting>
DESCRIPTION = "My Custom Tasks"
@ -378,11 +336,11 @@ RRECOMMENDS_task-custom-tools = "\
kernel-module-oprofile"
</programlisting>
</para>
<para>
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: <filename>task-custom-apps</filename>, and
<filename>task-custom-tools</filename>.
To build an image using these task packages, you need to add
"task-custom-apps" and/or "task-custom-tools" to <glossterm><link
linkend='var-IMAGE_INSTALL'>IMAGE_INSTALL</link></glossterm> or other forms
of image dependencies as described in other areas of this section.
@ -390,131 +348,133 @@ RRECOMMENDS_task-custom-tools = "\
</section>
<section id='usingpoky-extend-customimage-imagefeatures'>
<title>Customising Images through custom <glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm></title>
<title>Customising Images Using Custom <glossterm>
<link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm></title>
<para>
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
<glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm>
variable. To create these, the best reference is <filename>meta/classes/poky-image.bbclass</filename>
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
<filename>meta/classes/poky-image.bbclass</filename>, which shows how poky achieves this.
In summary, the file looks at the contents of the
<glossterm><link linkend='var-IMAGE_FEATURES'>IMAGE_FEATURES</link></glossterm>
variable and then maps this into a set of tasks or packages. Based on this then the
<glossterm><link linkend='var-IMAGE_INSTALL'> IMAGE_INSTALL</link></glossterm>
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 <glossterm><link linkend='var-IMAGE_INSTALL'> IMAGE_INSTALL</link>
</glossterm> variable is generated automatically.
Users can add extra features by extending the class or creating a custom class for use
with specialized image <filename>.bb</filename> files.
</para>
</section>
<section id='usingpoky-extend-customimage-localconf'>
<title>Customising Images through local.conf</title>
<title>Customising Images Using local.conf</title>
<para>
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.
</para>
<para>
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
<filename>local.conf</filename> file:
</para>
<programlisting>
DISTRO_EXTRA_RDEPENDS += "strace"
</programlisting>
<para>
However, since the <glossterm><link linkend='var-DISTRO_EXTRA_RDEPENDS'>
DISTRO_EXTRA_RDEPENDS</link></glossterm> 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 <filename>.bb</filename> file.
Using the <filename>local.conf</filename> 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.
</para>
<para>
Cleaning task-* packages is required because they use the
<glossterm><link linkend='var-DISTRO_EXTRA_RDEPENDS'>
DISTRO_EXTRA_RDEPENDS</link></glossterm> 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.
</para>
<programlisting>
bitbake -c clean task-boot task-base task-poky
bitbake poky-image-sato
</programlisting>
<para>
Cleaning task-* packages is required because they use the
<glossterm><link linkend='var-DISTRO_EXTRA_RDEPENDS'>
DISTRO_EXTRA_RDEPENDS</link></glossterm> 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.
</para>
</section>
</section>
<section id="platdev-newmachine">
<title>Porting Poky to a new machine</title>
<title>Porting Poky to a New Machine</title>
<para>
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 <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>
<title>Adding the Machine Configuration File</title>
<para>
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 <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"). Other variables
like <glossterm><link linkend='var-SERIAL_CONSOLE'>SERIAL_CONSOLE
</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") 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</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>
<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. 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 <filename>meta/recipes-kernel/linux</filename>
directory that can be used as references.
</para>
<para>
If creating a new recipe the "normal" recipe writing rules apply
for setting up a <glossterm><link linkend='var-SRC_URI'>SRC_URI
</link></glossterm> including any patches and setting <glossterm>
<link linkend='var-S'>S</link></glossterm> 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 <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 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 <glossterm>
<link linkend='var-COMPATIBLE_MACHINE'>COMPATIBLE_MACHINE</link>
</glossterm>:
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)'
@ -522,7 +482,7 @@ COMPATIBLE_MACHINE = '(qemux86|qemumips)'
</section>
<section id="platdev-newmachine-formfactor">
<title>Adding a formfactor configuration file</title>
<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

38
documentation/poky-ref-manual/usingpoky.xml
View File

@ -205,7 +205,7 @@ $ bitbake &lt;target&gt;
</section>
<section id='usingpoky-debugging-taskrunning'>
<title>Running specific tasks</title>
<title>Running Specific Tasks</title>
<para> 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
</section>
<section id='usingpoky-debugging-buildfile'>
<title>Building with no dependencies</title>
<title>Building with No Dependencies</title>
<para>
If you really want to build a specific .bb file, you can use
the form <command>bitbake -b somepath/somefile.bb</command>. 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 <filename>.bb</filename> file, you can use
the command form <filename>bitbake -b somepath/somefile.bb</filename>.
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.
</para>
</section>
<section id='usingpoky-debugging-variables'>
<title>Variables</title>
<para>
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.
</para>
@ -312,23 +308,23 @@ $ bitbake matchbox-desktop -c
<section id='usingpoky-debugging-others'>
<title>Other Tips</title>
<tip>
<para>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 (<filename>/usr/lib/</filename> or <filename>/usr/include/</filename> etc.).
<para>
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
<filename>/usr/lib/</filename> or <filename>/usr/include/</filename>.
</para>
</tip>
<tip>
<para>
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).
</para>
</tip>
</section>
</section>