2010-11-04 20:01:19 +00:00
|
|
|
<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
2012-03-08 21:17:14 +00:00
|
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
|
|
|
|
[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] >
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<chapter id='bsp'>
|
|
|
|
|
2011-08-18 23:00:16 +00:00
|
|
|
<title>Board Support Packages (BSP) - Developer's Guide</title>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
|
|
|
A Board Support Package (BSP) is a collection of information that
|
|
|
|
defines how to support a particular hardware device, set of devices, or
|
|
|
|
hardware platform.
|
|
|
|
The BSP includes information about the hardware features
|
|
|
|
present on the device and kernel configuration information along with any
|
|
|
|
additional hardware drivers required.
|
|
|
|
The BSP also lists any additional software
|
|
|
|
components required in addition to a generic Linux software stack for both
|
|
|
|
essential and optional platform features.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2012-03-08 21:17:14 +00:00
|
|
|
This chapter (or document if you are reading the BSP Developer's Guide) defines
|
2010-11-11 18:59:49 +00:00
|
|
|
a structure for these components
|
2010-11-04 20:01:19 +00:00
|
|
|
so that BSPs follow a commonly understood layout.
|
|
|
|
Providing a common form allows end-users to understand and become familiar
|
|
|
|
with the layout.
|
|
|
|
A common form also encourages standardization
|
|
|
|
of software support of hardware.
|
|
|
|
</para>
|
|
|
|
|
2011-08-18 23:00:16 +00:00
|
|
|
<note>
|
2011-07-14 22:33:13 +00:00
|
|
|
The information here does not provide an example of how to create a BSP.
|
2011-08-29 18:46:27 +00:00
|
|
|
For examples on how to create a BSP, see the
|
2012-03-08 21:17:14 +00:00
|
|
|
"<ulink url='&YOCTO_DOCS_DEV_URL;#dev-manual-bsp-appendix'>BSP Development Example</ulink>"
|
2012-02-06 21:29:08 +00:00
|
|
|
section in The Yocto Project Development Manual.
|
2011-08-29 18:46:27 +00:00
|
|
|
You can also see the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_WIKI_URL;/wiki/Transcript:_creating_one_generic_Atom_BSP_from_another'>
|
2011-08-29 18:46:27 +00:00
|
|
|
wiki page</ulink>.
|
2011-08-18 23:00:16 +00:00
|
|
|
</note>
|
2011-07-14 22:33:13 +00:00
|
|
|
|
2010-11-04 20:01:19 +00:00
|
|
|
<para>
|
2011-07-14 21:49:34 +00:00
|
|
|
The proposed format does have elements that are specific to the Yocto Project and
|
2010-11-04 20:01:19 +00:00
|
|
|
OpenEmbedded build systems.
|
|
|
|
It is intended that this information can be
|
2011-07-14 21:49:34 +00:00
|
|
|
used by other systems besides Yocto Project and OpenEmbedded and that it will be simple
|
2010-11-04 20:01:19 +00:00
|
|
|
to extract information and convert it to other formats if required.
|
2011-07-14 21:49:34 +00:00
|
|
|
Yocto Project, through its standard layers mechanism, can directly accept the format
|
2010-11-04 20:01:19 +00:00
|
|
|
described as a layer.
|
|
|
|
The BSP captures all
|
2010-11-11 18:23:10 +00:00
|
|
|
the hardware-specific details in one place in a standard format, which is
|
2010-11-04 20:01:19 +00:00
|
|
|
useful for any person wishing to use the hardware platform regardless of
|
2010-11-11 18:23:10 +00:00
|
|
|
the build system they are using.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
The BSP specification does not include a build system or other tools -
|
|
|
|
it is concerned with the hardware-specific components only.
|
2012-02-22 20:43:04 +00:00
|
|
|
At the end-distribution point, you can ship the BSP combined with a build system
|
2010-11-04 20:01:19 +00:00
|
|
|
and other tools.
|
|
|
|
However, it is important to maintain the distinction that these
|
|
|
|
are separate components that happen to be combined in certain end products.
|
|
|
|
</para>
|
|
|
|
|
2012-02-17 21:03:46 +00:00
|
|
|
<section id='bsp-layers'>
|
|
|
|
<title>BSP Layers</title>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
2012-02-17 21:03:46 +00:00
|
|
|
The BSP consists of a file structure inside a base directory.
|
|
|
|
Collectively, you can think of the base directory and the file structure
|
|
|
|
as a BSP Layer.
|
|
|
|
BSP Layers use the following naming convention:
|
2010-12-14 00:21:12 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>
|
|
|
|
</literallayout>
|
2012-02-17 21:03:46 +00:00
|
|
|
"bsp_name" is a placeholder for the machine or platform name.
|
2011-05-17 19:03:04 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2012-02-17 21:03:46 +00:00
|
|
|
The Yocto Project organizes BSP Layers within the Yocto Metadata Layers area
|
|
|
|
of the Yocto Project Source Repositories at
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink>.
|
2012-02-17 21:03:46 +00:00
|
|
|
If you examine the source repositories, you will find many BSP Layers.
|
|
|
|
Here are a few:
|
2010-12-14 00:21:12 +00:00
|
|
|
<literallayout class='monospaced'>
|
2012-02-17 21:03:46 +00:00
|
|
|
meta-baryon
|
|
|
|
meta-fsl-ppc
|
|
|
|
meta-intel
|
|
|
|
meta-selinux
|
|
|
|
meta-ti
|
|
|
|
</literallayout>
|
|
|
|
It is worth noting that the <filename>meta-intel</filename> BSP Layer contains
|
2012-02-22 20:43:04 +00:00
|
|
|
within itself several other BSP Layers, which makes it sort of a "super" BSP layer.
|
2012-02-17 21:03:46 +00:00
|
|
|
Following is a sampling of the BSP Layers that the <filename>meta-intel</filename>
|
|
|
|
BSP Layer contains:
|
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-cedartrail
|
|
|
|
meta-crownbay
|
2010-12-15 01:08:07 +00:00
|
|
|
meta-emenlow
|
2012-02-17 21:03:46 +00:00
|
|
|
meta-fishriver
|
|
|
|
meta-fri2
|
2010-12-14 00:21:12 +00:00
|
|
|
</literallayout>
|
|
|
|
</para>
|
|
|
|
|
2011-05-17 19:03:04 +00:00
|
|
|
<para>
|
2012-02-17 21:03:46 +00:00
|
|
|
The layer's base directory (<filename>meta-<bsp_name></filename>) is the root
|
|
|
|
of the BSP Layer.
|
2011-08-18 23:00:16 +00:00
|
|
|
This root is what you add to the <filename>BBLAYERS</filename>
|
2012-02-22 20:43:04 +00:00
|
|
|
variable in the <filename>conf/bblayers.conf</filename> file found in the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-build-directory'>Yocto Project Build Directory</ulink>.
|
2011-08-18 23:00:16 +00:00
|
|
|
Adding the root allows the Yocto Project build system to recognize the BSP
|
|
|
|
definition and from it build an image.
|
2011-05-17 19:03:04 +00:00
|
|
|
Here is an example:
|
|
|
|
<literallayout class='monospaced'>
|
|
|
|
BBLAYERS = " \
|
|
|
|
/usr/local/src/yocto/meta \
|
|
|
|
/usr/local/src/yocto/meta-yocto \
|
|
|
|
/usr/local/src/yocto/meta-<bsp_name> \
|
|
|
|
"
|
|
|
|
</literallayout>
|
2012-02-17 21:03:46 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2011-05-17 19:03:04 +00:00
|
|
|
For more detailed information on layers, see the
|
2012-03-08 21:17:14 +00:00
|
|
|
"<ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>Understanding and Creating Layers</ulink>"
|
2012-02-17 21:03:46 +00:00
|
|
|
section of the Yocto Project Development Manual.
|
2011-08-18 23:00:16 +00:00
|
|
|
You can also see the detailed examples in the appendices of
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;'>The Yocto Project Development Manual</ulink>.
|
2011-05-17 19:03:04 +00:00
|
|
|
</para>
|
2012-02-17 21:03:46 +00:00
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
|
|
<section id="bsp-filelayout">
|
|
|
|
<title>Example Filesystem Layout</title>
|
2011-05-17 19:03:04 +00:00
|
|
|
|
2010-12-14 00:21:12 +00:00
|
|
|
<para>
|
2012-02-17 21:03:46 +00:00
|
|
|
Below is the common form for the file structure inside a BSP Layer.
|
2010-12-15 17:28:22 +00:00
|
|
|
While you can use this basic form for the standard, realize that the actual structures
|
|
|
|
for specific BSPs could differ.
|
|
|
|
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/
|
|
|
|
meta-<bsp_name>/<bsp_license_file>
|
|
|
|
meta-<bsp_name>/README
|
|
|
|
meta-<bsp_name>/binary/<bootable_images>
|
|
|
|
meta-<bsp_name>/conf/layer.conf
|
|
|
|
meta-<bsp_name>/conf/machine/*.conf
|
|
|
|
meta-<bsp_name>/recipes-bsp/*
|
|
|
|
meta-<bsp_name>/recipes-graphics/*
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-<bsp_name>/recipes-kernel/linux/linux-yocto_<kernel_rev>.bbappend
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
Below is an example of the Crown Bay BSP:
|
2011-08-18 23:00:16 +00:00
|
|
|
|
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-crownbay/COPYING.MIT
|
|
|
|
meta-crownbay/README
|
2012-02-22 20:43:04 +00:00
|
|
|
meta-crownbay/README.sources
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/binary
|
|
|
|
meta-crownbay/conf/
|
2011-08-18 23:00:16 +00:00
|
|
|
meta-crownbay/conf/layer.conf
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/conf/machine/
|
2011-08-18 23:00:16 +00:00
|
|
|
meta-crownbay/conf/machine/crownbay.conf
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/conf/machine/crownbay-noemgd.conf
|
|
|
|
meta-crownbay/recipes-bsp/
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/
|
2011-08-18 23:00:16 +00:00
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor_0.0.bbappend
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay/
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay/machconfig
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay-noemgd/
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay-noemgd/machconfig
|
2011-09-28 19:36:33 +00:00
|
|
|
meta-crownbay/recipes-core
|
|
|
|
meta-crownbay/recipes-core/tasks
|
2012-02-22 20:43:04 +00:00
|
|
|
meta-crownbay/recipes-core/tasks/task-core-tools-profile.bbappend
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-graphics/
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/
|
2011-08-18 23:00:16 +00:00
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay/
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay/xorg.conf
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay-noemgd/
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay-noemgd/xorg.conf
|
|
|
|
meta-crownbay/recipes-kernel/
|
|
|
|
meta-crownbay/recipes-kernel/linux/
|
2012-02-22 20:43:04 +00:00
|
|
|
meta-crownbay/recipes-kernel/linux/linux-yocto-rt_3.0.bbappend
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-kernel/linux/linux-yocto_2.6.37.bbappend
|
|
|
|
meta-crownbay/recipes-kernel/linux/linux-yocto_3.0.bbappend
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-12-15 20:46:11 +00:00
|
|
|
</para>
|
|
|
|
|
2010-11-04 20:01:19 +00:00
|
|
|
<para>
|
2010-12-15 20:56:20 +00:00
|
|
|
The following sections describe each part of the proposed BSP format.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id="bsp-filelayout-license">
|
2010-12-15 21:11:27 +00:00
|
|
|
<title>License Files</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
|
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/<bsp_license_file>
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-12-15 21:11:27 +00:00
|
|
|
|
|
|
|
<para>
|
|
|
|
These optional files satisfy licensing requirements for the BSP.
|
|
|
|
The type or types of files here can vary depending on the licensing requirements.
|
2011-08-29 18:46:27 +00:00
|
|
|
For example, in the Crown Bay BSP all licensing requirements are handled with the
|
2010-12-15 21:11:27 +00:00
|
|
|
<filename>COPYING.MIT</filename> file.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Licensing files can be MIT, BSD, GPLv*, and so forth.
|
|
|
|
These files are recommended for the BSP but are optional and totally up to the BSP developer.
|
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-12-15 21:19:09 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id="bsp-filelayout-readme">
|
2010-12-15 21:19:09 +00:00
|
|
|
<title>README File</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:54:58 +00:00
|
|
|
You can find this file in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/README
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-12-15 21:19:09 +00:00
|
|
|
|
|
|
|
<para>
|
|
|
|
This file provides information on how to boot the live images that are optionally
|
|
|
|
included in the <filename>/binary</filename> directory.
|
|
|
|
The <filename>README</filename> file also provides special information needed for
|
|
|
|
building the image.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2012-02-22 20:54:58 +00:00
|
|
|
Technically speaking a <filename>README</filename> file is optional but it is highly
|
|
|
|
recommended that every BSP has one.
|
|
|
|
</para>
|
|
|
|
</section>
|
|
|
|
|
|
|
|
<section id="bsp-filelayout-readme-sources">
|
|
|
|
<title>README.sources File</title>
|
|
|
|
<para>
|
|
|
|
You can find this file in the BSP Layer at:
|
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/README.sources
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
This file provides information on where to locate the BSP source files.
|
|
|
|
For example, information provides where to find the sources that comprise
|
|
|
|
the images shipped with the BSP.
|
|
|
|
Information is also included to help you find the metadata used to generate the images
|
|
|
|
that ship with the BSP.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
Technically speaking a <filename>README.sources</filename> file is optional but it is highly
|
2010-12-15 21:19:09 +00:00
|
|
|
recommended that every BSP has one.
|
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-12-15 21:11:27 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id="bsp-filelayout-binary">
|
2010-12-15 21:26:13 +00:00
|
|
|
<title>Pre-built User Binaries</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/binary/<bootable_images>
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
2011-03-17 19:35:27 +00:00
|
|
|
This optional area contains useful pre-built kernels and user-space filesystem
|
2010-12-15 01:03:53 +00:00
|
|
|
images appropriate to the target system.
|
2011-05-17 16:28:25 +00:00
|
|
|
This directory typically contains graphical (e.g. sato) and minimal live images
|
2012-02-22 20:58:23 +00:00
|
|
|
when the BSP tarball has been created and made available in the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_HOME_URL;'>Yocto Project</ulink> website.
|
2010-12-14 00:21:12 +00:00
|
|
|
You can use these kernels and images to get a system running and quickly get started
|
2010-12-15 21:26:13 +00:00
|
|
|
on development tasks.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2010-12-14 00:21:12 +00:00
|
|
|
The exact types of binaries present are highly hardware-dependent.
|
2012-02-22 20:58:23 +00:00
|
|
|
However, a README file should be present in the BSP Layer that explains how to use
|
2010-12-15 21:26:13 +00:00
|
|
|
the kernels and images with the target hardware.
|
2010-12-14 00:21:12 +00:00
|
|
|
If pre-built binaries are present, source code to meet licensing requirements must also
|
2012-02-22 20:58:23 +00:00
|
|
|
exist in some form.
|
2010-12-14 00:21:12 +00:00
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id='bsp-filelayout-layer'>
|
2010-12-15 21:40:41 +00:00
|
|
|
<title>Layer Configuration File</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find this file in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-<bsp_name>/conf/layer.conf
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
The <filename>conf/layer.conf</filename> file identifies the file structure as a Yocto
|
|
|
|
Project layer, identifies the
|
2011-07-14 21:49:34 +00:00
|
|
|
contents of the layer, and contains information about how Yocto Project should use it.
|
2010-12-16 21:39:14 +00:00
|
|
|
Generally, a standard boilerplate file such as the following works.
|
2012-02-22 21:12:38 +00:00
|
|
|
In the following example, you would replace "<filename>bsp</filename>" and
|
|
|
|
"<filename>_bsp</filename>" with the actual name
|
|
|
|
of the BSP (i.e. <filename><bsp_name></filename> from the example template).
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2012-02-22 21:12:38 +00:00
|
|
|
# We have a conf and classes directory, add to BBPATH
|
2011-08-18 23:00:16 +00:00
|
|
|
BBPATH := "${BBPATH}:${LAYERDIR}"
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2012-02-22 21:12:38 +00:00
|
|
|
# We have a recipes directory, add to BBFILES
|
2011-08-18 23:00:16 +00:00
|
|
|
BBFILES := "${BBFILES} ${LAYERDIR}/recipes/*/*.bb \
|
|
|
|
${LAYERDIR}/recipes/*/*.bbappend"
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2011-08-18 23:00:16 +00:00
|
|
|
BBFILE_COLLECTIONS += "bsp"
|
|
|
|
BBFILE_PATTERN_bsp := "^${LAYERDIR}/"
|
2012-02-22 21:12:38 +00:00
|
|
|
BBFILE_PRIORITY_bsp = "6"
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
To illustrate the string substitutions, here are the last three statements from the Crown
|
|
|
|
Bay <filename>conf/layer.conf</filename> file:
|
|
|
|
<literallayout class='monospaced'>
|
|
|
|
BBFILE_COLLECTIONS += "crownbay"
|
|
|
|
BBFILE_PATTERN_crownbay := "^${LAYERDIR}/"
|
|
|
|
BBFILE_PRIORITY_crownbay = "6"
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2010-12-14 00:21:12 +00:00
|
|
|
This file simply makes BitBake aware of the recipes and configuration directories.
|
2012-02-22 21:12:38 +00:00
|
|
|
The file must exist so that the Yocto Project build system can recognize the BSP.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id="bsp-filelayout-machine">
|
2010-12-15 22:00:11 +00:00
|
|
|
<title>Hardware Configuration Options</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/conf/machine/*.conf
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
|
|
|
The machine files bind together all the information contained elsewhere
|
2011-07-14 21:49:34 +00:00
|
|
|
in the BSP into a format that the Yocto Project build system can understand.
|
2010-11-04 20:01:19 +00:00
|
|
|
If the BSP supports multiple machines, multiple machine configuration files
|
|
|
|
can be present.
|
2011-08-29 18:46:27 +00:00
|
|
|
These filenames correspond to the values to which users have set the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'><filename>MACHINE</filename></ulink> variable.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2010-12-14 00:21:12 +00:00
|
|
|
These files define things such as the kernel package to use
|
2012-03-08 21:17:14 +00:00
|
|
|
(<ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER</filename></ulink>
|
2012-02-22 22:13:29 +00:00
|
|
|
of virtual/kernel), the hardware drivers to
|
2010-11-04 20:01:19 +00:00
|
|
|
include in different types of images, any special software components
|
|
|
|
that are needed, any bootloader information, and also any special image
|
|
|
|
format requirements.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2012-02-22 22:13:29 +00:00
|
|
|
Each BSP Layer requires at least one machine file.
|
2010-11-04 20:01:19 +00:00
|
|
|
However, you can supply more than one file.
|
2011-08-29 18:46:27 +00:00
|
|
|
For example, in the Crown Bay BSP shown earlier in this section, the
|
|
|
|
<filename>conf/machine</filename> directory contains two configuration files:
|
|
|
|
<filename>crownbay.conf</filename> and <filename>crownbay-noemgd.conf</filename>.
|
|
|
|
The <filename>crownbay.conf</filename> file is used for the Crown Bay BSP
|
|
|
|
that supports the <trademark class='registered'>Intel</trademark> Embedded
|
|
|
|
Media and Graphics Driver (<trademark class='registered'>Intel</trademark>
|
|
|
|
EMGD), while the <filename>crownbay-noemgd.conf</filename> file is used for the
|
|
|
|
Crown Bay BSP that does not support the <trademark class='registered'>Intel</trademark>
|
|
|
|
EMGD.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2011-08-31 19:28:54 +00:00
|
|
|
This <filename>crownbay.conf</filename> file could also include
|
|
|
|
a hardware "tuning" file that is commonly used to
|
2012-02-22 22:13:29 +00:00
|
|
|
define the package architecture and specify
|
2011-08-31 19:28:54 +00:00
|
|
|
optimization flags, which are carefully chosen to give best
|
|
|
|
performance on a given processor.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
2011-08-31 19:28:54 +00:00
|
|
|
|
2010-11-04 20:01:19 +00:00
|
|
|
<para>
|
2011-08-31 19:28:54 +00:00
|
|
|
Tuning files are found in the <filename>meta/conf/machine/include</filename>
|
2012-02-22 22:13:29 +00:00
|
|
|
directory of the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-files'>Yocto Project Files</ulink>.
|
2012-02-22 22:13:29 +00:00
|
|
|
Tuning files can also reside in the BSP Layer itself.
|
|
|
|
For example, the <filename>ia32-base.inc</filename> file resides in the
|
|
|
|
<filename>meta-intel</filename> BSP Layer in <filename>conf/machine/include</filename>.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
To use an include file, you simply include them in the machine configuration file.
|
2011-08-31 19:28:54 +00:00
|
|
|
For example, the Crown Bay BSP <filename>crownbay.conf</filename> has the
|
2012-02-22 22:13:29 +00:00
|
|
|
following statements:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2011-08-31 19:28:54 +00:00
|
|
|
include conf/machine/include/tune-atom.inc
|
2012-02-22 22:13:29 +00:00
|
|
|
include conf/machine/include/ia32-base.inc
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id='bsp-filelayout-misc-recipes'>
|
2010-12-15 22:13:20 +00:00
|
|
|
<title>Miscellaneous Recipe Files</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/recipes-bsp/*
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-12-15 22:13:20 +00:00
|
|
|
|
|
|
|
<para>
|
2010-12-16 21:54:15 +00:00
|
|
|
This optional directory contains miscellaneous recipe files for the BSP.
|
|
|
|
Most notably would be the formfactor files.
|
2011-08-29 18:46:27 +00:00
|
|
|
For example, in the Crown Bay BSP there is the
|
|
|
|
<filename>formfactor_0.0.bbappend</filename> file, which is an append file used
|
|
|
|
to augment the recipe that starts the build.
|
|
|
|
Furthermore, there are machine-specific settings used during the build that are
|
|
|
|
defined by the <filename>machconfig</filename> files.
|
|
|
|
In the Crown Bay example, two <filename>machconfig</filename> files exist:
|
2012-02-24 23:44:44 +00:00
|
|
|
one that supports the
|
|
|
|
<trademark class='registered'>Intel</trademark> Embedded
|
|
|
|
Media and Graphics Driver (<trademark class='registered'>Intel</trademark>
|
|
|
|
EMGD) and one that does not:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay/machconfig
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor/crownbay-noemgd/machconfig
|
2011-08-18 23:00:16 +00:00
|
|
|
meta-crownbay/recipes-bsp/formfactor/formfactor_0.0.bbappend
|
|
|
|
</literallayout>
|
2010-12-15 22:13:20 +00:00
|
|
|
</para>
|
2010-12-16 21:54:15 +00:00
|
|
|
|
|
|
|
<note><para>
|
|
|
|
If a BSP does not have a formfactor entry, defaults are established according to
|
2012-02-24 22:57:10 +00:00
|
|
|
the formfactor configuration file that is installed by the main
|
|
|
|
formfactor recipe
|
|
|
|
<filename>meta/recipes-bsp/formfactor/formfactor_0.0.bb</filename>,
|
|
|
|
which is found in the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-files'>Yocto Project Files</ulink>.
|
2010-12-16 21:54:15 +00:00
|
|
|
</para></note>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-12-15 22:13:20 +00:00
|
|
|
|
2011-09-28 19:36:33 +00:00
|
|
|
<section id='bsp-filelayout-core-recipes'>
|
|
|
|
<title>Core Recipe Files</title>
|
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-09-28 19:36:33 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/recipes-core/*
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
2012-02-22 22:47:20 +00:00
|
|
|
This directory contains recipe files that are almost always necessary to build a
|
|
|
|
useful, working Linux image.
|
|
|
|
Thus, the term "core" is used to group these recipes.
|
2011-09-28 19:36:33 +00:00
|
|
|
For example, in the Crown Bay BSP there is the
|
2012-02-22 22:47:20 +00:00
|
|
|
<filename>task-core-tools-profile.bbappend</filename> file, which is an append file used
|
|
|
|
to recommend that the
|
|
|
|
<ulink url='http://sourceware.org/systemtap/wiki'>SystemTap</ulink>
|
|
|
|
package be included as a package when the image is built.
|
2011-09-28 19:36:33 +00:00
|
|
|
</para>
|
|
|
|
</section>
|
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id='bsp-filelayout-recipes-graphics'>
|
2010-12-15 22:25:34 +00:00
|
|
|
<title>Display Support Files</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-<bsp_name>/recipes-graphics/*
|
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-12-15 22:25:34 +00:00
|
|
|
|
|
|
|
<para>
|
2010-12-16 21:58:32 +00:00
|
|
|
This optional directory contains recipes for the BSP if it has
|
|
|
|
special requirements for graphics support.
|
2010-12-15 22:25:34 +00:00
|
|
|
All files that are needed for the BSP to support a display are kept here.
|
2012-02-22 23:09:28 +00:00
|
|
|
For example, the Crown Bay BSP contains two versions of the
|
|
|
|
<filename>xorg.conf</filename> file.
|
|
|
|
The version in <filename>crownbay</filename> builds a BSP that supports the
|
|
|
|
<trademark class='registered'>Intel</trademark> Embedded Media Graphics Driver (EMGD),
|
|
|
|
while the version in <filename>crownbay-noemgd</filename> builds
|
|
|
|
a BSP that supports Video Electronics Standards Association (VESA) graphics only:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay/xorg.conf
|
|
|
|
meta-crownbay/recipes-graphics/xorg-xserver/xserver-xf86-config/crownbay-noemgd/xorg.conf
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-12-15 22:25:34 +00:00
|
|
|
</para>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
2010-12-15 22:25:34 +00:00
|
|
|
|
2010-12-15 22:37:33 +00:00
|
|
|
<section id='bsp-filelayout-kernel'>
|
2010-12-15 22:29:36 +00:00
|
|
|
<title>Linux Kernel Configuration</title>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2012-02-22 20:48:38 +00:00
|
|
|
You can find these files in the BSP Layer at:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-<bsp_name>/recipes-kernel/linux/linux-yocto_*.bbappend
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
|
|
|
</para>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
These files append your specific changes to the kernel you are using.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
For your BSP, you typically want to use an existing Yocto Project kernel found in the
|
2012-03-08 21:17:14 +00:00
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-files'>Yocto
|
2012-02-24 23:44:44 +00:00
|
|
|
Project Files</ulink> at <filename>meta/recipes-kernel/linux</filename>.
|
2011-08-29 18:46:27 +00:00
|
|
|
You can append your specific changes to the kernel recipe by using a
|
2012-03-13 18:34:30 +00:00
|
|
|
similarly named append file, which is located in the BSP Layer (e.g.
|
2012-02-24 23:44:44 +00:00
|
|
|
the <filename>meta-<bsp_name>/recipes-kernel/linux</filename> directory).
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
2012-02-24 23:44:44 +00:00
|
|
|
Suppose the BSP uses the <filename>linux-yocto_3.0.bb</filename> kernel,
|
2010-12-17 22:53:40 +00:00
|
|
|
which is the preferred kernel to use for developing a new BSP using the Yocto Project.
|
2010-12-18 00:53:59 +00:00
|
|
|
In other words, you have selected the kernel in your
|
2011-08-29 18:46:27 +00:00
|
|
|
<filename><bsp_name>.conf</filename> file by adding the following statements:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
|
2011-08-29 18:46:27 +00:00
|
|
|
PREFERRED_VERSION_linux-yocto = "3.0%"
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2011-08-29 18:46:27 +00:00
|
|
|
You would use the <filename>linux-yocto_3.0.bbappend</filename> file to append
|
2010-12-17 16:30:35 +00:00
|
|
|
specific BSP settings to the kernel, thus configuring the kernel for your particular BSP.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
As an example, look at the existing Crown Bay BSP.
|
2010-12-18 00:53:59 +00:00
|
|
|
The append file used is:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2011-08-29 18:46:27 +00:00
|
|
|
meta-crownbay/recipes-kernel/linux/linux-yocto_3.0.bbappend
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2012-02-07 22:21:00 +00:00
|
|
|
The following listing shows the file.
|
|
|
|
Be aware that the actual commit ID strings in this example listing might be different
|
2012-02-24 23:44:44 +00:00
|
|
|
than the actual strings in the file from the <filename>meta-intel</filename>
|
2012-02-07 22:21:00 +00:00
|
|
|
Git source repository.
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2011-08-29 18:46:27 +00:00
|
|
|
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
|
|
|
|
|
2011-08-18 23:00:16 +00:00
|
|
|
COMPATIBLE_MACHINE_crownbay = "crownbay"
|
2011-08-29 18:46:27 +00:00
|
|
|
KMACHINE_crownbay = "yocto/standard/crownbay"
|
|
|
|
KERNEL_FEATURES_append_crownbay += " cfg/smp.scc"
|
|
|
|
|
|
|
|
COMPATIBLE_MACHINE_crownbay-noemgd = "crownbay-noemgd"
|
|
|
|
KMACHINE_crownbay-noemgd = "yocto/standard/crownbay"
|
|
|
|
KERNEL_FEATURES_append_crownbay-noemgd += " cfg/smp.scc"
|
|
|
|
|
2012-02-07 18:54:47 +00:00
|
|
|
SRCREV_machine_pn-linux-yocto_crownbay ?= "63c65842a3a74e4bd3128004ac29b5639f16433f"
|
|
|
|
SRCREV_meta_pn-linux-yocto_crownbay ?= "59314a3523e360796419d76d78c6f7d8c5ef2593"
|
2011-08-29 18:46:27 +00:00
|
|
|
|
2012-02-07 18:54:47 +00:00
|
|
|
SRCREV_machine_pn-linux-yocto_crownbay-noemgd ?= "63c65842a3a74e4bd3128004ac29b5639f16433f"
|
|
|
|
SRCREV_meta_pn-linux-yocto_crownbay-noemgd ?= "59314a3523e360796419d76d78c6f7d8c5ef2593"
|
2011-08-29 18:46:27 +00:00
|
|
|
</literallayout>
|
2012-02-24 23:44:44 +00:00
|
|
|
This append file contains statements used to support the Crown Bay BSP for both
|
|
|
|
<trademark class='registered'>Intel</trademark> EMGD and the VESA graphics.
|
2011-08-31 19:28:54 +00:00
|
|
|
The build process, in this case, recognizes and uses only the statements that
|
|
|
|
apply to the defined machine name - <filename>crownbay</filename> in this case.
|
|
|
|
So, the applicable statements in the <filename>linux-yocto_3.0.bbappend</filename>
|
|
|
|
file are follows:
|
2011-08-29 18:46:27 +00:00
|
|
|
<literallayout class='monospaced'>
|
|
|
|
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
|
|
|
|
|
|
|
|
COMPATIBLE_MACHINE_crownbay = "crownbay"
|
|
|
|
KMACHINE_crownbay = "yocto/standard/crownbay"
|
|
|
|
KERNEL_FEATURES_append_crownbay += " cfg/smp.scc"
|
|
|
|
|
2012-02-07 18:54:47 +00:00
|
|
|
SRCREV_machine_pn-linux-yocto_crownbay ?= "63c65842a3a74e4bd3128004ac29b5639f16433f"
|
|
|
|
SRCREV_meta_pn-linux-yocto_crownbay ?= "59314a3523e360796419d76d78c6f7d8c5ef2593"
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2012-03-13 18:34:30 +00:00
|
|
|
The append file defines <filename>crownbay</filename> as the compatible machine and
|
|
|
|
defines the <filename>KMACHINE</filename>.
|
|
|
|
The file also points to some configuration fragments to use by setting the
|
|
|
|
<filename>KERNEL_FEATURES</filename> variable.
|
|
|
|
The location for the configuration fragments is the kernel tree itself in the
|
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-build-directory'>Yocto Project Build
|
|
|
|
Directory</ulink> under <filename>linux/meta</filename>.
|
|
|
|
Finally, the append file points to the specific commits in the
|
|
|
|
<ulink url='&YOCTO_DOCS_DEV_URL;#yocto-project-files'>Yocto Project Files</ulink> Git
|
|
|
|
repository and the <filename>meta</filename> Git repository branches to identify the
|
|
|
|
exact kernel needed to build the Crown Bay BSP.
|
2010-11-04 20:01:19 +00:00
|
|
|
</para>
|
2010-12-17 22:53:40 +00:00
|
|
|
<para>
|
|
|
|
One thing missing in this particular BSP, which you will typically need when
|
2011-08-29 18:46:27 +00:00
|
|
|
developing a BSP, is the kernel configuration file (<filename>.config</filename>) for your BSP.
|
2010-12-17 22:53:40 +00:00
|
|
|
When developing a BSP, you probably have a kernel configuration file or a set of kernel
|
|
|
|
configuration files that, when taken together, define the kernel configuration for your BSP.
|
|
|
|
You can accomplish this definition by putting the configurations in a file or a set of files
|
|
|
|
inside a directory located at the same level as your append file and having the same name
|
|
|
|
as the kernel.
|
2011-08-29 18:46:27 +00:00
|
|
|
With all these conditions met simply reference those files in a
|
|
|
|
<filename>SRC_URI</filename> statement in the append file.
|
2010-12-17 22:53:40 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
|
|
|
For example, suppose you had a set of configuration options in a file called
|
2012-03-13 18:34:30 +00:00
|
|
|
<filename>myconfig</filename>.
|
2010-12-17 22:53:40 +00:00
|
|
|
If you put that file inside a directory named
|
2011-08-29 18:46:27 +00:00
|
|
|
<filename>/linux-yocto</filename> and then added
|
|
|
|
a <filename>SRC_URI</filename> statement such as the following to the append file,
|
|
|
|
those configuration
|
2010-12-17 22:53:40 +00:00
|
|
|
options will be picked up and applied when the kernel is built.
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2012-03-13 18:34:30 +00:00
|
|
|
SRC_URI += "file://myconfig"
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-12-17 22:53:40 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
|
|
|
As mentioned earlier, you can group related configurations into multiple files and
|
2011-08-29 18:46:27 +00:00
|
|
|
name them all in the <filename>SRC_URI</filename> statement as well.
|
2010-12-18 00:59:47 +00:00
|
|
|
For example, you could group separate configurations specifically for Ethernet and graphics
|
2011-08-29 18:46:27 +00:00
|
|
|
into their own files and add those by using a <filename>SRC_URI</filename> statement like the
|
2010-12-17 22:53:40 +00:00
|
|
|
following in your append file:
|
2011-08-18 23:00:16 +00:00
|
|
|
<literallayout class='monospaced'>
|
2012-03-13 18:34:30 +00:00
|
|
|
SRC_URI += "file://myconfig \
|
2010-12-17 22:53:40 +00:00
|
|
|
file://eth.cfg \
|
|
|
|
file://gfx.cfg"
|
2011-08-18 23:00:16 +00:00
|
|
|
</literallayout>
|
2010-12-17 22:53:40 +00:00
|
|
|
</para>
|
|
|
|
<para>
|
2012-03-13 18:34:30 +00:00
|
|
|
The <filename>FILESEXTRAPATHS</filename> variable is in boilerplate form in the
|
|
|
|
previous example in order to make it easy to do that.
|
|
|
|
This variable must be in your layer or BitBake will not find the patches or
|
|
|
|
configurations even if you have them in your <filename>SRC_URI</filename>.
|
|
|
|
The <filename>FILESEXTRAPATHS</filename> variable enables the build process to
|
|
|
|
find those configuration files.
|
2010-12-17 22:53:40 +00:00
|
|
|
</para>
|
2011-08-18 23:00:16 +00:00
|
|
|
<note>
|
|
|
|
<para>
|
2010-12-17 22:53:40 +00:00
|
|
|
Other methods exist to accomplish grouping and defining configuration options.
|
2012-03-13 18:34:30 +00:00
|
|
|
For example, if you are working with a local clone of the kernel repository,
|
|
|
|
you could checkout the kernel's <filename>meta</filename> branch, make your changes,
|
|
|
|
and then push the changes to the local bare clone of the kernel.
|
|
|
|
The result is that you directly add configuration options to the Yocto kernel
|
2011-08-29 18:46:27 +00:00
|
|
|
<filename>meta</filename> branch for your BSP.
|
2010-12-17 22:53:40 +00:00
|
|
|
The configuration options will likely end up in that location anyway if the BSP gets
|
|
|
|
added to the Yocto Project.
|
2012-02-07 19:01:04 +00:00
|
|
|
For an example showing how to change the BSP configuration, see the
|
2012-03-13 18:34:30 +00:00
|
|
|
"<ulink url='&YOCTO_DOCS_DEV_URL;#changing-the-bsp-configuration'>Changing the BSP Configuration</ulink>"
|
|
|
|
section in the Yocto Project Development Manual.
|
|
|
|
For a better understanding of working with a local clone of the kernel repository
|
|
|
|
and a local bare clone of the kernel, see the
|
|
|
|
"<ulink url='&YOCTO_DOCS_DEV_URL;#modifying-the-kernel-source-code'>Modifying the Kernel
|
|
|
|
Source Code</ulink>" section also in the Yocto Project Development Manual.</para>
|
2011-08-18 23:00:16 +00:00
|
|
|
<para>
|
2011-08-29 18:46:27 +00:00
|
|
|
In general, however, the Yocto Project maintainers take care of moving the
|
|
|
|
<filename>SRC_URI</filename>-specified
|
2012-03-13 18:34:30 +00:00
|
|
|
configuration options to the kernel's <filename>meta</filename> branch.
|
2010-12-17 22:53:40 +00:00
|
|
|
Not only is it easier for BSP developers to not have to worry about putting those
|
2010-12-18 00:59:47 +00:00
|
|
|
configurations in the branch, but having the maintainers do it allows them to apply
|
2010-12-17 22:53:40 +00:00
|
|
|
'global' knowledge about the kinds of common configuration options multiple BSPs in
|
|
|
|
the tree are typically using.
|
2011-08-18 23:00:16 +00:00
|
|
|
This allows for promotion of common configurations into common features.</para>
|
|
|
|
</note>
|
2010-12-15 22:37:33 +00:00
|
|
|
</section>
|
|
|
|
</section>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2012-03-22 19:43:51 +00:00
|
|
|
<section id='bsp-licensing-considerations'>
|
2012-03-22 13:20:52 +00:00
|
|
|
<title>BSP Licensing Considerations</title>
|
2012-03-22 19:43:51 +00:00
|
|
|
|
2010-11-04 20:01:19 +00:00
|
|
|
<para>
|
2012-03-22 19:43:51 +00:00
|
|
|
In some cases, a BSP contains separately licensed Intellectual Property (IP)
|
|
|
|
for a component or components.
|
|
|
|
For these cases, you are required to accept the terms of a commercial or other
|
|
|
|
type of license that requires some kind of explicit End User License Agreement (EULA).
|
|
|
|
Once the license is accepted, the Yocto Project build system can then build and
|
|
|
|
include the corresponding component in the final BSP image.
|
|
|
|
If the BSP is available as a pre-built image, you can download the image after
|
|
|
|
agreeing to the license or EULA.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
You could find that some separately licensed components that are essential
|
|
|
|
for normal operation of the system might not have an unencumbered (or free)
|
|
|
|
substitute.
|
|
|
|
Without these essential components, the system would be non-functional.
|
|
|
|
Then again, you might find that other licensed components that are simply
|
|
|
|
'good-to-have' or purely elective do have an unencumbered, free replacement
|
|
|
|
component that you can use rather than agreeing to the separately licensed component.
|
|
|
|
Even for components essential to the system, you might find an unencumbered component
|
|
|
|
that is not identical but will work as a less-capable version of the
|
|
|
|
licensed version in the BSP recipe.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
For cases where you can substitute a free component and still
|
|
|
|
maintain the system's functionality, the Yocto Project website's
|
|
|
|
<ulink url='&YOCTO_HOME_URL;/download/all?keys=&download_type=1&download_version='>BSP
|
|
|
|
Download Page</ulink> makes available de-featured BSPs
|
|
|
|
that are completely free of any IP encumbrances.
|
|
|
|
For these cases, you can use the substitution directly and
|
|
|
|
without any further licensing requirements.
|
|
|
|
If present, these fully de-featured BSPs are named appropriately
|
|
|
|
different as compared to the names of the respective
|
|
|
|
encumbered BSPs.
|
|
|
|
If available, these substitutions are your
|
|
|
|
simplest and most preferred options.
|
|
|
|
Use of these substitutions of course assumes the resulting functionality meets
|
|
|
|
system requirements.
|
|
|
|
</para>
|
2010-11-04 20:01:19 +00:00
|
|
|
|
2012-03-22 19:43:51 +00:00
|
|
|
<para>
|
|
|
|
If however, a non-encumbered version is unavailable or
|
|
|
|
it provides unsuitable functionality or quality, you can use an encumbered
|
|
|
|
version.
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<para>
|
|
|
|
A couple different methods exist within the Yocto
|
|
|
|
Project build system to satisfy the licensing
|
|
|
|
requirements for an encumbered BSP.
|
|
|
|
The following list describes them in order of preference:
|
|
|
|
<orderedlist>
|
|
|
|
<listitem><para><emphasis>Use the <filename>LICENSE_FLAGS</filename> variable
|
|
|
|
to define the Yocto Project recipes that have commercial or other types of
|
|
|
|
specially-licensed packages:</emphasis>
|
|
|
|
For each of those recipes, you can
|
|
|
|
specify a matching license string in a
|
|
|
|
<filename>local.conf</filename> variable named
|
|
|
|
<filename>LICENSE_FLAGS_WHITELIST</filename>.
|
|
|
|
Specifying the matching license string signifies that you agree to the license.
|
|
|
|
Thus, the build system can build the corresponding recipe and include
|
|
|
|
the component in the image.
|
|
|
|
See the
|
|
|
|
"<ulink url='&YOCTO_DOCS_REF_URL;#enabling-commercially-licensed-recipes'>Enabling
|
|
|
|
Commercially Licensed Recipes</ulink>" section in the Yocto Project Reference
|
|
|
|
Manual for details on how to use these variables.</para>
|
|
|
|
<para>If you build as you normally would, without
|
|
|
|
specifying any recipes in the
|
|
|
|
<filename>LICENSE_FLAGS_WHITELIST</filename>, the build stops and
|
|
|
|
provides you with the list of recipes that you have
|
|
|
|
tried to include in the image that need entries in
|
|
|
|
the <filename>LICENSE_FLAGS_WHITELIST</filename>.
|
|
|
|
Once you enter the appropriate license flags into the whitelist,
|
|
|
|
restart the build to continue where it left off.
|
|
|
|
During the build, the prompt will not appear again
|
|
|
|
since you have satisfied the requirement.</para>
|
|
|
|
<para>Once the appropriate license flags are whitelisted
|
|
|
|
in the <filename>LICENSE_FLAGS_WHITELIST</filename> variable, you
|
|
|
|
can build the encumbered image with no change at all
|
|
|
|
to the normal build process.</para></listitem>
|
|
|
|
<listitem><para><emphasis>Get a pre-built version of the BSP:</emphasis>
|
|
|
|
You can get this type of BSP by visiting the Yocto Project website's
|
|
|
|
<ulink url='&YOCTO_HOME_URL;/download'>Download</ulink>
|
|
|
|
page and clicking on "BSP Downloads".
|
|
|
|
You can download BSP tarballs that contain proprietary components
|
|
|
|
after agreeing to the licensing
|
|
|
|
requirements of each of the individually encumbered
|
|
|
|
packages as part of the download process.
|
|
|
|
Obtaining the BSP this way allows you to access an encumbered
|
|
|
|
image immediately after agreeing to the
|
|
|
|
click-through license agreements presented by the
|
|
|
|
website.
|
|
|
|
Note that if you want to build the image
|
|
|
|
yourself using the recipes contained within the BSP
|
|
|
|
tarball, you will still need to create an
|
|
|
|
appropriate <filename>LICENSE_FLAGS_WHITELIST</filename> to match the
|
|
|
|
encumbered recipes in the BSP.</para></listitem>
|
|
|
|
</orderedlist>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<note>
|
|
|
|
Pre-compiled images are bundled with
|
|
|
|
a time-limited kernel that runs for a
|
|
|
|
predetermined amount of time (10 days) before it forces
|
|
|
|
the system to reboot.
|
|
|
|
This limitation is meant to discourage direct redistribution
|
|
|
|
of the image.
|
|
|
|
You must eventually rebuild the image if you want to remove this restriction.
|
|
|
|
</note>
|
|
|
|
</section>
|
2010-11-04 20:01:19 +00:00
|
|
|
</chapter>
|