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diff --git a/handbook/bsp.xml b/handbook/bsp.xml deleted file mode 100644 index 37dd166749..0000000000 --- a/handbook/bsp.xml +++ /dev/null @@ -1,287 +0,0 @@ -<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" -"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> - -<chapter id='bsp'> - - <title>Board Support Packages (BSP) - Developers Guide</title> - - <para> - A Board Support Package (BSP) is a collection of information which together - defines how to support a particular hardware device, set of devices or - hardware platform. It will include information about the hardware features - present on the device, kernel configuration information along with any - additional hardware drivers required and also any additional software - components required in addition to a generic Linux software stack for both - essential and optional platform features. - </para> - - <para> - The intend of this document is to define a structure for these components - so that BSPs follow a commonly understood layout allowing them to be - provided in a common way that everyone understands. It also allows end - users to become familiar with one common format and encourages standardisation - of software support of hardware. - </para> - - <para> - The proposed format does have elements that are specific to the Poky and - OpenEmbedded build systems. It is intended that this information can be - used by other systems besides Poky/OpenEmbedded and that it will be simple - to extract information and convert to other formats if required. The format - descriped can be directly accepted as a layer by Poky using its standard - layers mechanism but its important to recognise that the BSP captures all - the hardware specific details in one place in a standard format which is - useful for any person wishing to use the hardware platform regardless of - the build system in use. - </para> - - <para> - The BSP specification does not include a build system or other tooling, - it is concerned with the hardware specific components only. At the end - distribution point the BSP may be shipped combined with a build system - and other tools but it is important to maintain the distinction that these - are separate components which may just be combined in certain end products. - </para> - - <section id='bsp-filelayout'> - <title>Example Filesystem Layout</title> - - <para> - The BSP consists of a file structure inside a base directory, meta-bsp in this example where "bsp" is a placeholder for the machine or platform name. Examples of some files that it could contain are: - </para> - - <para> - <programlisting> -meta-bsp/ -meta-bsp/binary/zImage -meta-bsp/binary/poky-image-minimal.directdisk -meta-bsp/conf/layer.conf -meta-bsp/conf/machine/*.conf -meta-bsp/conf/machine/include/tune-*.inc -meta-bsp/packages/bootloader/bootloader_0.1.bb -meta-bsp/packages/linux/linux-bsp-2.6.50/*.patch -meta-bsp/packages/linux/linux-bsp-2.6.50/defconfig-bsp -meta-bsp/packages/linux/linux-bsp_2.6.50.bb -meta-bsp/packages/modem/modem-driver_0.1.bb -meta-bsp/packages/modem/modem-daemon_0.1.bb -meta-bsp/packages/image-creator/image-creator-native_0.1.bb -meta-bsp/prebuilds/ - - </programlisting> - </para> - - <para> - The following sections detail what these files and directories could contain. - </para> - - </section> - - <section id='bsp-filelayout-binary'> - <title>Prebuilt User Binaries (meta-bsp/binary/*)</title> - - <para> - This optional area cotains useful prebuilt kernels and userspace filesystem - images appropriate to the target system. Users could use these to get a system - running and quickly get started on development tasks. The exact types of binaries - present will be highly hardware dependent but a README file should be present - explaining how to use them with the target hardware. If prebuilt binaries are - present, source code to meet licensing requirements must also be provided in - some form. - </para> - - </section> - - <section id='bsp-filelayout-layer'> - <title>Layer Configuration (meta-bsp/conf/layer.conf)</title> - - <para> - This file identifies the structure as a Poky layer. This file identifies the - contents of the layer and how contains information about how Poky should use - it. In general it will most likely be a standard boilerplate file consisting of: - </para> - - <para> - <programlisting> -# We have a conf directory, add to BBPATH -BBPATH := "${BBPATH}${LAYERDIR}" - -# We have a packages directory, add to BBFILES -BBFILES := "${BBFILES} ${LAYERDIR}/packages/*/*.bb" - -BBFILE_COLLECTIONS += "meta-bsp" -BBFILE_PATTERN_meta-bsp := "^${LAYERDIR}/" -BBFILE_PRIORITY_meta-bsp = "5" - </programlisting> - </para> - - <para> - which simply makes bitbake aware of the packages and conf directories. - </para> - - <para> - This file is required for recognition of the BSP by Poky. - </para> - - </section> - - <section id='bsp-filelayout-machine'> - <title>Hardware Configuration Options (meta-bsp/conf/machine/*.conf)</title> - - <para> - The machine files bind together all the information contained elsewhere - in the BSP into a format that Poky/OpenEmbedded can understand it in. If - the BSP supports multiple machines, multiple machine configuration files - can be present. These filenames correspond to the values users set the - MACHINE variable to. - </para> - - <para> - These files would define things like which kernel package to use - (PREFERRED_PROVIDER of virtual/kernel), which hardware drivers to - 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> - At least one machine file is required for a Poky BSP layer but more than one may be present. - </para> - - </section> - - <section id='bsp-filelayout-tune'> - <title>Hardware Optimisation Options (meta-bsp/conf/machine/include/tune-*.inc)</title> - - <para> - These are shared hardware "tuning" definitions and are commonly used to - pass specific optimisation flags to the compiler. An example is - tune-atom.inc: - </para> - <para> - <programlisting> -BASE_PACKAGE_ARCH = "core2" -TARGET_CC_ARCH = "-m32 -march=core2 -msse3 -mtune=generic -mfpmath=sse" - </programlisting> - </para> - <para> - which defines a new package architecture called "core2" and uses the - optimisation flags specified which are carefully chosen to give best - performance on atom cpus. - </para> - <para> - The tune file would be included by the machine definition and can be - contained in the BSP or reference one from the standard core set of - files included with Poky itself. - </para> - <para> - These files are optional for a Poky BSP layer. - </para> - </section> - <section id='bsp-filelayout-kernel'> - <title>Linux Kernel Configuration (meta-bsp/packages/linux/*)</title> - - <para> - These files make up the definition of a kernel to use with this - hardware. In this case its a complete self contained kernel with its own - configuration and patches but kernels can be shared between many - machines as well. Taking some specific example files: - </para> - <para> - <programlisting> -meta-bsp/packages/linux/linux-bsp_2.6.50.bb - </programlisting> - </para> - <para> - which is the core kernel recipe which firstly details where to get the kernel - source from. All standard source code locations are supported so this could - be a release tarball, some git repository or source included in - the directory within the BSP itself. It then contains information about which - patches to apply and how to configure and build it. It can reuse the main - Poky kernel build class meaning the definitions here can remain very simple. - </para> - <para> - <programlisting> -linux-bsp-2.6.50/*.patch - </programlisting> - </para> - <para> - which are patches which may be applied against the base kernel, wherever - that may have been obtained from. - </para> - <para> - <programlisting> -meta-bsp/packages/linux/linux-bsp-2.6.50/defconfig-bsp - </programlisting> - </para> - <para> - which is the configuration information to use to configure the kernel. - </para> - <para> - Examples of kernel recipes are available in Poky itself. These files are - optional since a kernel from Poky itself could be selected although it - would be unusual not to have a kernel configuration. - </para> - </section> - - <section id='bsp-filelayout-packages'> - <title>Other Software (meta-bsp/packages/*)</title> - - <para> - This area includes other pieces of software which the hardware may need for best - operation. These are just examples of the kind of things that may be - encountered. The are standard .bb file recipes in the usual Poky format - so for examples, see standard Poky recipes. The source can be included directly, - referred to in source control systems or release tarballs of external software projects. - </para> - <para> - <programlisting> -meta-bsp/packages/bootloader/bootloader_0.1.bb - </programlisting> - </para> - <para> - Some kind of bootloader recipe which may be used to generate a new - bootloader binary. Sometimes these are included in the final image - format and needed to reflash hardware. - </para> - <para> - <programlisting> -meta-bsp/packages/modem/modem-driver_0.1.bb -meta-bsp/packages/modem/modem-daemon_0.1.bb - </programlisting> - </para> - <para> - These are examples of a hardware driver and also a hardware daemon which - may need to be included in images to make the hardware useful. "modem" - is one example but there may be other components needed like firmware. - </para> - <para> - <programlisting> -meta-bsp/packages/image-creator/image-creator-native_0.1.bb - </programlisting> - </para> - <para> - Sometimes the device will need an image in a very specific format for - its update mechanism to accept and reflash with it. Recipes to build the - tools needed to do this can be included with the BSP. - </para> - <para> - These files only need be provided if the platform requires them. - </para> - </section> - - <section id='bsp-filelayout-prebuilds'> - <title>Prebuild Data (meta-bsp/prebuilds/*)</title> - - <para> - The location can contains a precompiled representation of the source code - contained elsewhere in the BSP layer. It can be processed and used by - Poky to provide much faster build times assuming a compatible configuration is used. - </para> - - <para> - These files are optional. - </para> - - </section> - -</chapter> |