Yocto BSP 开发说明

Yocto BSP 开发说明

内容参考:http://www.yoctoproject.org/docs/2.0/bsp-guide/bsp-guide.html#bsp

简介:

一个BSP(BoardSupport Package)  定义了如何去支持一个或者一类特定的硬件设备,或者硬件平台.

1 BSP layers:

BSP layers 的命名: meta-bsp_name, 如meta-minnow, meta-raspberrypi, and meta-intel .

源码来源: http://git.yoctoproject.org/cgit/cgit.cgi

git clone git://git.yoctoproject.org/meta-minnow

向conf/bblayers.conf: BBLAYERS 添加BSP的layers 路径

2 从文件组织来说明BSPlayers

下面是可能存在差异的文件列表:

     meta-[code]bsp_name

/[/code]

     meta-[code]bsp_name

/

bsp_license_file

[/code]

     meta-[code]bsp_name

/README[/code]

     meta-[code]bsp_name

/README.sources[/code]

     meta-[code]bsp_name

/binary/

bootable_images

[/code]

     meta-[code]bsp_name

/conf/layer.conf[/code]

     meta-[code]bsp_name

/conf/machine/*.conf[/code]

     meta-[code]bsp_name

/recipes-bsp/*[/code]

    meta-[code]bsp_name
4000

/recipes-core/*[/code]

     meta-[code]bsp_name

/recipes-graphics/*[/code]

     meta-[code]bsp_name

/recipes-kernel/linux/linux-yocto_

kernel_rev

.bbappend[/code]
下面是eMenlow的文件列表:

     meta-emenlow/COPYING.MIT

     meta-emenlow/README

     meta-emenlow/README.sources

     meta-emenlow/binary/

     meta-emenlow/conf/

     meta-emenlow/conf/layer.conf

     meta-emenlow/conf/machine/

     meta-emenlow/conf/machine/emenlow-noemgd.conf

     meta-emenlow/recipes-bsp/

     meta-emenlow/recipes-bsp/formfactor/

     meta-emenlow/recipes-bsp/formfactor/formfactor/

     meta-emenlow/recipes-bsp/formfactor/formfactor_0.0.bbappend

     meta-emenlow/recipes-bsp/formfactor/formfactor/emenlow-noemgd/

     meta-emenlow/recipes-bsp/formfactor/formfactor/emenlow-noemgd/machconfig

     meta-emenlow/recipes-graphics/

     meta-emenlow/recipes-graphics/xorg-xserver

     meta-emenlow/recipes-graphics/xorg-xserver/xserver-xf86-config

     meta-emenlow/recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend

     meta-emenlow/recipes-graphics/xorg-xserver/xserver-xf86-config/emenlow-noemgd

     meta-emenlow/recipes-graphics/xorg-xserver/xserver-xf86-config/emenlow-noemgd/xorg.config

     meta-emenlow/recipes-kernel/

     meta-emenlow/recipes-kernel/linux/

     meta-emenlow/recipes-kernel/linux/linux-yocto-dev.bbappend

     meta-emenlow/recipes-kernel/linux/linux-yocto_3.14.bbappend

 

2.1  License Files

meta-bsp_name/bsp_license_file

eMenlow 的license 文件是COPYING.MIT.

还可以是MIT,BSD, GPLv* 等等.

2.2  README 

meta-bsp_name/README , 它需要提供如何启动的方法,最少也得包含依赖关系和联系方式.

2.3. README.sources

meta-bsp_name/README.sources , 它提供了BSP源代码的存储路径和来源地址.

2.4. Pre-built User Binaries

meta-bsp_name/binary/bootable_images ,
存储了已经编译好的二进制kernel和rootfs.

2.5. Layer Configuration File

meta-[code]bsp_name

/conf/layer.conf ,下面是模版,需要用真实的名字替换掉bsp.[/code]

     # We have a conf and classes directory, add to BBPATH

     BBPATH .= ":${LAYERDIR}"

     # We have a recipes directory, add to BBFILES

     BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \

             ${LAYERDIR}/recipes-*/*/*.bbappend"

     BBFILE_COLLECTIONS += "[code]bsp

"[/code]

     BBFILE_PATTERN_[code]bsp

= "^${LAYERDIR}/"[/code]

     BBFILE_PRIORITY_[code]bsp

= "6"[/code]

     LAYERDEPENDS_[code]bsp

= "intel"[/code]

2.6. Hardware Configuration Options

meta-[code]bsp_name

/conf/machine/*.conf[/code]
硬件的配置信息.

2.7. Miscellaneous BSP-Specific Recipe Files

meta-[code]bsp_name

/recipes-bsp/*[/code]
包含一些BSP特定的package.

2.8. Display Support Files

meta-bsp_name/recipes-graphics/*

它可以代表一类可以运行在该BSP上的package.

2.9. Linux Kernel Configuration

meta-bsp_name/recipes-kernel/linux/linux-yocto*.bbappend

它可以配置kernel信息.

3 发布BSP的需求和推荐

3.1. Released BSP Requirements

在GIT上发布一个BSP,我们需要严格按照BSP的书写格式填写相关的文件.

3.2. Released BSP Recommendations

发布BSP的可选项:  可启动的bootimage 以及 一个特定的yoctokernel recipes.

4 自定义一个BSP的recipe

在”xyz”中定义一个BSP相关的interfaces工具基于init-ifupdown_1.0.bb.

·       编辑init-ifupdown_1.0.bbappend

FILESEXTRAPATHS_prepend := "${THISDIR}/files:"

·       建立interfaces的存储位置

meta-xyz/recipes-core/init-ifupdown/files/xyz-machine-one/interfaces

如果BSP只支持一个硬件机器,可以改为: meta-xyz/recipes-core/init-ifupdown/files/interfaces

5 BSP的Licensing考虑事项

…

6 使用Yocto的BSP 工具

Yocto 工程已经包含了一系列的BSP 工具 : yocto-bsp 和  yocto-kernel .

6.1. Common Features

$ source oe-init-build-env build_dir

$ yocto-bsp help

$ yocto-bsp help create

6.2. 通过yocto-bsp工具创建BSPlayers

$ yocto-bsp list karch

     Architectures available:

         qemu

         mips64

         powerpc

         x86_64

         arm

         mips

         i386

$ yocto-bsp create myarm qemu

     Checking basic git connectivity...

     Done.

     Which qemu architecture would you like to use? [default: i386]

         1) i386    (32-bit)

         2) x86_64  (64-bit)

         3) ARM     (32-bit)

         4) PowerPC (32-bit)

         5) MIPS    (32-bit)

         6) MIPS64  (64-bit)

     3

     Would you like to use the default (3.19) kernel? (y/n) [default: y] y

     Do you need a new machine branch for this BSP (the alternative is to re-use an existing branch)? [y/n] [default: y]

     Getting branches from remote repo git://git.yoctoproject.org/linux-yocto-3.19.git...

     Please choose a machine branch to base your new BSP branch on: [default: standard/base]

         1) standard/arm-versatile-926ejs

         2) standard/base

         3) standard/beagleboard

         4) standard/beaglebone

         5) standard/ck

         6) standard/common-pc

         7) standard/crownbay

         8) standard/edgerouter

         9) standard/fsl-mpc8315e-rdb

         10) standard/mti-malta32

         11) standard/mti-malta64

         12) standard/qemuarm64

         13) standard/qemuppc

     1

     Would you like SMP support? (y/n) [default: y]

     Does your BSP have a touchscreen? (y/n) [default: n]

     Does your BSP have a keyboard? (y/n) [default: y]

     New qemu BSP created in meta-myarm

6.3. 通过yocto-kernel工具管理KernelPatches and Config

$ yocto-kernel --help

$ yocto-kernel patch add myarm ~/test.patch

     Added patches:

       test.patch

$ yocto-kernel patch add myarm ~/yocto-testmod.patch

     Added patches:

       yocto-testmod.patch

$ yocto-kernel patch list myarm

     The current set of machine-specific patches for myarm is:

       1) test.patch

       2) yocto-testmod.patch

$ yocto-kernel patch rm myarm

     Specify the patches to remove:

       1) test.patch

       2) yocto-testmod.patch

     1

     Removed patches:

       test.patch

$ yocto-kernel patch list myarm

     The current set of machine-specific patches for myarm is:

1)  yocto-testmod.patch

$ yocto-kernel config add myarm CONFIG_MISC_DEVICES=y

     Added item:

       CONFIG_MISC_DEVICES=y

     $ yocto-kernel config add myarm CONFIG_YOCTO_TESTMOD=y

     Added item:

       CONFIG_YOCTO_TESTMOD=y

$ yocto-kernel config list myarm

     The current set of machine-specific kernel config items for myarm is:

             1) CONFIG_MISC_DEVICES=y

             2) CONFIG_YOCTO_TESTMOD=y

$ yocto-kernel config rm myarm CONFIG_MISC_DEVICES=y