【Yocto】devtool修改源代码

末蓝、 2023-10-02 10:04 14阅读 0赞

## 说明 ##

本文接在[【Yocto】BitBake入门之镜像中的HelloWorld][Yocto_BitBake_HelloWorld]之后完成。

## 修改源代码 ##

如果想要修改Poky项目中的源代码，可以依赖于`devtool`工具，这里以修改busybox为例。

首先创建workspace：

jw@X1C:~/code/poky/build$ devtool create-workspace
    NOTE: Starting bitbake server...
    jw@X1C:~/code/poky/build$ tree workspace/
    
    workspace/
    ├── conf
    │   └── layer.conf
    └── README
    
    1 directory, 2 files

使用`devtool create-workspace`除了创建上述的workspace，还会修改`conf/bblayers.conf`，它的作用是将workspace作为一个Layer添加到项目中：

jw@X1C:~/code/poky/build$ cat conf/bblayers.conf 
    # POKY_BBLAYERS_CONF_VERSION is increased each time build/conf/bblayers.conf
    # changes incompatibly
    POKY_BBLAYERS_CONF_VERSION = "2"
    
    BBPATH = "${TOPDIR}"
    BBFILES ?= ""
    
    BBLAYERS ?= " \
      /home/jw/code/poky/meta \
      /home/jw/code/poky/meta-poky \
      /home/jw/code/poky/meta-yocto-bsp \
      /home/jw/code/poky/meta-mylayer \
      /home/jw/code/poky/build/workspace \
      "

还可以通过`bitbake-layers`查看：

jw@X1C:~/code/poky/build$ bitbake-layers show-layers
    NOTE: Starting bitbake server...
    layer                 path                                      priority
    ==========================================================================
    meta                  /home/jw/code/poky/meta                   5
    meta-poky             /home/jw/code/poky/meta-poky              5
    meta-yocto-bsp        /home/jw/code/poky/meta-yocto-bsp         5
    meta-mylayer          /home/jw/code/poky/meta-mylayer           6
    workspace             /home/jw/code/poky/build/workspace        99

其次就是添加配方到workspace目录：

jw@X1C:~/code/poky/build$ devtool modify busybox
    NOTE: Starting bitbake server...
    NOTE: Reconnecting to bitbake server...
    NOTE: Retrying server connection (#1)...
    Loading cache: 100% |########################################################################################################################################################################| Time: 0:00:00
    Loaded 1424 entries from dependency cache.
    INFO: SRC_URI contains some conditional appends/prepends - will create branches to represent these
    NOTE: Resolving any missing task queue dependencies
    
    Build Configuration:
    BB_VERSION           = "1.49.0"
    BUILD_SYS            = "x86_64-linux"
    NATIVELSBSTRING      = "universal"
    TARGET_SYS           = "x86_64-poky-linux"
    MACHINE              = "qemux86-64"
    DISTRO               = "poky"
    DISTRO_VERSION       = "3.2+snapshot-f13e17656248021debea6fe01564c40af27271d1"
    TUNE_FEATURES        = "m64 core2"
    TARGET_FPU           = ""
    meta                 
    meta-poky            
    meta-yocto-bsp       
    meta-mylayer         
    workspace            = "master:f13e17656248021debea6fe01564c40af27271d1"
    
    Initialising tasks: 100% |###################################################################################################################################################################| Time: 0:00:00
    Sstate summary: Wanted 0 Found 0 Missed 0 Current 20 (0% match, 100% complete)
    NOTE: Executing Tasks
    NOTE: Tasks Summary: Attempted 93 tasks of which 90 didn't need to be rerun and all succeeded.
    INFO: Adding local source files to srctree...
    INFO: Source tree extracted to /home/jw/code/poky/build/workspace/sources/busybox
    WARNING: SRC_URI is conditionally overridden in this recipe, thus several devtool-override-* branches have been created, one for each override that makes changes to SRC_URI. It is recommended that you make changes to the devtool branch first, then checkout and rebase each devtool-override-* branch and update any unique patches there (duplicates on those branches will be ignored by devtool finish/update-recipe)
    INFO: Using source tree as build directory since that would be the default for this recipe
    INFO: Recipe busybox now set up to build from /home/jw/code/poky/build/workspace/sources/busybox

这样busybox的代码就被下载到`build/workspace/sources/busybox`目录下了，这个时候在构建项目，则使用的是workspace目录下的源码，如下所示：

下一个就是修改源码，比如修改`coreutils/date.c`，增加helloworld打印：

puts("helloworld\n");

然后再构建项目，发现会报错：

jw@X1C:~/code/poky/build$ bitbake core-image-minimal
    Loading cache: 100% |########################################################################################################################################################################| Time: 0:00:00
    Loaded 1424 entries from dependency cache.
    Parsing recipes: 100% |######################################################################################################################################################################| Time: 0:00:01
    Parsing of 810 .bb files complete (809 cached, 1 parsed). 1424 targets, 42 skipped, 0 masked, 0 errors.
    NOTE: Resolving any missing task queue dependencies
    
    Build Configuration:
    BB_VERSION           = "1.49.0"
    BUILD_SYS            = "x86_64-linux"
    NATIVELSBSTRING      = "universal"
    TARGET_SYS           = "x86_64-poky-linux"
    MACHINE              = "qemux86-64"
    DISTRO               = "poky"
    DISTRO_VERSION       = "3.2+snapshot-f13e17656248021debea6fe01564c40af27271d1"
    TUNE_FEATURES        = "m64 core2"
    TARGET_FPU           = ""
    meta                 
    meta-poky            
    meta-yocto-bsp       
    meta-mylayer         
    workspace            = "master:f13e17656248021debea6fe01564c40af27271d1"
    
    Initialising tasks: 100% |###################################################################################################################################################################| Time: 0:00:01
    Sstate summary: Wanted 5 Found 1 Missed 4 Current 1088 (20% match, 99% complete)
    NOTE: Executing Tasks
    NOTE: busybox: compiling from external source tree /home/jw/code/poky/build/workspace/sources/busybox
    ERROR: busybox-1.32.0-r0 do_package: Error executing a python function in exec_python_func() autogenerated:
    
    The stack trace of python calls that resulted in this exception/failure was:
    File: 'exec_python_func() autogenerated', lineno: 2, function: <module>
         0001:
     *** 0002:ptest_update_alternatives(d)
         0003:
    File: '/home/jw/code/poky/meta/classes/ptest.bbclass', lineno: 98, function: ptest_update_alternatives
         0094:        for alt_name, alt_link, alt_target, _ in alternatives:
         0095:            # Some alternatives are for man pages,
         0096:            # check if the alternative is in PATH
         0097:            if os.path.dirname(alt_link) in bin_paths:
     *** 0098:                os.symlink(alt_target, os.path.join(ptest_bindir, alt_name))
         0099:}
         0100:
         0101:do_configure_ptest_base[dirs] = "${B}"
         0102:do_compile_ptest_base[dirs] = "${B}"
    Exception: FileExistsError: [Errno 17] File exists: '/bin/busybox.suid' -> '/home/jw/code/poky/build/tmp/work/core2-64-poky-linux/busybox/1.32.0-r0/package/usr/lib/busybox/ptest/bin/login'
    
    ERROR: Logfile of failure stored in: /home/jw/code/poky/build/tmp/work/core2-64-poky-linux/busybox/1.32.0-r0/temp/log.do_package.12918
    ERROR: Task (/home/jw/code/poky/meta/recipes-core/busybox/busybox_1.32.0.bb:do_package) failed with exit code '1'
    NOTE: Tasks Summary: Attempted 3096 tasks of which 3090 didn't need to be rerun and 1 failed.
    
    Summary: 1 task failed:
      /home/jw/code/poky/meta/recipes-core/busybox/busybox_1.32.0.bb:do_package
    Summary: There was 1 ERROR message shown, returning a non-zero exit code.

但是如果再次编译，又能够编译成功了：

运行镜像之后执行`date`命令，结果如下：

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAamlhbmd3ZWkwNTEy_size_20_color_FFFFFF_t_70_g_se_x_16_pic_center]

可以看到代码修改成功了。

[Yocto_BitBake_HelloWorld]: https://blog.csdn.net/jiangwei0512/article/details/120395912?spm=1001.2014.3001.5501
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAamlhbmd3ZWkwNTEy_size_20_color_FFFFFF_t_70_g_se_x_16_pic_center]: https://img-blog.csdnimg.cn/dcf60c8f4c974fd7a71c34809f416977.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBAamlhbmd3ZWkwNTEy,size_20,color_FFFFFF,t_70,g_se,x_16#pic_center