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Linux 内核的编译系统

时间:2014-06-15 16:05:05      阅读:351      评论:0      收藏:0      [点我收藏+]

标签:linux   kernel   makefile   

 

 

Linux  的编译使用 GNU make 工具来检查整个系统的文件和调用 gcc 工具以及脚本完成编译源代码生成 image 等操作。要了解整个编译系统,我们首先要了解 Linux 内核的 Makefile 文件。

 

Linux 的 编译系统包括 5 个部分

Makefile         顶层的 Makefile 文件
.config 内核配置文件
arch/$(ARCH)/Makefile 平台 Makefile 文件
scripts/Makefile.*                脚本规则
kbuild Makefiles             大概 500 多个其他的 Makefile 文件


Makefile

 

查看版本

 

在内核源代码的根目录有一个 Makefile 文件,这是编译内核的入口,不管执行配置还是编译,make 命令首先读取这个文件。这个文件首先指明了内核的版本:

我们这里是 3.10

VERSION = 3
PATCHLEVEL = 10
SUBLEVEL = 0
EXTRAVERSION =
NAME = Unicycling Gorilla

 

处理参数

 

然后处理 command line ,一共有 5  个 command line

V : 设定编译时,输出信息的等级,例如你可以用 make V=1, 查看编译时执行的所有命令,包括 gcc 参数都会打印出来

C :  代码检查,使用 sparse,检查源文件。

M : 指定不在当前目录(外部模块)的编译,也可以指定当前目录的子目录,那么将只会编译子目录的内容

O :指定编译生成的目标文件位置,当设置了 O 参数,内核生成的 obj 和 builtin 文件都会按照目录结构组织到 O 参数指定的目录里面

W: 使能外部 gcc 检查

 

这几个命令参数,在特定的情况下,将会非常有用,比如我们想编译一个单独的模块就经常使用 M 参数,用 M 指定模块的路径,make 的时候将会不编译整个内核,而编译我们需要的模块:(M 参数会覆盖  KBUILD_EXTMOD 变量)

make M=drivers/misc/
 LD      drivers/misc/eeprom/built-in.o
 CC [M]  drivers/misc/eeprom/eeprom_93cx6.o
 LD      drivers/misc/built-in.o
 Building modules, stage 2.
 MODPOST 1 modules
 CC      drivers/misc/eeprom/eeprom_93cx6.mod.o
 LD [M]  drivers/misc/eeprom/eeprom_93cx6.ko


 

O 参数的指定,会改变整个编译出来的文件的结构,例如哦我们有多个平台要编译,你就需要为每个平台 clone 一份内核代码了,只需要设置不同的输出路径即可:

make O=atmel,  make O=asus  (O 参数会覆盖 KBUILD_OUTPUT 变量),相应的文件也会生成在目标路径下,例如 uImage 就在 atmel/arch/arm/boot/uImage

 

获取信息

 

接下来系统就会获取交叉编译环境和选择不同的 gcc 和 bin 工具集

ARCH            ?= $(SUBARCH)
CROSS_COMPILE   ?= $(CONFIG_CROSS_COMPILE:"%"=%)


arch 变量设置目标平台, cross compile 设置交叉编译链。

 

伪目标

 

当系统信息获取成功,就可以执行编译命令了,每一个伪目标都可以作为一个编译命令:(大概有 40 个左右的伪目标),但是我们会使用到的并没有这么多,可以用 make help 查看我们使用的编译命令:

 make help
Cleaning targets:
  clean           - Remove most generated files but keep the config and
                    enough build support to build external modules
  mrproper        - Remove all generated files + config + various backup files
  distclean       - mrproper + remove editor backup and patch files
Configuration targets:
  config          - Update current config utilising a line-oriented program
  nconfig         - Update current config utilising a ncurses menu based program
  menuconfig      - Update current config utilising a menu based program
  xconfig         - Update current config utilising a QT based front-end
  gconfig         - Update current config utilising a GTK based front-end
  oldconfig       - Update current config utilising a provided .config as base
  localmodconfig  - Update current config disabling modules not loaded
  localyesconfig  - Update current config converting local mods to core
  silentoldconfig - Same as oldconfig, but quietly, additionally update deps
  defconfig       - New config with default from ARCH supplied defconfig
  savedefconfig   - Save current config as ./defconfig (minimal config)
  allnoconfig     - New config where all options are answered with no
  allyesconfig    - New config where all options are accepted with yes
  allmodconfig    - New config selecting modules when possible
  alldefconfig    - New config with all symbols set to default
  randconfig      - New config with random answer to all options
  listnewconfig   - List new options
  olddefconfig    - Same as silentoldconfig but sets new symbols to their default value
Other generic targets:
  all             - Build all targets marked with [*]
* vmlinux         - Build the bare kernel
* modules         - Build all modules
  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)
  firmware_install- Install all firmware to INSTALL_FW_PATH
                    (default: $(INSTALL_MOD_PATH)/lib/firmware)
  dir/            - Build all files in dir and below
  dir/file.[oisS] - Build specified target only
  dir/file.lst    - Build specified mixed source/assembly target only
                    (requires a recent binutils and recent build (System.map))
  dir/file.ko     - Build module including final link
  modules_prepare - Set up for building external modules
  tags/TAGS       - Generate tags file for editors
  cscope          - Generate cscope index
  gtags           - Generate GNU GLOBAL index
  kernelrelease   - Output the release version string
  kernelversion   - Output the version stored in Makefile
  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH
                    (default: /media/android/jiangxd/workspace/Miura/kernel/usr)
Static analysers
  checkstack      - Generate a list of stack hogs
  namespacecheck  - Name space analysis on compiled kernel
  versioncheck    - Sanity check on version.h usage
  includecheck    - Check for duplicate included header files
  export_report   - List the usages of all exported symbols
  headers_check   - Sanity check on exported headers
  headerdep       - Detect inclusion cycles in headers
  coccicheck      - Check with Coccinelle.
Kernel packaging:
  rpm-pkg             - Build both source and binary RPM kernel packages
  binrpm-pkg          - Build only the binary kernel package
  deb-pkg             - Build the kernel as a deb package
  tar-pkg             - Build the kernel as an uncompressed tarball
  targz-pkg           - Build the kernel as a gzip compressed tarball
  tarbz2-pkg          - Build the kernel as a bzip2 compressed tarball
  tarxz-pkg           - Build the kernel as a xz compressed tarball
  perf-tar-src-pkg    - Build perf-3.10.0.tar source tarball
  perf-targz-src-pkg  - Build perf-3.10.0.tar.gz source tarball
  perf-tarbz2-src-pkg - Build perf-3.10.0.tar.bz2 source tarball
  perf-tarxz-src-pkg  - Build perf-3.10.0.tar.xz source tarball
Documentation targets:
 Linux kernel internal documentation in different formats:
  htmldocs        - HTML
  pdfdocs         - PDF
  psdocs          - Postscript
  xmldocs         - XML DocBook
  mandocs         - man pages
  installmandocs  - install man pages generated by mandocs
  cleandocs       - clean all generated DocBook files
Architecture specific targets (arm):
* zImage        - Compressed kernel image (arch/arm/boot/zImage)
  Image         - Uncompressed kernel image (arch/arm/boot/Image)
* xipImage      - XIP kernel image, if configured (arch/arm/boot/xipImage)
  uImage        - U-Boot wrapped zImage
  bootpImage    - Combined zImage and initial RAM disk
                  (supply initrd image via make variable INITRD=<path>)
* dtbs          - Build device tree blobs for enabled boards
  install       - Install uncompressed kernel
  zinstall      - Install compressed kernel
  uinstall      - Install U-Boot wrapped compressed kernel
                  Install using (your) ~/bin/installkernel or
                  (distribution) /sbin/installkernel or
                  install to $(INSTALL_PATH) and run lilo

内容非常之多。这里只介绍几个常用的:

make menuconfig  图形化配置 config

make uImage          编译生成 uImage

make clean              删除大部分生成的文件,但是保留配置,以便可以编译模块

make distclean       删除所有生成的文件,补丁和配置,以及一些备份文件

make mrproper       删除所有生成的文件,补丁和配置


总的来说,顶层 Makefile 文件读取 config 文件生成 Linux 的两大目标文件 vmlinux 和 模块文件

Linux 内核的编译系统,布布扣,bubuko.com

Linux 内核的编译系统

标签:linux   kernel   makefile   

原文地址:http://blog.csdn.net/jingxia2008/article/details/30262853

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