ROM Android: Compile Kernel untuk MediaTek

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MTK Kernel Builder

2012-09-24 16:44:41| 分类: Android | 标签:kernel android makefile |举报 |字号 订阅 KConfig 流程 关心点1: kernel builder: @makeMtk

  make -f mediatek/build/makemtk.mk kernel

@mediatek/build/makemtk.mk

 kernel/build.sh 

@kernel/build.sh

 make mediatek-configs
 nice make ${makeflags} ${makedefs} silentoldconfig
 make ${makeflags} ${makejobs} ${makedefs}
  

mediatek-configs 目标是怎么回事? 原来:

   @kernel/Makefile  

include $(srctree)/arch/$(SRCARCH)/Makefile

   @kernel/arch/arm/Makefile

include ../mediatek/build/kernel/Makefile

   @mediatek/build/kernel/Makefile

.config mediatek-configs: $(MTK_ROOT_GEN_CONFIG)/kconfig $(MTK_ROOT_GEN_CONFIG)

       @echo "[COPY] $< --> $@"
       @cp $< $@
       @echo "[COPY] $< --> .config"
       @cp $< .config

@kernel/Kconfig

 source "arch/$SRCARCH/Kconfig"

@alps/kernel/arch/arm/Kconfig source "../mediatek/source/kernel/Kconfig" @alps/mediatek/source/kernel/Kconfig

31 if ARCH_MT6573
32 source "../mediatek/platform/mt6573/kernel/Kconfig/Kernel"
33 source "../mediatek/platform/mt6573/kernel/Kconfig/Board"
34 source "../mediatek/platform/mt6573/kernel/Kconfig/Drivers"
35 endif

@mediatek/platform/mt6573/kernel/Kconfig/Drivers

34 # Frame Buffer Related
35 menuconfig MTK_FB # FB_MT6516 FB_MT6573
36         bool "MediaTek Framebuffer Driver"
37         depends on FB
38         select FB_CFB_FILLRECT
39         select FB_CFB_COPYAREA
40         select FB_CFB_IMAGEBLIT
41         select FB_SOFT_CURSOR
42         ---help---
43           This selects the MediaTek(R) frame buffer driver.
44           If you want to use MediaTek(R) frame buffer diver, say Y here.
45           If unsure, say N.


关心点2: menuconfig是从哪里来?这样解释:

@alps/kernel/Makefile %config: scripts_basic outputmakefile FORCE

       $(Q)mkdir -p include/linux include/config
       $(Q)$(MAKE) $(build)=scripts/kconfig $@

关于最后的一条命令: 我打印出来是这样的效果: make -f scripts/Makefile.build obj=scripts/kconfig menuconfig

不知道$(build)变量是怎么计算出来的,后来发现是这样的: @kernel/Makefile 329 include $(srctree)/scripts/Kbuild.include

@kernel/scripts/Kbuild.include 156 ### 157 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj= 158 # Usage: 159 # $(Q)$(MAKE) $(build)=dir 160 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj

这样,就解析出来了上面的东西,

@kernel/scripts/Makefile.build

41 # The filename Kbuild has precedence over Makefile
42 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44 include $(kbuild-file)

这样就将 kernel/scripts/kconfig/Makefile 包含进去了。 查看文件 kernel/scripts/kconfig/Makefile 也就不用我多说了: @scripts/kconfig/Makefile xconfig: $(obj)/qconf

       $< $(Kconfig)

gconfig: $(obj)/gconf

       $< $(Kconfig)

menuconfig: $(obj)/mconf

       $< $(Kconfig)

config: $(obj)/conf

       $< --oldaskconfig $(Kconfig)

nconfig: $(obj)/nconf

       $< $(Kconfig)

oldconfig: $(obj)/conf

       $< --$@ $(Kconfig)

silentoldconfig: $(obj)/conf

       $(Q)mkdir -p include/generated
       $< --$@ $(Kconfig)
       cp -f include/generated/autoconf.h include/linux/autoconf.h


关心点3: .config 文件最终还会被更新一次:查看kernel log [COPY] ../mediatek/config/out/s816_bef/autoconfig/kconfig --> mediatek-configs [COPY] ../mediatek/config/out/s816_bef/autoconfig/kconfig --> .config

 HOSTCC  scripts/kconfig/conf.o
 SHIPPED scripts/kconfig/zconf.tab.c
 SHIPPED scripts/kconfig/lex.zconf.c
 SHIPPED scripts/kconfig/zconf.hash.c
 HOSTCC  scripts/kconfig/zconf.tab.o
 HOSTLD  scripts/kconfig/conf

scripts/kconfig/conf --silentoldconfig Kconfig

  1. configuration written to .config

cp -f include/generated/autoconf.h include/linux/autoconf.h

看kernel config 的程序 scripts/kconfig/conf 里面的代码有: scripts/kconfig/confdata.c:66: char *name = getenv("KCONFIG_CONFIG"); 而@Makefile 240:KCONFIG_CONFIG ?= .config export KCONFIG_CONFIG 可以获知这样的信息。


mediatek/config/out/s816_bef/autoconfig/kconfig: mediatek/config/mt6575/autoconfig/kconfig/platform

mediatek/config/common/autoconfig/kconfig/AEE mediatek/config/s816_bef/autoconfig/kconfig/project

mediatek/config/out/s816_bef/autoconfig @echo "[CONFIG] generate mediatek/config/out/s816_bef/autoconfig/kconfig" @cat mediatek/config/mt6575/autoconfig/kconfig/platform mediatek/config/common/autoconfig/kconfig/AEE

mediatek/config/s816_bef/autoconfig/kconfig/project | python mediatek/build/tools/config/merge-kconfig.py >

mediatek/config/out/s816_bef/autoconfig/kconfig

查了一下应该是: define .mtk.config.generate-auto-merge-rules .PHONY: mediatek-configs.$(1) mediatek-configs: mediatek-configs.$(1) mediatek-configs.$(1): $(2) $(2): PRIVATE_FILE_LIST := $(3) $(2): $(3) $(4)

       @echo "[CONFIG] generate $(2)"
       @cat $(3) | $(5) > $(2)

endef

应该是这样类似的$(call .mtk.config.generate-auto-merge-rules,kconfig,xx.xx.xx) 更有可能是这样的:$(call .mtk.config.generate-auto-rules,xx,xx,xx) 这个就要自己去验证了。


Referensi