Kernel 编译配置机制

VERSION = 3
PATCHLEVEL = 1
SUBLEVEL = 10
EXTRAVERSION =

%config: scripts_basic outputmakefile FORCE
	./mpatch_gen.sh
	$(Q)mkdir -p include/linux include/config
	$(Q)$(MAKE) $(build)=scripts/kconfig $@

PHONY += FORCE
FORCE:

# Basic helpers built in scripts/
PHONY += scripts_basic
scripts_basic:
	$(Q)$(MAKE) $(build)=scripts/basic
	$(Q)rm -f .tmp_quiet_recordmcount

###
# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.build obj=
# Usage:
# $(Q)$(MAKE) $(build)=dir
build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj

$(Q)$(MAKE) -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj=scripts/basic

src := $(obj)

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

__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) 	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) 	 $(subdir-ym) $(always)
	@:

PHONY += outputmakefile
# outputmakefile generates a Makefile in the output directory, if using a
# separate output directory. This allows convenient use of make in the
# output directory.
outputmakefile:
ifneq ($(KBUILD_SRC),)
	$(Q)ln -fsn $(srctree) source
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile 	    $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
endif

$(Q)$(MAKE) -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build  obj =scripts/kconfig menuconfig

menuconfig: $(obj)/mconf
	@scripts/checkconfig/check-config.sh
	@echo "*** jscese test  ‘$(Kconfig)‘"
	$< $(Kconfig)

# mconf:  Used for the menuconfig target
#         Utilizes the lxdialog package

ifdef KBUILD_KCONFIG
Kconfig := $(KBUILD_KCONFIG)
else
Kconfig := Kconfig

#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.
#
mainmenu "Linux/$ARCH $KERNELVERSION Kernel Configuration"

config SRCARCH
	string
	option env="SRCARCH"
    
source "arch/$SRCARCH/Kconfig"

target_ARM = $(shell cat .config | sed -n ‘/CONFIG_ARM=/p‘ | wc -l )
ifeq ($(target_ARM),1)
SUBARCH = arm
endif
ARCH	 ?= $(SUBARCH)
SRCARCH := $(ARCH)