分类： Linux 系列2013-05-06 17:05 585人阅读 评论(0) 收藏 举报
1、make menuconfig VERSION = 2 PATCHLEVEL = 6 SUBLEVEL = 26 EXTRAVERSION = NAME = Rotary Wombat # *DOCUMENTATION*
# To see a list of typical targets execute \"make help\" # More info can be located in ./README
# Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. # Do not:
# o use make's built-in rules and variables
# (this increases performance and avoids hard-to-debug behaviour); # o print \"Entering directory ...\"; MAKEFLAGS += -rR --no-print-directory #-r禁止使用build-in规则
#--no-print-directory是:不要再屏幕上打印\"Entering directory..\" #记住变量SHELL,MAKEFLAGS在整个make的执行过程中 #始终被自动的传递给所有的子make
# We are using a recursive build, so we need to do a little thinking # to get the ordering right. #
# Most importantly: sub-Makefiles should only ever modify files in # their own directory. If in some directory we have a dependency on # a file in another dir (which doesn't happen often, but it's often # unavoidable when linking the built-in.o targets which finy # turn into vmlinux), we will call a sub make in that other dir, and # after that we are sure that everything which is in that other dir # is now up to date. #
# The only cases where we need to modify files which have global
# effects are thus separated out and done before the recursive # descending is started. They are now explicitly listed as the # prepare rule.
# To put more focus on warnings, be less verbose as default # Use 'make V=1' to see the full commands
ifdef V #v=1
ifeq (\"$(origin V)\
KBUILD_VERBOSE = $(V) #把V的值作为KBUILD_VERBOSE的值 endif endif
ifndef KBUILD_VERBOSE #即默认我们是不回显的 #回显即在命令执行前显示要执行的命令 KBUILD_VERBOSE = 0 endif
# 函数origin并不操作变量的值，只是告诉你你的这个变量是哪里来的。 # 语法是： $(origin ;)# origin函数的返回值有：
#\"undefined\"从来没有定义过、“default”是一个默认的定义、“ #\"environment\"是一个环境变量、 #\"file\"这个变量被定义在Makefile中 #\"command line\"这个变量是被命令行定义的 #\"override\"是被override指示符重新定义的 #\"automatic\"是一个命令运行中的自动化变量
# Call a source code checker (by default, \"sparse\") as part of the # C compilation.调用一个静态分析工具作为c编译器的 #部分
# Use 'make C=1' to enable checking of only re-compiled files. # Use 'make C=2' to enable checking of *all* source files, regardless # of whether they are re-compiled or not. #
# See the file \"Documentation/sparse.txt\" for more details, including # where to get the \"sparse\" utility. ifdef C
ifeq (\"$(origin C)\
KBUILD_CHECKSRC = $(C) endif endif
ifndef KBUILD_CHECKSRC KBUILD_CHECKSRC = 0 endif
#用M来指定外部模块的目录
# Use make M=dir to specify directory of external module to build # Old syntax make ... SUBDIRS=$PWD is still supported
# Setting the environment variable KBUILD_EXTMOD take precedence #识别这里是定义一个外部模块吗??
#当我们定义了M变量或者SUBDIRS时表示编译一个外部模块 ifdef SUBDIRS
KBUILD_EXTMOD ?= $(SUBDIRS) #?=为条件赋值操作符仅仅在变量还 #还没有定义的情况下有效 endif ifdef M
ifeq (\"$(origin M)\ KBUILD_EXTMOD := $(M) endif endif
# kbuild supports saving output files in a separate directory.
# To locate output files in a separate directory two syntaxes are supported. # In both cases the working directory must be the root of the kernel src. # 1) O=
# Use \"make O=dir/to/store/output/files/\" #
# 2) Set KBUILD_OUTPUT
# Set the environment variable KBUILD_OUTPUT to point to the directory # where the output files shall be placed.
# export KBUILD_OUTPUT=dir/to/store/output/files/
# make #
# The O= assignment takes precedence over the KBUILD_OUTPUT environment # variable.
# KBUILD_SRC is set on invocation of make in OBJ directory
# KBUILD_SRC is not intended to be used by the regular user (for now) ###################make 的最开始################### ####################################################
ifeq ($(KBUILD_SRC),)#如果KBUILD_SRC没有定义则进入下面一层即首次进入 #时一般都需要两次进入顶层Makefile #若定义了则不为空直接跳入下一步
# OK, Make called in directory where kernel src resides # Do we want to locate output files in a separate directory? ifdef O #把输出文件放在不同的文件夹内 ifeq (\"$(origin O)\
KBUILD_OUTPUT := $(O) #用于指定我们的输出文件的输出目录 endif endif
# That's our default target when none is given on the command line PHONY := _all _all:
# Cancel implicit rules on top Makefile取消隐式推倒规则
$(CURDIR)/Makefile Makefile: ;#remake 操作查看当前目录Makefile是否为最新 #CURDIR值为当前的内核源码目录current dir
#为GNU make使用的变量,CURDIR设置当前工作目录的路径名
ifneq ($(KBUILD_OUTPUT),) #如果输出目录不为空即设置了输出目录则检测 # Invoke a second make in the output directory, passing relevant variables # check that the output directory actually exists saved-output := $(KBUILD_OUTPUT)
KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)#这里是测试此目录是否
#存在,若存在则赋给K BUILD_OUTPUT
$(if $(KBUILD_OUTPUT),, /#这里的为空即表示输出目录不存在
$(error output directory \"$(saved-output)\" does not exist))#使用了error函数
#这里的if函数语法为:if, #或者是if,,
#make的环境变量叫MAKECMDGOALS 这个变量中会存放你所指定的 #终极目标的列表，如果在命令行上，你没有指定目标， #那么，这个变量是空值。
PHONY += $(MAKECMDGOALS) sub-make
#将任何在命令行中给出的目标放入变量MAKECMDGOALS
#这里filter-out是返回$(MAKECMDGOALS)中除了Makefile _all sub-make以外的 #其他文件;
$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make $(Q)@:#这里仅仅只是取消回显没有别的意思
#$(KBUILD_VERBOSE:1=)为变量替换，如果为1就替换为空 #if KBUILD_VERBOSE = 1 or KBUILD_VERBOSE is NULL #then
#$(MAKE) -C $(KBUILD_OUTPUT) //回显 #else
#@ $(MAKE) -C $(KBUILD_OUTPUT)//即不回显 #endif
sub-make: FORCE
$(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) /#KBUILD_OUTPUT==dir前面测试了 KBUILD_SRC=$(CURDIR) /
KBUILD_EXTMOD=\"$(KBUILD_EXTMOD)\" -f $(CURDIR)/Makefile /# $(filter-out _all sub-make,$(MAKECMDGOALS))#这里是表示要生成的目标
#make -C dir KBUILD_SRC=`pwd` KBUILD_EXTMOD=\"\" -f `pwd`/Makefile [Targets] #这里表示再次执行Makefile 但此时我们的KBUILD #此时再次执行完make后skip-makefile := 1从而
# Leave processing to above invocation of make结束子make返回根目录的make skip-makefile := 1
endif # ifneq ($(KBUILD_OUTPUT),)这里是ifneq endif # ifeq ($(KBUILD_SRC),)#这里是ifeq的结束处
#################################################### ####################################################
ifeq ($(skip-makefile),)#如果为空则开始分类执行!!!!!! #endif # skip-makefile在1813行处结束最大的ifeq结构 # If building an external module we do not care about the all: rule # but instead _all depend on modules PHONY += all #声明一个伪目标all
ifeq ($(KBUILD_EXTMOD),) #如果外部模块定义为空则_all依赖于all _all: all else
_all: modules #否则依赖于modules endif
srctree := $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))#看KBUILD_SRC是否为空, #设置源码目录 TOPDIR := $(srctree) #顶层目录
# FIXME - TOPDIR is obsolete, use srctree/objtree objtree := $(CURDIR) #CURDIR为make的默认环境变量 src := $(srctree) #源文件的目录也设置为当前目录 obj := $(objtree)#目标文件的输出目录设置当前目录
VPATH := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD)) #这里是说当前目录找不到源文件时的搜索目录 export srctree objtree VPATH TOPDIR #export用于要将指定变量输出给子make，
# SUBARCH tells the usermode build what the underlying arch is. That is set # first, and if a usermode build is happening, the \"ARCH=um\" on the command # line overrides the setting of ARCH below. If a native build is happening, # then ARCH is assigned, getting whatever value it gets normally, and # SUBARCH is subsequently ignored.
#这里是获取cpu的具体型号存在变量SUBARCH中 #sed -e s表示替换,这里表示出现i.86的用i386替换
#出现sun4u的用sparc64替换 #一般写成sed -e 's/i.86/i386' 用''括起来
SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ / -e s/arm.*/arm/ -e s/sa110/arm/ / -e s/s390x/s390/ -e s/parisc64/parisc/ / -e s/ppc.*/powerpc/ -e s/mips.*/mips/ / -e s/sh.*/sh/ )
# Cross compiling and selecting different set of gcc/bin-utils # --------------------------------------------------------------------------- #
# When performing cross compilation for other architectures ARCH shall be set # to the target architecture. (See archMakefile
export KBUILD_BUILDHOST := $(SUBARCH) #这里是把宿主机的cpu结构导出到 #KBUILD_BUILDHOST变量,并传入子make ARCH ?= $(SUBARCH) # 设置变量 ARCH 的方法有两种，
# 一：在命令行中 如： make ARCH=ia64 ； # 二：设置环境变量，在环境变量中默认 #的 ARCH 的值是执行 make 的 cpu 架构
# \"?=\"表示为ARCH 条件赋值如果ARCH前面没有赋值则这里赋值 #成功,否则不重新赋值
CROSS_COMPILE ?= #交叉编译工具的设置在嵌入式系统 #经常要修改此处设置交叉编译器的路径 # Architecture as present in compile.h UTS_MACHINE := $(ARCH) SRCARCH := $(ARCH)
# Additional ARCH settings for x86 ifeq ($(ARCH),i386) SRCARCH := x86 endif
ifeq ($(ARCH),x86_64) SRCARCH := x86 endif
KCONFIG_CONFIG ?= .config #这里是生成的配置文件
# SHELL used by kbuild 这里shel中的if [ -x file ]测试file是否可执行 CONFIG_SHELL := $(shell if [ -x \"$$BASH\" ]; then echo $$BASH; / else if [ -x /bin/bash ]; then echo /bin/bash; / else echo sh; fi ; fi) HOSTCC = gcc HOSTCXX = g++
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer HOSTCXXFLAGS = -O2
# Decide whether to build built-in, modular, or both. # Normally, just do built-in. KBUILD_MODULES := KBUILD_BUILTIN := 1
# If we have only \"make modules\编译内置对象 # When we're building modules with modversions, we need to consider # the built-in objects during the descend as well, in order to # make sure the checksums are up to date before we record them. #如果执行”make modules”则这里在这里重新处理KBUILD_BUILTIN :=1 ifeq ($(MAKECMDGOALS),modules)
KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1) endif
# If we have \"make modules\# in addition to whatever we do anyway.
# Just \"make\" or \"make all\" shall build modules as well
#如果执行\"make all\中任一个命令 #则在这里重新处理KBUILD_MODULES
ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)#filter过滤出指定的字符串 #这里表示如果不为空则编译模块 KBUILD_MODULES := 1 endif
ifeq ($(MAKECMDGOALS),) KBUILD_MODULES := 1 endif
export KBUILD_MODULES KBUILD_BUILTIN #导出变量给子make
export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
# Beautify output 格式化的回显控制
# --------------------------------------------------------------------------- #
# Normally, we echo the whole command before executing it. By making # that echo $($(quiet)$(cmd)), we now have the possibility to set # $(quiet) to choose other forms of output instead, e.g. #
# quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
# cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
#
# If $(quiet) is empty, the whole command will be printed.表示如果为空则完全回显 # If it is set to \"quiet_\表示只有版本显示
# If it is set to \"silent_\如果$(quiet)=silent表示完全不回显
# the variable $(silent_cmd_cc_o_c) doesn't exist. #
# A simple variant is to prefix commands with $(Q) - that's useful..$(Q)用作前缀,如果$(Q)=@表示
# for commands that shall be hidden in non-verbose mode. 不回显,为空表示回显 #
# $(Q)ln $@ :<
#
# If KBUILD_VERBOSE equals 0 then the above command will be hidden. # If KBUILD_VERBOSE equals 1 then the above command is displayed. ifeq ($(KBUILD_VERBOSE),1) #这里就是定义是否要回显 quiet =
Q = #不以@开头表示回显 else quiet=quiet_
Q = @ #这里以@开头表示不回显 endif
# If the user is running make -s (silent mode), suppress echoing of # commands
ifneq ($(findstring s,$(MAKEFLAGS)),)
#如果MAKEFLAGS中带了-s表示完全不要回显 quiet=silent_ endif
export quiet Q KBUILD_VERBOSE #导出子make
# Look for make include files relative to root of kernel src MAKEFLAGS += --include-dir=$(srctree)
# We need some generic definitions (do not try to remake the file). $(srctree)/scripts/Kbuild.include: ;
#这里执行remake操作请看GNU make 流程
include $(srctree)/scripts/Kbuild.include #这里是文件包含 #Kbuild.include 这里定义了大量通用的函数和变量 #重点!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
# Make variables (CC, etc...)
#这里是设置编译连接的默认程序,都是变量赋值操作 AS = $(CROSS_COMPILE)as LD = $(CROSS_COMPILE)ld CC = $(CROSS_COMPILE)gcc CPP = $(CC) -E
AR = $(CROSS_COMPILE)ar NM = $(CROSS_COMPILE)nm STRIP = $(CROSS_COMPILE)strip OBJCOPY = $(CROSS_COMPILE)objcopy OBJDUMP = $(CROSS_COMPILE)objdump AWK = awk
GENKSYMS = scripts/genksyms/genksyms DEPMOD = /sbin/depmod KALLSYMS = scripts/kallsyms PERL = perl
CHECK = sparse #默认的字符串检查
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise $(CF)
MODFLAGS = -DMODULE
CFLAGS_MODULE = $(MODFLAGS) AFLAGS_MODULE = $(MODFLAGS) LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL =
# Use LINUXINCLUDE when you must reference the include/ directory. # Needed to be compatible with the O= option LINUXINCLUDE := -Iinclude /
$(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include) / -include include/linux/autoconf.h
KBUILD_CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs / -fno-strict-aliasing -fno-common / -Werror-implicit-function-declaration KBUILD_AFLAGS := -D__ASSEMBLY__
# Read KERNELRELEASE from include/config/kernel.release (if it exists) KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)#
KERNELVERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION) export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
export CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE # When compiling out-of-tree modules, put MODVERDIR in the module # tree rather than in the kernel tree. The kernel tree might # even be read-only.
export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions # Files to ignore in find ... statements
RCS_FIND_IGNORE := /( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS -o -name .pc -o -name .hg -o -name .git /) -prune -o
export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn --exclude CVS --exclude .pc --exclude .hg --exclude .git #
===========================================================================
# Rules shared between *config targets and build targets
# Basic helpers built in scripts这里生成基本的scripts配置工具fixdep docproc两个/ PHONY += scripts_basic #定义一个伪目标 scripts_basic: #该伪目标要执行的操作 $(Q)$(MAKE) $(build)=scripts/basic
#build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj 定义在Kbuild.include中我们在前面 #包含了该文件
#src := $(obj)因为我们Makefile.build中需要带入参数obj用于赋给src #这里会执行.../scripts/Makefile.build 文件=========================== #Makefile.build中包含了scripts/basic/Makefile
# To avoid any implicit rule to kick in, define an empty command. scripts/basic/%: scripts_basic ; PHONY += outputmakefile
# outputmakefile generates a Makefile in the output directory, if using a # separate output directory. This allows convenient use of make in the # output directory. outputmakefile:
ifneq ($(KBUILD_SRC),) #$(CONFIG_SHELL)即被设置为/bin/sh或者其它shell $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile /#这里的用shell执行mkmakefile
$(srctree) $(objtree) $(VERSION) $(PATCHLEVEL) #并在输出目录中输出 #这个规则的命令运行一个shell脚本scripts/mkmakefile， #并传递四个参数。这个脚本主要是在$(objtree)参数指定的目录中 #生成一个Makefile文件。由于这里KBUILD_SRC为空， #所以这个脚本并不会被执行 endif
# To make sure we do not include .config for any of the *config targets # catch them early, and hand them over to scripts/kconfig/Makefile # It is allowed to specify more targets when calling make, including # mixing *config targets and build targets. # For example 'make oldconfig all'.
# Detect when mixed targets is specified, and make a second invocation # of make so .config is not included in this case either (for *config). #GNU configure 中的build/target和host的区别 #build就是现在使用的机器,即编译平台
#host就是我们的目标机,编译好的程序运行的平台 #target一般在构建编译本身的时候(gcc),采用target no-dot-config-targets := clean mrproper distclean / cscope TAGS tags help %docs check% / include/linux/version.h headers_% / kernelrelease kernelversion #这里是默认值,
config-targets := 0#如果有config %config则为1
mixed-targets := 0#当有config %config 还有其它目标时为1 dot-config := 1 #当有config %config时肯定为1 #根据输出参数修改 #make后面的目标包括三类:
#(1)和.config无关的目标即(no_dot_config-targets)比如:clean,mrproper,distclean, # headers_install,kernelrelease,kernelversion等等； #(2)和.config相关的目标dot_config
# a:配置目标(config targets)主要是产生.config文件
# b:构建目标(build targets)主要是使用.config像all,vmlinux,modules,zImage,等等
#(3)single targets
# 上面没有列出的,如:dir/,dir/file，dir/file.ko
ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)#如果我们命令行目标CMDGOALS
#有任何clean之类的命令
ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)#且除了clean之类目标外为空
#那么标识应该删除.config文件 dot-config := 0 endif endif
ifeq ($(KBUILD_EXTMOD),)
ifneq ($(filter config %config,$(MAKECMDGOALS)),)#这里就是匹配我们命令行 #中是否有menuconfig/xconfig等有则表示 #这是一条配置命令,因而config-targets置1 #标识应该生成.config文件 config-targets := 1
ifneq ($(filter-out config %config,$(MAKECMDGOALS)),)#如果不仅有config目标
#还有别的目标,表示为混合目标模式 mixed-targets := 1 endif endif endif
# ============混合模式则则执行以下规则=========== ifeq ($(mixed-targets),1) #如果是混合模式则则执行以下规则 # We're called with mixed targets (*config and build targets). # Handle them one by one.
#%代表make 后带任何目标都执行该命令
#那就是 %:: FORCE
$(Q)$(MAKE) -C $(srctree) KBUILD_SRC= $@
#从代码中可以看出，这里使用了一个双冒号的模式匹配规则。 #百分号代表任何目标都使用这个规则，其中
#$(srctree) 为内核代码树所在目 录 ， KBUILD_SRC 定义为空。 #所以如果 make 命令为 ： make s3c2410_defconfig all #那么构建系统就会分别执行下面两条命令：
#make -C $(srctree) KBUILD_SRC= s3c2410_defconfig #make -C $(srctree) KBUILD_SRC= all #这其实和简单的用手动的输入两条连续命令
#(make s3c2410_defconfig 和 make all) 是一样效果的。
# ============%config targe配置时执行以下规则=========== #这里是%config target时执行的规则!!!!!!!!!!!!!!!!!!!!!!!!!! else
ifeq ($(config-targets),1) #
===========================================================================
# *config targets only - make sure prerequisites are updated, and descend # in scripts/kconfig to make the *config target
# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed. # KBUILD_DEFCONFIG may point out an alternative default configuration # used for 'make defconfig'
include $(srctree)/arch/$(SRCARCH)/Makefile#直接包含平台架构下 #的makefile export KBUILD_DEFCONFIG
###############执行make menuconfig的入口点##################### #生配置工具,根据我们的kconfig
config %config: scripts_basic outputmakefile FORCE $(Q)mkdir -p include/linux include/config $(Q)$(MAKE) $(build)=scripts/kconfig $@
#在顶层目录执行”make menuconfig”会执行顶层Makefile 第415行的规则 #config %config: scripts_basic outputmakefile FORCE #$(Q)mkdir -p include/linux include/config #$(Q)$(MAKE) $(build)=scripts/kconfig $@
#这里\"menuconfig\"与模式\"%config”匹配。所以其执行的规则如下： #menuconfig: scripts_basic outputmakefile FORCE #$(Q)mkdir -p include/linux include/config #$(Q)$(MAKE) $(build)=scripts/kconfig menuconfig #$@目标变量
#build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj #之所以我们引用$(build)=...每次都要是build带一个等于号的 #的原因就是因为我们的变量后面带了一个obj用于指定 #我们的obj目录是哪里!!!!!!!!!!!!
#这个规则有三个依赖：scripts_basic、outputmakefile、FORCE
#PHONY += scripts_basic #定义一个伪目标 #scripts_basic: #该伪目标要执行的操作 # $(Q)$(MAKE) $(build)=scripts/basic
#build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj #之所以我们引用$(build)=...每次都要是build带一个等于号的 #的原因就是因为我们的变量后面带了一个obj用于指定 #我们的obj目录是哪里!!!!!!!!!!!!
#============================================== #============================================== #这个命令依然是执行scripts/Makefile.build这个makefile文件。 #并执行它里面$@表示menuconfig的规则。根据上面的分析， #在Makefile.build会包含scripts/kconfig/Makefile文件!!!!!!!!!!!!!。 #然后执行以menuconfig为目标的规则， #在scripts/kconfig/Makefile的13行定义 #menuconfig: $(obj)/mconf # $< arch/$(ARCH)/Kconfig
#即$<表示依赖集$(obj)/mconf这个是一个解析Kconfig的程序 #arch/$(ARCH)/Kconfig 是被解析的文件
# ===============编译模块或者目标时目标========================= # Build targets only - this includes vmlinux, arch specific targets, clean # targets and others. In general all targets except *config targets. else
ifeq ($(KBUILD_EXTMOD),) # # Additional helpers built in scripts/
# Carefully list dependencies so we do not try to build scripts twice # in parallel PHONY += scripts
scripts: scripts_basic include/config/auto.conf $(Q)$(MAKE) $(build)=$(@)
#这里生成scripts_basic include/config/auto.conf
# Objects we will link into vmlinux / subdirs we need to visit init-y := init/
drivers-y := drivers/ sound/ net-y := net/ libs-y := lib/ core-y := usr/
endif # KBUILD_EXTMOD
ifeq ($(dot-config),1)#若.config已经被配置,则可包含产生的auto.conf文件 # Read in config
-include include/config/auto.conf ifeq ($(KBUILD_EXTMOD),)
# Read in dependencies to all Kconfig* files, make sure to run # oldconfig if changes are detected. -include include/config/auto.conf.cmd
# To avoid any implicit rule to kick in, define an empty command $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
# If .config is newer than include/config/auto.conf, someone tinkered # with it and forgot to run make oldconfig.
# if auto.conf.cmd is missing then we are probably in a cleaned tree so # we execute the config step to be sure to catch updated Kconfig files #这里是生成我们的需要的三个文件
include/config/auto.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
$(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig else
# external modules needs include/linux/autoconf.h and include/config/auto.conf # but do not care if they are up-to-date. Use auto.conf to trigger the test PHONY += include/config/auto.conf include/config/auto.conf:
$(Q)test -e include/linux/autoconf.h -a -e $@ || ( / echo; /
echo \" ERROR: Kernel configuration is invalid.\"; / echo \" include/linux/autoconf.h or $@ are missing.\"; /
echo \" Run 'make oldconfig && make prepare' on kernel src to fix it.\"; / echo; / /bin/false)
endif # KBUILD_EXTMOD else
# Dummy target needed, because used as prerequisite include/config/auto.conf: ; endif # $(dot-config)
#==============the read targets starts====================== #==============vmlinux all modules and other targets ============ # The all: target is the default when no target is given on the # command line.
# This allow a user to issue only 'make' to build a kernel including modules # Defaults vmlinux but it is usually overridden in the arch makefile all: vmlinux #这个是默认的目标
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += -Os else
KBUILD_CFLAGS += -O2 endif
ifneq (CONFIG_FRAME_WARN,0)
KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN}) endif
# Force gcc to behave correct even for buggy distributions # Arch Makefiles may override this setting
KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector) include $(srctree)/arch/$(SRCARCH)/Makefile ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls else
KBUILD_CFLAGS += -fomit-frame-pointer endif
ifdef CONFIG_DEBUG_INFO KBUILD_CFLAGS += -g KBUILD_AFLAGS += -gdwarf-2 endif
# We trigger additional mismatches with less inlining ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once) endif
# arch Makefile may override CC so keep this after arch Makefile is included NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) CHECKFLAGS += $(NOSTDINC_FLAGS) # warn about C99 declaration after statement
KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) # disable pointer signed / unsigned warnings in gcc 4.0 KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments # But warn user when we do so warn-assign = /
$(warning \"WARNING: Appending $$K$(1) ($(K$(1))) from $(origin K$(1)) to kernel $$$(1)\")
ifneq ($(KCPPFLAGS),)
$(call warn-assign,CPPFLAGS)
KBUILD_CPPFLAGS += $(KCPPFLAGS) endif
ifneq ($(KAFLAGS),)
$(call warn-assign,AFLAGS)
KBUILD_AFLAGS += $(KAFLAGS) endif
ifneq ($(KCFLAGS),)
$(call warn-assign,CFLAGS) KBUILD_CFLAGS += $(KCFLAGS) endif
# Use --build-id when available.
LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,/ $(call ld-option, -Wl$(comma)--build-id,)) LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID) LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
# Default kernel image to build when no specific target is given. # KBUILD_IMAGE may be overruled on the command line or # set in the environment
# Also any assignments in arch/$(ARCH)/Makefile take precedence over # this default value
export KBUILD_IMAGE ?= vmlinux #
# INSTALL_PATH specifies where to place the updated kernel and system map # images. Default is /boot, but you can set it to other values export INSTALL_PATH ?= /boot #默认的安装目录 #
# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory # relocations required by build roots. This is not defined in the # makefile but the argument can be passed to make if needed. #
MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB #
# INSTALL_MOD_STRIP, if defined, will cause modules to be # stripped after they are installed. If INSTALL_MOD_STRIP is '1', then # the default option --strip-debug will be used. Otherwise,
# INSTALL_MOD_STRIP will used as the options to the strip command.
ifdef INSTALL_MOD_STRIP ifeq ($(INSTALL_MOD_STRIP),1) mod_strip_cmd = $(STRIP) --strip-debug else
mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP) endif # INSTALL_MOD_STRIP=1 else
mod_strip_cmd = true
endif # INSTALL_MOD_STRIP export mod_strip_cmd
#这里是编译的主体!!!!!!!!!!!!!!!!!!!!!!!
ifeq ($(KBUILD_EXTMOD),)#如果外部模块为空,即编译内核 core-y += kernel/ mm/ fs/ ipc/ security/ crypto/ block/ #此时我们的core-y目标需要添加各个模块 #vmlinux-dirs即我们编译内核需要添加的各个模块 #所在的内核目录
vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) / $(core-y) $(core-m) $(drivers-y) $(drivers-m) / $(net-y) $(net-m) $(libs-y) $(libs-m))) #这里的vmlinux即取目录名称
vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, /#sort is a sequence! $(init-n) $(init-) /
$(core-n) $(core-) $(drivers-n) $(drivers-) / $(net-n) $(net-) $(libs-n) $(libs-))))
#################重点############################### ################################################ ################################################ init-y := $(patsubst %/, %/built-in.o, $(init-y))#这里所有的init/都被 #init/built-in.o所替代
core-y := $(patsubst %/, %/built-in.o, $(core-y))#同上 #vmlinux-main即由各个目录下的build-in.o链接而成
drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y)) net-y := $(patsubst %/, %/built-in.o, $(net-y)) libs-y1 := $(patsubst %/, %/lib.a, $(libs-y)) libs-y2 := $(patsubst %/, %/built-in.o, $(libs-y)) libs-y := $(libs-y1) $(libs-y2) # Build vmlinux
# --------------------------------------------------------------------------- # vmlinux is built from the objects selected by $(vmlinux-init) and # $(vmlinux-main). Most are built-in.o files from top-level directories # in the kernel tree, others are specified in arch/$(ARCH)/Makefile. # Ordering when linking is important, and $(vmlinux-init) must be first. # # vmlinux # ^ # |
# +-< $(vmlinux-init)
# | +--< init/version.o + more # |
# +--< $(vmlinux-main)
# | +--< driver/built-in.o mm/built-in.o + more # |
# +-< kallsyms.o (see description in CONFIG_KALLSYMS section) #
# vmlinux version (uname -v) cannot be updated during normal
# descending-into-subdirs phase since we do not yet know if we need to # update vmlinux.
# Therefore this step is delayed until just before final link of vmlinux - # except in the kallsyms case where it is done just before adding the # symbols to the kernel. #
# System.map is generated to document addresses of all kernel symbols vmlinux-init := $(head-y) $(init-y)#head-y定义在/arch/xx/Makefile #head-y := arch/x86/kernel/head_$(BITS).o #head-y += arch/x86/kernel/head$(BITS).o #head-y += arch/x86/kernel/init_task.o
vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y)#the main body of linux kernel; vmlinux-all := $(vmlinux-init) $(vmlinux-main) vmlinux-lds := arch/$(SRCARCH)/kernel/vmlinux.lds #使用与架构相关的 #链接文件lds
export KBUILD_VMLINUX_OBJS := $(vmlinux-all)
# Rule to link vmlinux - also used during CONFIG_KALLSYMS # May be overridden by arch/$(ARCH)/Makefile
quiet_cmd_vmlinux__ ?= LD $@ #?=means the defualts if without other operation cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ / -T $(vmlinux-lds) $(vmlinux-init) / --start-group $(vmlinux-main) --end-group /
$(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^) # Generate new vmlinux version
quiet_cmd_vmlinux_version = GEN .version cmd_vmlinux_version = set -e; / if [ ! -r .version ]; then / rm -f .version; / echo 1 >.version; / else /
mv .version .old_version; /
expr 0$$(cat .old_version) + 1 >.version; / fi; /
$(MAKE) $(build)=init # Generate System.map quiet_cmd_sysmap = SYSMAP
cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap # Link of vmlinux
# If CONFIG_KALLSYMS is set .version is already updated # Generate System.map and verify that the content is consistent
# Use + in front of the vmlinux_version rule to silent warning with make -j2 # First command is ':' to allow us to use + in front of the rule #以下是一个命令包,即一组命令可能在多个规则中使用
#相同的一组命令,通过define来定义这组命令作为一个命令,以后 #在需要的规则中通过变量名直接引用!!!!!!!
define rule_vmlinux__ #这里是执行vmlinux的规则 :
$(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version)) $(call cmd,vmlinux__)
#cmd = @$(echo-cmd) $(cmd_$(1))
#即被展开为cmd_vmlinux__!!!!!!!!!!!!!!!=======
#而此命令为一个连接命令,如下!!!!!!!!========即我们连接命令 #cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ / # -T $(vmlinux-lds) $(vmlinux-init) / # --start-group $(vmlinux-main) --end-group /
# $(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^)
$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
$(Q)$(if $($(quiet)cmd_sysmap), #生成System.map / echo ' $($(quiet)cmd_sysmap) System.map' &&) / $(cmd_sysmap) $@ System.map; / if [ $$? -ne 0 ]; then / rm -f $@; / /bin/false; / fi;
$(verify_kallsyms) endef
#至此我们的vmlinux就链接完成了,接下来就是我们的bzImage了!!! ifdef CONFIG_KALLSYMS
# Generate section listing all symbols and add it into vmlinux $(kallsyms.o) # It's a three stage process:
# o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is # empty
# Running kallsyms on that gives us .tmp_kallsyms1.o with
# the right size - vmlinux version (uname -v) is updated during this step # o .tmp_vmlinux2 now has a __kallsyms section of the right size, # but due to the added section, some addresses have shifted. # From here, we generate a correct .tmp_kallsyms2.o # o The correct .tmp_kallsyms2.o is linked into the final vmlinux.
# o Verify that the System.map from vmlinux matches the map from # .tmp_vmlinux2, just in case we did not generate kallsyms correctly. # o If CONFIG_KALLSYMS_EXTRA_PASS is set, do an extra pass using # .tmp_vmlinux3 and .tmp_kallsyms3.o. This is only meant as a # temporary bypass to allow the kernel to be built while the # maintainers work out what went wrong with kallsyms. ifdef CONFIG_KALLSYMS_EXTRA_PASS last_kallsyms := 3 else
last_kallsyms := 2 endif
kallsyms.o := .tmp_kallsyms$(last_kallsyms).o
#以下是一个命令包,即一组命令可能在多个规则中使用
#相同的一组命令,通过define来定义这组命令作为一个命令,以后 #在需要的规则中通过变量名直接引用!!!!!!! define verify_kallsyms #这里是命令包名称
$(Q)$(if $($(quiet)cmd_sysmap), /
echo ' $($(quiet)cmd_sysmap) .tmp_System.map' &&) / $(cmd_sysmap) .tmp_vmlinux$(last_kallsyms) .tmp_System.map $(Q)cmp -s System.map .tmp_System.map || / (echo Inconsistent kallsyms data; /
echo Try setting CONFIG_KALLSYMS_EXTRA_PASS; / rm .tmp_kallsyms* ; /bin/false ) endef
# Update vmlinux version before link
# Use + in front of this rule to silent warning about make -j1 # First command is ':' to allow us to use + in front of this rule cmd_ksym_ld = $(cmd_vmlinux__) define rule_ksym_ld :
+$(call cmd,vmlinux_version) $(call cmd,vmlinux__)
$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd endef
# Generate .S file with all kernel symbols quiet_cmd_kallsyms = KSYM $@
cmd_kallsyms = $(NM) -n $< | $(KALLSYMS) /
$(if $(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
.tmp_kallsyms1.o .tmp_kallsyms2.o .tmp_kallsyms3.o: %.o: %.S scripts FORCE $(call if_changed_dep,as_o_S)
.tmp_kallsyms%.S: .tmp_vmlinux% $(KALLSYMS) $(call cmd,kallsyms)
# .tmp_vmlinux1 must be complete except kallsyms, so update vmlinux version .tmp_vmlinux1: $(vmlinux-lds) $(vmlinux-all) FORCE $(call if_changed_rule,ksym_ld)
.tmp_vmlinux2: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms1.o FORCE $(call if_changed,vmlinux__)
.tmp_vmlinux3: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms2.o FORCE $(call if_changed,vmlinux__)
# Needs to visit scripts/ before $(KALLSYMS) can be used. $(KALLSYMS): scripts ;
# Generate some data for debugging strange kallsyms problems debug_kallsyms: .tmp_map$(last_kallsyms) .tmp_map%: .tmp_vmlinux% FORCE
($(OBJDUMP) -h $< | $(AWK) '/^ +[0-9]/{print $$4 \" 0 \" $$2}'; $(NM) $<) | sort > $@ .tmp_map3: .tmp_map2 .tmp_map2: .tmp_map1
endif # ifdef CONFIG_KALLSYMS
# Do modpost on a prelinked vmlinux. The finally linked vmlinux has # relevant sections renamed as per the linker script. quiet_cmd_vmlinux-modpost = LD $@
cmd_vmlinux-modpost = $(LD) $(LDFLAGS) -r -o $@ / $(vmlinux-init) --start-group $(vmlinux-main) --end-group / $(filter-out $(vmlinux-init) $(vmlinux-main) FORCE ,$^) define rule_vmlinux-modpost: #定义命令包 +$(call cmd,vmlinux-modpost)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@
$(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmd endef
#================================================== #================================================== #vmlinux的依赖目标集,开始真正的做主目录下的映像文件 # vmlinux image - including updated kernel symbols
vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCE ifdef CONFIG_HEADERS_CHECK #这里主要是头检验 $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
#PHONY += headers_check 当make -f $(srctree)/Makefile headers_check执行以下命令 #headers_check: headers_install
# $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.headersinst ARCH=$(SRCARCH) obj=include HDRCHECK=1 endif
ifdef CONFIG_SAMPLES
#配置样本即调用Makefile.build 到Samples目录下make生成样本 $(Q)$(MAKE) $(build)=samples endif
$(call vmlinux-modpost)#vmlinux-modpost没有被定义,是一条多余的没有被定义的变量 $(call if_changed_rule,vmlinux__)
#在我们所以依赖目标都生成后我们开始链接!!!!!!!!!!=========== #if_changed_rule = $(if $(strip $(any-prereq) $(arg-check) ), / # @set -e; / # $(rule_$(1)))即执行rule_vmlinux__ 924line
$(Q)rm -f .old_version
# build vmlinux.o first to catch section mismatch errors early ifdef CONFIG_KALLSYMS .tmp_vmlinux1: vmlinux.o endif
#modpost-init表示除了init/下的built-in.o
modpost-init := $(filter-out init/built-in.o, $(vmlinux-init)) vmlinux.o: $(modpost-init) $(vmlinux-main) FORCE
$(call if_changed_rule,vmlinux-modpost)#这里是没有存在的,无效
# The actual objects are generated when descending, # make sure no implicit rule kicks in
$(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ; # Handle descending into subdirectories listed in $(vmlinux-dirs) # Preset locale variables to speed up the build process. Limit locale # tweaks to this spot to avoid wrong language settings when running # make menuconfig etc.
# Error messages still appears in the original language
###############真正执行动作!!!!!!#################### PHONY += $(vmlinux-dirs) #伪目标 $(vmlinux-dirs): prepare scripts $(Q)$(MAKE) $(build)=$@
#(1)build=-f scripts/Makefile.build obj= 进行实际的编
#等价于make -f scripts/Makefile.build obj=$@
#在Makefile.build中第一个真正的依赖规则是__build 大概在93行进入这里我们 #__build又依赖于各个目录下的build-in.o或者lib.a等 #$@表示vmlinux-dirs变量中的各个目标用于传给obj #vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) / # $(core-y) $(core-m) $(drivers-y) $(drivers-m) / # $(net-y) $(net-m) $(libs-y) $(libs-m))) #(2)这里的依赖目标有两个prepare:和scripts # L1180 prepare: prepare0 # L646 PHONY += scripts
# scripts: scripts_basic include/config/auto.conf
# Build the kernel release string #
# The KERNELRELEASE value built here is stored in the file # include/config/kernel.release, and is used when executing several # make targets, such as \"make install\" or \"make modules_install.\" #
# The eventual kernel release string consists of the following fields,
# shown in a hierarchical format to show how smaller parts are concatenated # to form the larger and final value, with values coming from places like # the Makefile, kernel config options, make command line options and/or # SCM tag information. #
# $(KERNELVERSION) # $(VERSION) eg, 2 # $(PATCHLEVEL) eg, 6 # $(SUBLEVEL) eg, 18 # $(EXTRAVERSION) eg, -rc6 # $(localver-full) # $(localver)
# localversion* (files without backups, containing '~') # $(CONFIG_LOCALVERSION) (from kernel config setting) # $(localver-auto) (only if CONFIG_LOCALVERSION_AUTO is set) # ./scripts/setlocalversion (SCM tag, if one exists)
# $(LOCALVERSION) (from make command line if provided) #
# Note how the final $(localver-auto) string is included *only* if the
# kernel config option CONFIG_LOCALVERSION_AUTO is selected. Also, at the # moment, only git is supported but other SCMs can edit the script # scripts/setlocalversion and add the appropriate checks as needed. pattern = \".*/localversion[^~]*\" string = $(shell cat /dev/null /
`find $(objtree) $(srctree) -maxdepth 1 -regex $(pattern) | sort -u`) localver = $(subst $(space),, $(string) /
$(patsubst \"%\
# If CONFIG_LOCALVERSION_AUTO is set scripts/setlocalversion is called # and if the SCM is know a tag from the SCM is appended. # The appended tag is determined by the SCM used. #
# Currently, only git is supported.
# Other SCMs can edit scripts/setlocalversion and add the appropriate # checks as needed.
ifdef CONFIG_LOCALVERSION_AUTO
_localver-auto = $(shell $(CONFIG_SHELL) /
$(srctree)/scripts/setlocalversion $(srctree)) localver-auto = $(LOCALVERSION)$(_localver-auto) endif
localver-full = $(localver)$(localver-auto)
# Store (new) KERNELRELASE string in include/config/kernel.release kernelrelease = $(KERNELVERSION)$(localver-full)
include/config/kernel.release: include/config/auto.conf FORCE $(Q)rm -f $@
$(Q)echo $(kernelrelease) > $@
# Things we need to do before we recursively start building the kernel # or the modules are listed in \"prepare\".
# A multi level approach is used. prepareN is processed before prepareN-1. # archprepare is used in arch Makefiles and when processed asm symlink, # version.h and scripts_basic is processed / created. # Listed in dependency order
PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3 #定义多个伪目标
# prepare3 is used to check if we are building in a separate output directory, #第三步主要检查我们是否为自定义了输出目录 # and if so do:
# 1) Check that make has not been executed in the kernel src $(srctree) # 2) Create the include2 directory, used for the second asm symlink prepare3: include/config/kernel.release ifneq ($(KBUILD_SRC),)
@echo ' Using $(srctree) as source for kernel'
$(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then / echo \" $(srctree) is not clean, please run 'make mrproper'\";/ echo \" in the '$(srctree)' directory.\";/ /bin/false; / fi;
$(Q)if [ ! -d include2 ]; then mkdir -p include2; fi;
$(Q)ln -fsn $(srctree)/include/asm-$(SRCARCH) include2/asm endif
# prepare2 creates a makefile if using a separate output directory prepare2: prepare3 outputmakefile
prepare1: prepare2 include/linux/version.h include/linux/utsrelease.h / include/asm include/config/auto.conf $(cmd_crmodverdir)
archprepare: prepare1 scripts_basic prepare0: archprepare FORCE $(Q)$(MAKE) $(build)=.
$(Q)$(MAKE) $(build)=. missing-syscalls # All the preparing.. prepare: prepare0
# Leave this as default for preprocessing vmlinux.lds.S, which is now # done in arch/$(ARCH)/kernel/Makefile
export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH) # The asm symlink changes when $(ARCH) changes. # Detect this and ask user to run make mrproper
#set -e 是设置一种shell状态即如果它执行的任何一条命令的退出码非零 #都立刻终止 include/asm: FORCE
$(Q)set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`; / if [ -L include/asm ]; then / if [ \"$$asmlink\" != \"$(SRCARCH)\" ]; then /
echo \"ERROR: the symlink $@ points to asm-$$asmlink but asm-$(SRCARCH) was expected\"; /
echo \" set ARCH or save .config and run 'make mrproper' to fix it\"; / exit 1; / fi; / else /
echo ' SYMLINK $@ -> include/asm-$(SRCARCH)'; / if [ ! -d include ]; then / mkdir -p include; / fi; /
ln -fsn asm-$(SRCARCH) $@; / fi
# Generate some files
# ---------------------------------------------------------------------------
# KERNELRELEASE can change from a few different places, meaning version.h # needs to be updated, so this check is forced on all builds uts_len := 64
define filechk_utsrelease.h
if [ `echo -n \"$(KERNELRELEASE)\" | wc -c ` -gt $(uts_len) ]; then / echo '\"$(KERNELRELEASE)\" exceeds $(uts_len) characters' >&2; / exit 1; / fi; /
(echo /#define UTS_RELEASE /\"$(KERNELRELEASE)/\";) endef
define filechk_version.h
(echo /#define LINUX_VERSION_CODE $(shell / expr $(VERSION) Kbuild))) PHONY += headers_install_all
headers_install_all: include/linux/version.h scripts_basic FORCE $(Q)$(MAKE) $(build)=scripts scripts/unifdef $(Q)for arch in $(HDRARCHES); do /
$(MAKE) ARCH=$$arch -f $(srctree)/scripts/Makefile.headersinst obj=include BIASMDIR=-bi-$$arch ;/ done
PHONY += headers_install
headers_install: include/linux/version.h scripts_basic FORCE @if [ ! -r $(srctree)/include/asm-$(SRCARCH)/Kbuild ]; then /
echo '*** Error: Headers not exportable for this architecture ($(SRCARCH))'; / exit 1 ; fi
$(Q)$(MAKE) $(build)=scripts scripts/unifdef
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.headersinst ARCH=$(SRCARCH) obj=include PHONY += headers_check_all headers_check_all: headers_install_all $(Q)for arch in $(HDRARCHES); do /
$(MAKE) ARCH=$$arch -f $(srctree)/scripts/Makefile.headersinst obj=include
BIASMDIR=-bi-$$arch HDRCHECK=1 ;/ done
PHONY += headers_check headers_check: headers_install
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.headersinst ARCH=$(SRCARCH) obj=include HDRCHECK=1
# --------------------------------------------------------------------------- # Modules
ifdef CONFIG_MODULES # By default, build modules as well all: modules # Build modules #
# A module can be listed more than once in obj-m resulting in # duplicate lines in modules.order files. Those are removed # using awk while concatenating to the final file. PHONY += modules
modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux)
$(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
@echo ' Building modules, stage 2.';
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
# Target to prepare building external modules PHONY += modules_prepare modules_prepare: prepare scripts # Target to install modules PHONY += modules_install
modules_install: _modinst_ _modinst_post PHONY += _modinst_ _modinst_:
@if [ -z \"`$(DEPMOD) -V 2>/dev/null | grep module-init-tools`\" ]; then / echo \"Warning: you may need to install module-init-tools\"; /
echo \"See http://www.codemonkey.org.uk/docs/post-halloween-2.6.txt\";/ sleep 1; /
fi
@rm -rf $(MODLIB)/kernel @rm -f $(MODLIB)/source @mkdir -p $(MODLIB)/kernel @ln -s $(srctree) $(MODLIB)/source
@if [ ! $(objtree) -ef $(MODLIB)/build ]; then / rm -f $(MODLIB)/build ; /
ln -s $(objtree) $(MODLIB)/build ; / fi
@cp -f $(objtree)/modules.order $(MODLIB)/ $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst # This depmod is only for convenience to give the initial
# boot a modules.dep even before / is mounted read-write. However the # boot script depmod is the master version. PHONY += _modinst_post _modinst_post: _modinst_ $(call cmd,depmod) else # CONFIG_MODULES # Modules not configured
# --------------------------------------------------------------------------- modules modules_install: FORCE @echo
@echo \"The present kernel configuration has modules disabled.\" @echo \"Type 'make config' and enable loadable module support.\" @echo \"Then build a kernel with module support enabled.\" @echo @exit 1
endif # CONFIG_MODULES ###
# Cleaning is done on three levels.
# make clean Delete most generated files # Leave enough to build external modules
# make mrproper Delete the current configuration, and all generated files # make distclean Remove editor backup files, patch leftover files and the like # Directories & files removed with 'make clean'
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