LINUX-Makefile全解析（编译体系）-基于Linux3.25内核

第一部分

第一节：参考文献

参考文献1.GNU make中文手册V3.8-徐海兵;
参考文献2.跟我一起写 Makefile--01(zz 陈皓)http://csc80.bokee.com/blog/1661375.html
参考文献3.
 
 GNU Make V3.79 Richard M. Stallman and Roland McGrath
参考文献4.
 Linux内核构建系统之1-10 巨立安科技Yihe.Chen的博客http://www.juliantec.info/julblog/yihect/linux-kernel-build-system-1
参考文献5.LINUX 编译系统hj_shen的博客  http://blog.csdn.net/hj_shen/article/details/2968630
参考文献6.linux make menuconfig 执行流程小结boyskung的博客 http://blog.csdn.net/BoySKung/article/details/3596762
参考文献7.Linux 3.0内核Makefile分析  mbtrend的博客http://blog.csdn.net/mbtrend/article/details/3016889
参考文献8.内核Kbuild 学习 emmoblin 的博客http://blog.chinaunix.net/space.php?uid=20778443&do=blog&id=103963
参考文献9.内核编译系统探秘之一 if_changed_rule  yuanliixjtu的博客http://blog.sina.com.cn/s/blog_61c81f910100phiq.html
参考文献10.linux 顶层Makefile执行的流程 搏仕的空间 http://hi.baidu.com/%B2%AB%CA%CB/blog/item/d0ca98d89f3068c38c1029e5.html原作者也可能是：耶和华的大卫http://www.360doc.com/content/11/1107/22/1317564_162638750.shtml，抱歉啊，作者看到了说声啊。

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第二节：本文的主要内容

1.编译出第一个镜像-讲述操作过程

2.Linux的编译体系概述
3.顶层Makefile的架构
4.Make %config的执行过程--讲述原理和使用方法
5.子目录的编译
6.Vmlinux的编译过程
7.内部和外部模块的编译过程
8.Uimage Zimage的编译过程
10.一个完整的例子
9.怎么添加一个自己的驱动
10顶层Makefile注释

11关键变量、表达式和语法注释

第二部分 主要内容

第一节 编译出第一个镜像

作者使用的试验环境是VMware Workstation虚拟机下安装的ubuntu-10.04.3-desktop-i386。
1.获得Linux内核源代码,比如从www.kernel.org处。

2.建一工作目录，比如在当前用户的目录下：~，mkdir linux_3.2.5,然后将获得的源代码复制到该目录下解压，
tar -jxvf linux-3.2.5.tar.bz2 解压后即在~/linux_3.2.5/linux_3.2.5/下获得了源代码树

3.这是假如直接在代码树顶层~/linux_3.2.5/linux_3.2.5/下运行make 则会报错(用户名瞎取的啊)：
guanyu@guanyu:~/linux_3.2.5/linux-3.2.5$ make
scripts/kconfig/conf --silentoldconfig Kconfig
***
*** Configuration file ".config" not found!
***
*** Please run some configurator (e.g. "make oldconfig" 


or
*** "make menuconfig" or "make xconfig").
***
make[2]: *** [silentoldconfig] Error 1
make[1]: *** [silentoldconfig] Error 2
make: *** No rule to make target 
`include/config/auto.conf', needed by 
`include/config/kernel.release'.  Stop.
guanyu@guanyu:~/linux_3.2.5/linux-3.2.5$ ^C
guanyu@guanyu:~/linux_3.2.5/linux-3.2.5$ 
意思就是说没有.config,至于为什么需要.config后文会详细解释。

4.运行make menuconfig 生产.config，不用改任何选项，第一次运行make menuconfig时，提示：

*** Unable to find the ncurses libraries or the
 *** required header files.
 *** 'make menuconfig' requires the ncurses libraries.
 *** 
 *** Install ncurses (ncurses-devel) and try again.
 *** 
make[1]: *** [scripts/kconfig/dochecklxdialog] Error 1
make: *** [menuconfig] Error 2
解决办法是用root账户登录，联网，然后运行
apt-get install libncurses5-dev  

5.退出make menuconfig 后执行make命令，

6执行make bzImage，就可以编译出一个镜像了。默认是x86的。会提示Kernel: arch/x86/boot/bzImage is ready ，其它架构的后面再说啦，先有个感性的认识还是好的。

第二节.Linux的编译体系概述

第三节 顶层Makefile的架构

   顶层的Makefile主要可分为四个部分，第一部分1-78行主要是定义一些变量、根据输入命令判断命令显示、代码的检测等，具体可见后文顶层Makefile的注释。剩下的三部分分别称为甲乙丙。如下图所示：

    甲：

   乙

丙部分1560-1566行：只有3句话，定义伪目标:
PHONY += FORCEFORCE:.PHONY: $(PHONY)

第四节 Make %config的执行过程与使用方法

第五节子目录的编译

第六节Vmlinux的编译过程

第七节内部和外部模块的编译过程

第八节Uimage Zimage的编译过程

VERSION = 3PATCHLEVEL = 2SUBLEVEL = 5EXTRAVERSION =NAME = Saber-toothed Squirrel# *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# Avoid funny character set dependenciesunexport LC_ALLLC_COLLATE=CLC_NUMERIC=Cexport LC_COLLATE LC_NUMERIC# 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 finally# 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 commandsifeq ("$(origin V)", "command line")  KBUILD_VERBOSE = $(V)endififndef KBUILD_VERBOSE  KBUILD_VERBOSE = 0endif# Call a source code checker (by default, "sparse") as part of the# C compilation.## Use 'make C=1' to enable checking of only re-compiled files.# Use 'make C=2' to enable checking of *all* source files, regardless# of whether they are re-compiled or not.## See the file "Documentation/sparse.txt" for more details, including# where to get the "sparse" utility.ifeq ("$(origin C)", "command line")  KBUILD_CHECKSRC = $(C)endififndef KBUILD_CHECKSRC  KBUILD_CHECKSRC = 0endif# Use make M=dir to specify directory of external module to build# Old syntax make ... SUBDIRS=$PWD is still supported# Setting the environment variable KBUILD_EXTMOD take precedenceifdef SUBDIRS  KBUILD_EXTMOD ?= $(SUBDIRS)endififeq ("$(origin M)", "command line")  KBUILD_EXTMOD := $(M)endif# kbuild supports saving output files in a separate directory.# To locate output files in a separate directory two syntaxes are supported.# In both cases the working directory must be the root of the kernel src.# 1) O=# Use "make O=dir/to/store/output/files/"## 2) Set KBUILD_OUTPUT# Set the environment variable KBUILD_OUTPUT to point to the directory# where the output files shall be placed.# export KBUILD_OUTPUT=dir/to/store/output/files/# make## The O= assignment takes precedence over the KBUILD_OUTPUT environment# variable.# KBUILD_SRC is set on invocation of make in OBJ directory# KBUILD_SRC is not intended to be used by the regular user (for now)ifeq ($(KBUILD_SRC),)# OK, Make called in directory where kernel src resides# Do we want to locate output files in a separate directory?ifeq ("$(origin O)", "command line")  KBUILD_OUTPUT := $(O)endififeq ("$(origin W)", "command line")  export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)endif# That's our default target when none is given on the command linePHONY := _all_all:# Cancel implicit rules on top Makefile$(CURDIR)/Makefile Makefile: ;ifneq ($(KBUILD_OUTPUT),)# Invoke a second make in the output directory, passing relevant variables# check that the output directory actually existssaved-output := $(KBUILD_OUTPUT)KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)$(if $(KBUILD_OUTPUT),, \     $(error output directory "$(saved-output)" does not exist))PHONY += $(MAKECMDGOALS) sub-make$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make$(Q)@:sub-make: FORCE$(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \KBUILD_SRC=$(CURDIR) \KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \$(filter-out _all sub-make,$(MAKECMDGOALS))# Leave processing to above invocation of makeskip-makefile := 1endif # ifneq ($(KBUILD_OUTPUT),)endif # ifeq ($(KBUILD_SRC),)# We process the rest of the Makefile if this is the final invocation of makeifeq ($(skip-makefile),)# If building an external module we do not care about the all: rule# but instead _all depend on modulesPHONY += allifeq ($(KBUILD_EXTMOD),)_all: allelse_all: modulesendifsrctree:= $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))objtree:= $(CURDIR)src:= $(srctree)obj:= $(objtree)VPATH:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))export srctree objtree VPATH# 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.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[234].*/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 arch/* for the possibilities).# ARCH can be set during invocation of make:# make ARCH=ia64# Another way is to have ARCH set in the environment.# The default ARCH is the host where make is executed.# CROSS_COMPILE specify the prefix used for all executables used# during compilation. Only gcc and related bin-utils executables# are prefixed with $(CROSS_COMPILE).# CROSS_COMPILE can be set on the command line# make CROSS_COMPILE=ia64-linux-# Alternatively CROSS_COMPILE can be set in the environment.# A third alternative is to store a setting in .config so that plain# "make" in the configured kernel build directory always uses that.# Default value for CROSS_COMPILE is not to prefix executables# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefileexport KBUILD_BUILDHOST := $(SUBARCH)ARCH?= $(SUBARCH)CROSS_COMPILE?= $(CONFIG_CROSS_COMPILE:"%"=%)# Architecture as present in compile.hUTS_MACHINE := $(ARCH)SRCARCH := $(ARCH)# Additional ARCH settings for x86ifeq ($(ARCH),i386)        SRCARCH := x86endififeq ($(ARCH),x86_64)        SRCARCH := x86endif# Additional ARCH settings for sparcifeq ($(ARCH),sparc32)       SRCARCH := sparcendififeq ($(ARCH),sparc64)       SRCARCH := sparcendif# Additional ARCH settings for shifeq ($(ARCH),sh64)       SRCARCH := shendif# Additional ARCH settings for tileifeq ($(ARCH),tilepro)       SRCARCH := tileendififeq ($(ARCH),tilegx)       SRCARCH := tileendif# Where to locate arch specific headershdr-arch  := $(SRCARCH)ifeq ($(ARCH),m68knommu)       hdr-arch  := m68kendifKCONFIG_CONFIG?= .configexport KCONFIG_CONFIG# SHELL used by kbuildCONFIG_SHELL := $(shell if [ -x "$BASH" ]; then echo $BASH; \  else if [ -x /bin/bash ]; then echo /bin/bash; \  else echo sh; fi ; fi)HOSTCC       = gccHOSTCXX      = g++HOSTCFLAGS   = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointerHOSTCXXFLAGS = -O2# Decide whether to build built-in, modular, or both.# Normally, just do built-in.KBUILD_MODULES :=KBUILD_BUILTIN := 1#If we have only "make modules", don't compile built-in objects.#When we're building modules with modversions, we need to consider#the built-in objects during the descend as well, in order to#make sure the checksums are up to date before we record them.ifeq ($(MAKECMDGOALS),modules)  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)endif#If we have "make <whatever> modules", compile modules#in addition to whatever we do anyway.#Just "make" or "make all" shall build modules as wellifneq ($(filter all _all modules,$(MAKECMDGOALS)),)  KBUILD_MODULES := 1endififeq ($(MAKECMDGOALS),)  KBUILD_MODULES := 1endifexport KBUILD_MODULES KBUILD_BUILTINexport KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD# Beautify output# ---------------------------------------------------------------------------## 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 $@ {1}lt;## If $(quiet) is empty, the whole command will be printed.# If it is set to "quiet_", only the short version will be printed. # If it is set to "silent_", nothing will be printed at all, since# the variable $(silent_cmd_cc_o_c) doesn't exist.## A simple variant is to prefix commands with $(Q) - that's useful# for commands that shall be hidden in non-verbose mode.##$(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)  quiet =  Q =else  quiet=quiet_  Q = @endif# If the user is running make -s (silent mode), suppress echoing of# commandsifneq ($(findstring s,$(MAKEFLAGS)),)  quiet=silent_endifexport quiet Q KBUILD_VERBOSE# Look for make include files relative to root of kernel srcMAKEFLAGS += --include-dir=$(srctree)# We need some generic definitions (do not try to remake the file).$(srctree)/scripts/Kbuild.include: ;include $(srctree)/scripts/Kbuild.include# Make variables (CC, etc...)AS= $(CROSS_COMPILE)asLD= $(CROSS_COMPILE)ldCC= $(CROSS_COMPILE)gccCPP= $(CC) -EAR= $(CROSS_COMPILE)arNM= $(CROSS_COMPILE)nmSTRIP= $(CROSS_COMPILE)stripOBJCOPY= $(CROSS_COMPILE)objcopyOBJDUMP= $(CROSS_COMPILE)objdumpAWK= awkGENKSYMS= scripts/genksyms/genksymsINSTALLKERNEL  := installkernelDEPMOD= /sbin/depmodKALLSYMS= scripts/kallsymsPERL= perlCHECK= sparseCHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \  -Wbitwise -Wno-return-void $(CF)CFLAGS_MODULE   =AFLAGS_MODULE   =LDFLAGS_MODULE  =CFLAGS_KERNEL=AFLAGS_KERNEL=CFLAGS_GCOV= -fprofile-arcs -ftest-coverage# Use LINUXINCLUDE when you must reference the include/ directory.# Needed to be compatible with the O= optionLINUXINCLUDE    := -I$(srctree)/arch/$(hdr-arch)/include \                   -Iarch/$(hdr-arch)/include/generated -Iinclude \                   $(if $(KBUILD_SRC), -I$(srctree)/include) \                   -include $(srctree)/include/linux/kconfig.hKBUILD_CPPFLAGS := -D__KERNEL__KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \   -fno-strict-aliasing -fno-common \   -Werror-implicit-function-declaration \   -Wno-format-security \   -fno-delete-null-pointer-checksKBUILD_AFLAGS_KERNEL :=KBUILD_CFLAGS_KERNEL :=KBUILD_AFLAGS   := -D__ASSEMBLY__KBUILD_AFLAGS_MODULE  := -DMODULEKBUILD_CFLAGS_MODULE  := -DMODULEKBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds# Read KERNELRELEASE from include/config/kernel.release (if it exists)KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSIONexport ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CCexport CPP AR NM STRIP OBJCOPY OBJDUMPexport MAKE AWK GENKSYMS INSTALLKERNEL PERL UTS_MACHINEexport HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGSexport KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGSexport KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOVexport KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULEexport KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULEexport KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNELexport KBUILD_ARFLAGS# 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 ... statementsRCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS -o -name .pc -o -name .hg -o -name .git \) -prune -oexport 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/PHONY += scripts_basicscripts_basic:$(Q)$(MAKE) $(build)=scripts/basic$(Q)rm -f .tmp_quiet_recordmcount# 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 ($(KBUILD_SRC),)$(Q)ln -fsn $(srctree) source$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \    $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)endif# Support for using generic headers in asm-genericPHONY += asm-genericasm-generic:$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \            obj=arch/$(SRCARCH)/include/generated/asm# 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).no-dot-config-targets := clean mrproper distclean \ cscope gtags TAGS tags help %docs check% coccicheck \ include/linux/version.h headers_% \ kernelversion %src-pkgconfig-targets := 0mixed-targets  := 0dot-config     := 1ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)dot-config := 0endifendififeq ($(KBUILD_EXTMOD),)        ifneq ($(filter config %config,$(MAKECMDGOALS)),)                config-targets := 1                ifneq ($(filter-out config %config,$(MAKECMDGOALS)),)                        mixed-targets := 1                endif        endifendififeq ($(mixed-targets),1)# ===========================================================================# We're called with mixed targets (*config and build targets).# Handle them one by one.%:: FORCE$(Q)$(MAKE) -C $(srctree) KBUILD_SRC= $@elseifeq ($(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)/Makefileexport KBUILD_DEFCONFIG KBUILD_KCONFIGconfig: scripts_basic outputmakefile FORCE$(Q)mkdir -p include/linux include/config$(Q)$(MAKE) $(build)=scripts/kconfig $@%config: scripts_basic outputmakefile FORCE$(Q)mkdir -p include/linux include/config$(Q)$(MAKE) $(build)=scripts/kconfig $@else# ===========================================================================# Build targets only - this includes vmlinux, arch specific targets, clean# targets and others. In general all targets except *config targets.ifeq ($(KBUILD_EXTMOD),)# Additional helpers built in scripts/# Carefully list dependencies so we do not try to build scripts twice# in parallelPHONY += scriptsscripts: scripts_basic include/config/auto.conf include/config/tristate.conf$(Q)$(MAKE) $(build)=$(@)# Objects we will link into vmlinux / subdirs we need to visitinit-y:= init/drivers-y:= drivers/ sound/ firmware/net-y:= net/libs-y:= lib/core-y:= usr/endif # KBUILD_EXTMODifeq ($(dot-config),1)# Read in config-include include/config/auto.confifeq ($(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 filesinclude/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd$(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfigelse# external modules needs include/generated/autoconf.h and include/config/auto.conf# but do not care if they are up-to-date. Use auto.conf to trigger the testPHONY += include/config/auto.confinclude/config/auto.conf:$(Q)test -e include/generated/autoconf.h -a -e $@ || (\echo;\echo "  ERROR: Kernel configuration is invalid.";\echo "         include/generated/autoconf.h or $@ are missing.";\echo "         Run 'make oldconfig && make prepare' on kernel src to fix it.";\echo;\/bin/false)endif # KBUILD_EXTMODelse# Dummy target needed, because used as prerequisiteinclude/config/auto.conf: ;endif # $(dot-config)# 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 to vmlinux, but the arch makefile usually adds further targetsall: vmlinuxifdef CONFIG_CC_OPTIMIZE_FOR_SIZEKBUILD_CFLAGS+= -OselseKBUILD_CFLAGS+= -O2endifinclude $(srctree)/arch/$(SRCARCH)/Makefileifneq ($(CONFIG_FRAME_WARN),0)KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})endif# Force gcc to behave correct even for buggy distributionsifndef CONFIG_CC_STACKPROTECTORKBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)endif# This warning generated too much noise in a regular build.# Use make W=1 to enable this warning (see scripts/Makefile.build)KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)ifdef CONFIG_FRAME_POINTERKBUILD_CFLAGS+= -fno-omit-frame-pointer -fno-optimize-sibling-callselse# Some targets (ARM with Thumb2, for example), can't be built with frame# pointers.  For those, we don't have FUNCTION_TRACER automatically# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is# incompatible with -fomit-frame-pointer with current GCC, so we don't use# -fomit-frame-pointer with FUNCTION_TRACER.ifndef CONFIG_FUNCTION_TRACERKBUILD_CFLAGS+= -fomit-frame-pointerendifendififdef CONFIG_DEBUG_INFOKBUILD_CFLAGS+= -gKBUILD_AFLAGS+= -gdwarf-2endififdef CONFIG_DEBUG_INFO_REDUCEDKBUILD_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly)endififdef CONFIG_FUNCTION_TRACERKBUILD_CFLAGS+= -pgifdef CONFIG_DYNAMIC_FTRACEifdef CONFIG_HAVE_C_RECORDMCOUNTBUILD_C_RECORDMCOUNT := yexport BUILD_C_RECORDMCOUNTendifendifendif# We trigger additional mismatches with less inliningifdef CONFIG_DEBUG_SECTION_MISMATCHKBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)endif# arch Makefile may override CC so keep this after arch Makefile is includedNOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)CHECKFLAGS     += $(NOSTDINC_FLAGS)# warn about C99 declaration after statementKBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)# disable pointer signed / unsigned warnings in gcc 4.0KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)# disable invalid "can't wrap" optimizations for signed / pointersKBUILD_CFLAGS+= $(call cc-option,-fno-strict-overflow)# conserve stack if availableKBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)# use the deterministic mode of AR if availableKBUILD_ARFLAGS := $(call ar-option,D)# check for 'asm goto'ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTOendif# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments# But warn user when we do sowarn-assign = \$(warning "WARNING: Appending $K$(1) ($(K$(1))) from $(origin K$(1)) to kernel $$(1)")ifneq ($(KCPPFLAGS),)        $(call warn-assign,CPPFLAGS)        KBUILD_CPPFLAGS += $(KCPPFLAGS)endififneq ($(KAFLAGS),)        $(call warn-assign,AFLAGS)        KBUILD_AFLAGS += $(KAFLAGS)endififneq ($(KCFLAGS),)        $(call warn-assign,CFLAGS)        KBUILD_CFLAGS += $(KCFLAGS)endif# Use --build-id when available.LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\      $(call cc-ldoption, -Wl$(comma)--build-id,))KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)ifeq ($(CONFIG_STRIP_ASM_SYMS),y)LDFLAGS_vmlinux+= $(call ld-option, -X,)endif# Default kernel image to build when no specific target is given.# KBUILD_IMAGE may be overruled on the command line or# set in the environment# Also any assignments in arch/$(ARCH)/Makefile take precedence over# this default valueexport 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 valuesexportINSTALL_PATH ?= /boot## 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 value will be used as the options to the strip command.ifdef INSTALL_MOD_STRIPifeq ($(INSTALL_MOD_STRIP),1)mod_strip_cmd = $(STRIP) --strip-debugelsemod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)endif # INSTALL_MOD_STRIP=1elsemod_strip_cmd = trueendif # INSTALL_MOD_STRIPexport mod_strip_cmdifeq ($(KBUILD_EXTMOD),)core-y+= kernel/ mm/ fs/ ipc/ security/ crypto/ block/vmlinux-dirs:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \     $(net-y) $(net-m) $(libs-y) $(libs-m)))vmlinux-alldirs:= $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \     $(init-n) $(init-) \     $(core-n) $(core-) $(drivers-n) $(drivers-) \     $(net-n)  $(net-)  $(libs-n)    $(libs-))))init-y:= $(patsubst %/, %/built-in.o, $(init-y))core-y:= $(patsubst %/, %/built-in.o, $(core-y))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 symbolsvmlinux-init := $(head-y) $(init-y)vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y)vmlinux-all  := $(vmlinux-init) $(vmlinux-main)vmlinux-lds  := arch/$(SRCARCH)/kernel/vmlinux.ldsexport KBUILD_VMLINUX_OBJS := $(vmlinux-all)# Rule to link vmlinux - also used during CONFIG_KALLSYMS# May be overridden by arch/$(ARCH)/Makefilequiet_cmd_vmlinux__ ?= LD      $@      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 versionquiet_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.mapquiet_cmd_sysmap = SYSMAP      cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap# Link of vmlinux# If CONFIG_KALLSYMS is set .version is already updated# Generate System.map and verify that the content is consistent# Use + in front of the vmlinux_version rule to silent warning with make -j2# First command is ':' to allow us to use + in front of the ruledefine rule_vmlinux__:$(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))$(call cmd,vmlinux__)$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd$(Q)$(if $($(quiet)cmd_sysmap),                                      \  echo '  $($(quiet)cmd_sysmap)  System.map' &&)                     \$(cmd_sysmap) $@ System.map;                                         \if [ $? -ne 0 ]; then                                               \rm -f $@;                                                    \/bin/false;                                                  \fi;$(verify_kallsyms)endefifdef CONFIG_KALLSYMS# Generate section listing all symbols and add it into vmlinux $(kallsyms.o)# It's a three stage process:# o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is#   empty#   Running kallsyms on that gives us .tmp_kallsyms1.o with#   the right size - vmlinux version (uname -v) is updated during this step# o .tmp_vmlinux2 now has a __kallsyms section of the right size,#   but due to the added section, some addresses have shifted.#   From here, we generate a correct .tmp_kallsyms2.o# o The correct .tmp_kallsyms2.o is linked into the final vmlinux.# o Verify that the System.map from vmlinux matches the map from#   .tmp_vmlinux2, just in case we did not generate kallsyms correctly.# o If 'make KALLSYMS_EXTRA_PASS=1" was used, do an extra pass using#   .tmp_vmlinux3 and .tmp_kallsyms3.o.  This is only meant as a#   temporary bypass to allow the kernel to be built while the#   maintainers work out what went wrong with kallsyms.last_kallsyms := 2ifdef KALLSYMS_EXTRA_PASSifneq ($(KALLSYMS_EXTRA_PASS),0)last_kallsyms := 3endifendifkallsyms.o := .tmp_kallsyms$(last_kallsyms).odefine verify_kallsyms$(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 This is a bug - please report about it;                \ echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround;      \ 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 rulecmd_ksym_ld = $(cmd_vmlinux__)define rule_ksym_ld: +$(call cmd,vmlinux_version)$(call cmd,vmlinux__)$(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmdendef# Generate .S file with all kernel symbolsquiet_cmd_kallsyms = KSYM    $@      cmd_kallsyms = $(NM) -n {1}lt; | $(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 problemsdebug_kallsyms: .tmp_map$(last_kallsyms).tmp_map%: .tmp_vmlinux% FORCE($(OBJDUMP) -h {1}lt; | $(AWK) '/^ +[0-9]/{print $4 " 0 " $2}'; $(NM) {1}lt;) | sort > $@.tmp_map3: .tmp_map2.tmp_map2: .tmp_map1endif # 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:+$(call cmd,vmlinux-modpost)$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@$(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmdendef# vmlinux image - including updated kernel symbolsvmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCEifdef CONFIG_HEADERS_CHECK$(Q)$(MAKE) -f $(srctree)/Makefile headers_checkendififdef CONFIG_SAMPLES$(Q)$(MAKE) $(build)=samplesendififdef CONFIG_BUILD_DOCSRC$(Q)$(MAKE) $(build)=Documentationendif$(call vmlinux-modpost)$(call if_changed_rule,vmlinux__)$(Q)rm -f .old_version# build vmlinux.o first to catch section mismatch errors earlyifdef CONFIG_KALLSYMS.tmp_vmlinux1: vmlinux.oendifmodpost-init := $(filter-out init/built-in.o, $(vmlinux-init))vmlinux.o: $(modpost-init) $(vmlinux-main) FORCE$(call if_changed_rule,vmlinux-modpost)# 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 languagePHONY += $(vmlinux-dirs)$(vmlinux-dirs): prepare scripts$(Q)$(MAKE) $(build)=$@# Store (new) KERNELRELASE string in include/config/kernel.releaseinclude/config/kernel.release: include/config/auto.conf FORCE$(Q)rm -f $@$(Q)echo "$(KERNELVERSION)$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))" > $@# 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 orderPHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3# prepare3 is used to check if we are building in a separate output directory,# and if so do:# 1) Check that make has not been executed in the kernel src $(srctree)prepare3: include/config/kernel.releaseifneq ($(KBUILD_SRC),)@$(kecho) '  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;endif# prepare2 creates a makefile if using a separate output directoryprepare2: prepare3 outputmakefile asm-genericprepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \                   include/config/auto.conf$(cmd_crmodverdir)archprepare: prepare1 scripts_basicprepare0: archprepare FORCE$(Q)$(MAKE) $(build)=.# All the preparing..prepare: prepare0# Generate some files# ---------------------------------------------------------------------------# KERNELRELEASE can change from a few different places, meaning version.h# needs to be updated, so this check is forced on all buildsuts_len := 64define filechk_utsrelease.hif [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \  exit 1;                                                         \fi;                                                               \(echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)endefdefine filechk_version.h(echo \#define LINUX_VERSION_CODE $(shell                             \expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL));    \echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)endefinclude/linux/version.h: $(srctree)/Makefile FORCE$(call filechk,version.h)include/generated/utsrelease.h: include/config/kernel.release FORCE$(call filechk,utsrelease.h)PHONY += headerdepheaderdep:$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \$(srctree)/scripts/headerdep.pl -I$(srctree)/include# ---------------------------------------------------------------------------PHONY += depend depdepend dep:@echo '*** Warning: make $@ is unnecessary now.'# ---------------------------------------------------------------------------# Firmware installINSTALL_FW_PATH=$(INSTALL_MOD_PATH)/lib/firmwareexport INSTALL_FW_PATHPHONY += firmware_installfirmware_install: FORCE@mkdir -p $(objtree)/firmware$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_install# ---------------------------------------------------------------------------# Kernel headers#Default location for installed headersexport INSTALL_HDR_PATH = $(objtree)/usrhdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj# If we do an all arch process set dst to asm-$(hdr-arch)hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)PHONY += __headers__headers: include/linux/version.h scripts_basic asm-generic FORCE$(Q)$(MAKE) $(build)=scripts build_unifdefPHONY += headers_install_allheaders_install_all:$(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh installPHONY += headers_installheaders_install: __headers$(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/asm/Kbuild),, \$(error Headers not exportable for the $(SRCARCH) architecture))$(Q)$(MAKE) $(hdr-inst)=include$(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/asm $(hdr-dst)PHONY += headers_check_allheaders_check_all: headers_install_all$(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh checkPHONY += headers_checkheaders_check: headers_install$(Q)$(MAKE) $(hdr-inst)=include HDRCHECK=1$(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/asm $(hdr-dst) HDRCHECK=1# ---------------------------------------------------------------------------# Modulesifdef CONFIG_MODULES# By default, build modules as wellall: 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 += modulesmodules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin$(Q)$(AWK) '!x[$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order@$(kecho) '  Building modules, stage 2.';$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modbuildmodules.builtin: $(vmlinux-dirs:%=%/modules.builtin)$(Q)$(AWK) '!x[$0]++' $^ > $(objtree)/modules.builtin%/modules.builtin: include/config/auto.conf$(Q)$(MAKE) $(modbuiltin)=$*# Target to prepare building external modulesPHONY += modules_preparemodules_prepare: prepare scripts# Target to install modulesPHONY += modules_installmodules_install: _modinst_ _modinst_postPHONY += _modinst__modinst_:@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)/@cp -f $(objtree)/modules.builtin $(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_$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_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 1endif # 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'CLEAN_DIRS  += $(MODVERDIR)CLEAN_FILES +=vmlinux System.map \                .tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map# Directories & files removed with 'make mrproper'MRPROPER_DIRS  += include/config usr/include include/generated          \                  arch/*/include/generatedMRPROPER_FILES += .config .config.old .version .old_version             \                  include/linux/version.h                               \  Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS# clean - Delete most, but leave enough to build external modules#clean: rm-dirs  := $(CLEAN_DIRS)clean: rm-files := $(CLEAN_FILES)clean-dirs      := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation)PHONY += $(clean-dirs) clean archclean$(clean-dirs):$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)clean: archclean# mrproper - Delete all generated files, including .config#mrproper: rm-dirs  := $(wildcard $(MRPROPER_DIRS))mrproper: rm-files := $(wildcard $(MRPROPER_FILES))mrproper-dirs      := $(addprefix _mrproper_,Documentation/DocBook scripts)PHONY += $(mrproper-dirs) mrproper archmrproper$(mrproper-dirs):$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)mrproper: clean archmrproper $(mrproper-dirs)$(call cmd,rmdirs)$(call cmd,rmfiles)# distclean#PHONY += distcleandistclean: mrproper@find $(srctree) $(RCS_FIND_IGNORE) \\( -name '*.orig' -o -name '*.rej' -o -name '*~' \-o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \-o -name '.*.rej' \-o -name '*%' -o -name '.*.cmd' -o -name 'core' \) \-type f -print | xargs rm -f# Packaging of the kernel to various formats# ---------------------------------------------------------------------------# rpm target kept for backward compatibilitypackage-dir:= $(srctree)/scripts/package%src-pkg: FORCE$(Q)$(MAKE) $(build)=$(package-dir) $@%pkg: include/config/kernel.release FORCE$(Q)$(MAKE) $(build)=$(package-dir) $@rpm: include/config/kernel.release FORCE$(Q)$(MAKE) $(build)=$(package-dir) $@# Brief documentation of the typical targets used# ---------------------------------------------------------------------------boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)boards := $(notdir $(boards))board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))board-dirs := $(sort $(notdir $(board-dirs:/=)))help:@echo  'Cleaning targets:'@echo  '  clean  - Remove most generated files but keep the config and'@echo  '                    enough build support to build external modules'@echo  '  mrproper  - Remove all generated files + config + various backup files'@echo  '  distclean  - mrproper + remove editor backup and patch files'@echo  ''@echo  'Configuration targets:'@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help@echo  ''@echo  'Other generic targets:'@echo  '  all  - Build all targets marked with [*]'@echo  '* vmlinux  - Build the bare kernel'@echo  '* modules  - Build all modules'@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'@echo  '  firmware_install- Install all firmware to INSTALL_FW_PATH'@echo  '                    (default: $(INSTALL_MOD_PATH)/lib/firmware)'@echo  '  dir/            - Build all files in dir and below'@echo  '  dir/file.[oisS] - Build specified target only'@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'@echo  '                    (requires a recent binutils and recent build (System.map))'@echo  '  dir/file.ko     - Build module including final link'@echo  '  modules_prepare - Set up for building external modules'@echo  '  tags/TAGS  - Generate tags file for editors'@echo  '  cscope  - Generate cscope index'@echo  '  gtags           - Generate GNU GLOBAL index'@echo  '  kernelrelease  - Output the release version string'@echo  '  kernelversion  - Output the version stored in Makefile'@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \ echo  '                    (default: $(INSTALL_HDR_PATH))'; \ echo  ''@echo  'Static analysers'@echo  '  checkstack      - Generate a list of stack hogs'@echo  '  namespacecheck  - Name space analysis on compiled kernel'@echo  '  versioncheck    - Sanity check on version.h usage'@echo  '  includecheck    - Check for duplicate included header files'@echo  '  export_report   - List the usages of all exported symbols'@echo  '  headers_check   - Sanity check on exported headers'@echo  '  headerdep       - Detect inclusion cycles in headers'@$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help@echo  ''@echo  'Kernel packaging:'@$(MAKE) $(build)=$(package-dir) help@echo  ''@echo  'Documentation targets:'@$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp@echo  ''@echo  'Architecture specific targets ($(SRCARCH)):'@$(if $(archhelp),$(archhelp),\echo '  No architecture specific help defined for $(SRCARCH)')@echo  ''@$(if $(boards), \$(foreach b, $(boards), \printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \echo '')@$(if $(board-dirs), \$(foreach b, $(board-dirs), \printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \printf "  %-16s - Show all of the above\\n" help-boards; \echo '')@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'@echo  '  make C=1   [targets] Check all c source with $CHECK (sparse by default)'@echo  '  make C=2   [targets] Force check of all c source with $CHECK'@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'@echo  '  make W=n   [targets] Enable extra gcc checks, n=1,2,3 where'@echo  '1: warnings which may be relevant and do not occur too often'@echo  '2: warnings which occur quite often but may still be relevant'@echo  '3: more obscure warnings, can most likely be ignored'@echo  'Multiple levels can be combined with W=12 or W=123'@echo  ''@echo  'Execute "make" or "make all" to build all targets marked with [*] '@echo  'For further info see the ./README file'help-board-dirs := $(addprefix help-,$(board-dirs))help-boards: $(help-board-dirs)boards-per-dir = $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig))$(help-board-dirs): help-%:@echo  'Architecture specific targets ($(SRCARCH) $*):'@$(if $(boards-per-dir), \$(foreach b, $(boards-per-dir), \printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \echo '')# Documentation targets# ---------------------------------------------------------------------------%docs: scripts_basic FORCE$(Q)$(MAKE) $(build)=scripts build_docproc$(Q)$(MAKE) $(build)=Documentation/DocBook $@else # KBUILD_EXTMOD#### External module support.# When building external modules the kernel used as basis is considered# read-only, and no consistency checks are made and the make# system is not used on the basis kernel. If updates are required# in the basis kernel ordinary make commands (without M=...) must# be used.## The following are the only valid targets when building external# modules.# make M=dir clean     Delete all automatically generated files# make M=dir modules   Make all modules in specified dir# make M=dir       Same as 'make M=dir modules'# make M=dir modules_install#                      Install the modules built in the module directory#                      Assumes install directory is already created# We are always building modulesKBUILD_MODULES := 1PHONY += crmodverdircrmodverdir:$(cmd_crmodverdir)PHONY += $(objtree)/Module.symvers$(objtree)/Module.symvers:@test -e $(objtree)/Module.symvers || ( \echo; \echo "  WARNING: Symbol version dump $(objtree)/Module.symvers"; \echo "           is missing; modules will have no dependencies and modversions."; \echo )module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))PHONY += $(module-dirs) modules$(module-dirs): crmodverdir $(objtree)/Module.symvers$(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)modules: $(module-dirs)@$(kecho) '  Building modules, stage 2.';$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpostPHONY += modules_installmodules_install: _emodinst_ _emodinst_postinstall-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)PHONY += _emodinst__emodinst_:$(Q)mkdir -p $(MODLIB)/$(install-dir)$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinstPHONY += _emodinst_post_emodinst_post: _emodinst_$(call cmd,depmod)clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))PHONY += $(clean-dirs) clean$(clean-dirs):$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)clean:rm-dirs := $(MODVERDIR)clean: rm-files := $(KBUILD_EXTMOD)/Module.symvershelp:@echo  '  Building external modules.'@echo  '  Syntax: make -C path/to/kernel/src M=$PWD target'@echo  ''@echo  '  modules         - default target, build the module(s)'@echo  '  modules_install - install the module'@echo  '  clean           - remove generated files in module directory only'@echo  ''# Dummies...PHONY += prepare scriptsprepare: ;scripts: ;endif # KBUILD_EXTMODclean: $(clean-dirs)$(call cmd,rmdirs)$(call cmd,rmfiles)@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \\( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \-o -name '*.symtypes' -o -name 'modules.order' \-o -name modules.builtin -o -name '.tmp_*.o.*' \-o -name '*.gcno' \) -type f -print | xargs rm -f# Generate tags for editors# ---------------------------------------------------------------------------quiet_cmd_tags = GEN     $@      cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@tags TAGS cscope gtags: FORCE$(call cmd,tags)# Scripts to check various things for consistency# ---------------------------------------------------------------------------PHONY += includecheck versioncheck coccicheck namespacecheck export_reportincludecheck:find $(srctree)/* $(RCS_FIND_IGNORE) \-name '*.[hcS]' -type f -print | sort \| xargs $(PERL) -w $(srctree)/scripts/checkincludes.plversioncheck:find $(srctree)/* $(RCS_FIND_IGNORE) \-name '*.[hcS]' -type f -print | sort \| xargs $(PERL) -w $(srctree)/scripts/checkversion.plcoccicheck:$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@namespacecheck:$(PERL) $(srctree)/scripts/namespace.plexport_report:$(PERL) $(srctree)/scripts/export_report.plendif #ifeq ($(config-targets),1)endif #ifeq ($(mixed-targets),1)PHONY += checkstack kernelrelease kernelversion# UML needs a little special treatment here.  It wants to use the host# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone# else wants $(ARCH), including people doing cross-builds, which means# that $(SUBARCH) doesn't work here.ifeq ($(ARCH), um)CHECKSTACK_ARCH := $(SUBARCH)elseCHECKSTACK_ARCH := $(ARCH)endifcheckstack:$(OBJDUMP) -d vmlinux $(find . -name '*.ko') | \$(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)kernelrelease:@echo "$(KERNELVERSION)$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"kernelversion:@echo $(KERNELVERSION)# Single targets# ---------------------------------------------------------------------------# Single targets are compatible with:# - build with mixed source and output# - build with separate output dir 'make O=...'# - external modules##  target-dir => where to store outputfile#  build-dir  => directory in kernel source tree to useifeq ($(KBUILD_EXTMOD),)        build-dir  = $(patsubst %/,%,$(dir $@))        target-dir = $(dir $@)else        zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))        build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))        target-dir = $(if $(KBUILD_EXTMOD),$(dir {1}lt;),$(dir $@))endif%.s: %.c prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.i: %.c prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.o: %.c prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.lst: %.c prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.s: %.S prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.o: %.S prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)%.symtypes: %.c prepare scripts FORCE$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)# Modules/: prepare scripts FORCE$(cmd_crmodverdir)$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \$(build)=$(build-dir)%/: prepare scripts FORCE$(cmd_crmodverdir)$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \$(build)=$(build-dir)%.ko: prepare scripts FORCE$(cmd_crmodverdir)$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \$(build)=$(build-dir) $(@:.ko=.o)$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost# FIXME Should go into a make.lib or something # ===========================================================================quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))      cmd_rmdirs = rm -rf $(rm-dirs)quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))      cmd_rmfiles = rm -f $(rm-files)# Run depmod only if we have System.map and depmod is executablequiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \                   $(KERNELRELEASE)# Create temporary dir for module support files# clean it up only when building all modulescmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \                  $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \  $(KBUILD_AFLAGS_KERNEL)                              \  $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(KBUILD_CPPFLAGS) \  $(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)quiet_cmd_as_o_S = AS      $@cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ {1}lt;# read all saved command linestargets := $(wildcard $(sort $(targets)))cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))ifneq ($(cmd_files),)  $(cmd_files): ;# Do not try to update included dependency files  include $(cmd_files)endif# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=dir# Usage:# $(Q)$(MAKE) $(clean)=dirclean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean objendif# skip-makefilePHONY += FORCEFORCE:# Declare the contents of the .PHONY variable as phony.  We keep that# information in a variable so we can use it in if_changed and friends..PHONY: $(PHONY)

第九节一个完整的例子

第十节怎么添加一个自己的驱动

第十一节顶层Makefile注释

第十二节关键变量、表达式和语法注释