vivi Makefile詳解

#等號定義變量，等號定義的爲遞歸變量
VERSION = 0
PATCHLEVEL = 1
SUBLEVEL = 4

#VIVIRELEASE就是0.1.4
VIVIRELEASE=$(VERSION).$(PATCHLEVEL).$(SUBLEVEL)

# :=定義常數，:=會對右邊部分立即求值
ARCH := arm

# -x file爲 對file有可執行權限，如果爲目錄，則有搜索權限 CONFIG_SHELL等於$$BASH或者/bin/bash或者sh
# $$BASH打印出一個數字跟着BASH，看不懂什麼意思，望高手指點
CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; /
    else if [ -x /bin/bash ]; then echo /bin/bash; /
    else echo sh; fi ; fi)

#TOPDIR等於當前目錄
TOPDIR    := $(shell /bin/pwd)

#
# change this to point to the Linux include directory
#
LINUX_INCLUDE_DIR    = /friendly-arm/kernel/include/


VIVIPATH           = $(TOPDIR)/include

HOSTCC          = gcc
#指定編譯的參數
HOSTCFLAGS      = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer

CROSS_COMPILE   = arm-linux-
#CROSS_COMPILE   = /opt/host/armv4l/bin/armv4l-redhat-linux-

#
# Include the make variables (CC, etc...)
#

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
MAKEFILES       = $(TOPDIR)/.config
MD5SUM        = md5sum
PERL            = perl
AWK        = awk

#導出變量，以便下層Makefile文件使用
export  VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE /
        CONFIG_SHELL TOPDIR VIVIPATH HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC /
    CPP AR NM STRIP OBJCOPY OBJDUMP MAKE MAKEFILES MD5SUM PERL AWK

all:     do-it-all

#測試當前目錄下.config文件是否存在
#$(wildcard .config)是函數
ifeq (.config,$(wildcard .config))
include .config
else
CONFIGURATION = config
do-it-all:    config
endif

#do-it-all依賴於Version vivi
do-it-all:    Version vivi

#
# standard CFLAGS
#
#包含頭文件的路徑
CPPFLAGS := -I$(VIVIPATH) -I$(LINUX_INCLUDE_DIR)
#CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes -Wno-trigraphs -O2 /
#          -fomit-frame-pointer -fno-strict-aliasing -fno-common
#2種參數
CFLAGS := $(CPPFLAGS) -Wall -Wstrict-prototypes -O2 -fPIC -fomit-frame-pointer
AFLAGS := -D__ASSEMBLY__ $(CPPFLAGS)

CORE_FILES    = init/main.o init/version.o lib/lib.o
LIBS            := lib/priv_data/priv_data.o
SUBDIRS         = drivers lib

#如果在.config文件中定義了CONFIG_SERIAL和CONFIG_MTD，最後DRIVERS：=drivers/serial/serial.o drivers/mtd/mtd.o
DRIVERS-y :=
DRIVERS-$(CONFIG_SERIAL) += drivers/serial/serial.o
DRIVERS-$(CONFIG_MTD) += drivers/mtd/mtd.o
DRIVERS := $(DRIVERS-y)

#make clean時刪除的文件
CLEAN_FILES = /
    vivi-elf /
    vivi /
    vivi.nm /
    vivi.map

#
# Location of the gcc arm libs.
#
#定義arm-linux-gcc庫的位置
ARM_GCC_LIBS    = /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3
#ARM_GCC_LIBS    = /opt/host/armv4l/lib/gcc-lib/armv4l-redhat-linux/2.95.3

#-R是arm-linux-objcopy的參數
OBJCOPYFLAGS = -R .comment -R .stab -R .stabstr

CLIBS = -L$(ARM_GCC_LIBS) -lgcc -lc
LINKFLAGS = -Tarch/vivi.lds -Bstatic

DISTCLEAN_FILES = /
    include/autoconf.h include/version.h /
    scripts/lxdialog/*.o scripts/lxdialog/lxdialog /
    .menuconfig.log /
    .config .config.old TAGS tags

#插入Makefile文件
include arch/Makefile

export  CPPFLAGS CFLAGS AFLAGS

export  DRIVERS LDFLAGS

#@只執行，後面的語句不打印出來
Version: dummy
    @rm -f include/compile.h

vivi: include/version.h $(CONFIGURATION) init/main.o init/version.o linuxsubdirs
    $(LD) -v $(LINKFLAGS) /
        $(HEAD) /
        $(CORE_FILES) /
        $(DRIVERS) /
        $(LIBS) /
        -o vivi-elf $(CLIBS)
    $(NM) -v -l vivi-elf > vivi.map
    $(OBJCOPY) -O binary -S vivi-elf vivi $(OBJCOPYFLAGS)

oldconfig:
    $(CONFIG_SHELL) scripts/Configure -d arch/config.in

config:
    $(CONFIG_SHELL) scripts/Configure arch/config.in

menuconfig: include/version.h
    $(MAKE) -C scripts/lxdialog all
    $(CONFIG_SHELL) scripts/Menuconfig arch/config.in

clean:
    find . /( -name '*.o' -o -name core -o -name ".*.flags" /) -type f -print /
    | grep -v lxdialog/ | xargs rm -f
    rm -f $(CLEAN_FILES)

distclean: clean
    rm -f $(DISTCLEAN_FILES)

#$(MAKE)=make
linuxsubdirs: $(patsubst %, _dir_%, $(SUBDIRS))

#$@工作目標的文件名
$(patsubst %, _dir_%, $(SUBDIRS)) : include/version.h
    $(MAKE) CFLAGS="$(CFLAGS) $(CFLAGS_KERNEL)" -C $(patsubst _dir_%, %, $@)

$(TOPDIR)/include/version.h: include/version.h
$(TOPDIR)/include/compile.h: include/compile.h

include/compile.h: $(CONFIGURATION) include/version.h
    @echo -n /#define UTS_VERSION /"/#$(VIVIRELEASE) > .ver
    @if [ -f .name ]; then  echo -n /-`cat .name` >> .ver; fi
    @echo ' '`date`'"' >> .ver
    @echo /#define VIVI_COMPILE_TIME /"`date +%T`/" >> .ver
    @echo /#define VIVI_COMPILE_BY /"`whoami`/" >> .ver
    @echo /#define VIVI_COMPILE_HOST /"`hostname`/" >> .ver
    @if [ -x /bin/dnsdomainname ]; then /
       echo /#define VIVI_COMPILE_DOMAIN /"`dnsdomainname`/"; /
     elif [ -x /bin/domainname ]; then /
       echo /#define VIVI_COMPILE_DOMAIN /"`domainname`/"; /
     else /
       echo /#define VIVI_COMPILE_DOMAIN ; /
     fi >> .ver
    @echo /#define VIVI_COMPILER /"`$(CC) $(CFLAGS) -v 2>&1 | tail -1`/" >> .ver
    @mv -f .ver $@

include/version.h:
    @echo /#define VIVI_RELEASE /"$(VIVIRELEASE)/" > .ver
    @echo /#define VIVI_VERSION_CODE `expr $(VERSION) //* 65536 + $(PATCHLEVEL) //* 256 + $(SUBLEVEL)` >> .ver
    @echo '#define VIVI_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))' >>.ver
    @mv -f .ver $@

init/version.o: init/version.c include/compile.h
    $(CC) $(CFLAGS) -DUTS_MACHINE='"$(ARCH)"' -c -o init/version.o init/version.c

init/main.o: init/main.c
    $(CC) $(CFLAGS) $(CFLAGS_KERNEL) $(PROFILING) -c -o $*.o $<

TAGS: dummy
    etags `find include -name '*.h'`
    find $(SUBDIRS) init -name '*.[ch]' | xargs etags -a

# Exuberant ctags works better with -I
tags: dummy
    CTAGSF=`ctags --version | grep -i exuberant >/dev/null && echo "-I __initdata,__exitdata,EXPORT_SYMBOL,EXPORT_SYMBOL_NOVERS"`; /
    ctags $$CTAGSF `find include -name '*.h'` && /
    find $(SUBDIRS) init -name '*.[ch]' | xargs ctags $$CTAGSF -a

%: ./arch/def-configs/%
    $(MAKE) distclean
    cp arch/def-configs/$* ./.config -f
    $(MAKE) oldconfig
    $(MAKE)
   

ifdef CONFIGURATION
..$(CONFIGURATION):
    @echo
    @echo "You have a bad or nonexistent" .$(CONFIGURATION) ": running 'make" $(CONFIGURATION)"'"
    @echo
    $(MAKE) $(CONFIGURATION)
    @echo
    @echo "Successful. Try re-making (ignore the error that follows)"
    @echo
    exit 1

dummy:

else

dummy:

endif

include Rules.make