uboot学习之Makefile之配置过程
uboot-1.1.6源码分析
分析配置过程:
(1)安装交叉编译工具arm-linux-gcc,否则编译报错
(2)执行make canmb_config
@$(MKCONFIG) -a canmb ppc mpc5xxx canmb
(1) MKCONFIG := $(SRCTREE)/mkconfig
(2)
(3)
$(@:_config=) @代表的是target smdk2410_config,
那么$(@:_config=)就是将smdk2410_config中的_config替换为空!得到smdk2410;
$(@:_config=)什么意思?
(4)
cmi_mpc5xx_config: unconfig
@$(MKCONFIG) $(@:_config=) ppc mpc5xx cmi
<==> mkconfig cmi_mpc5xx ppc mpc5xx cmi
canmb_config: unconfig
@$(MKCONFIG) -a canmb ppc mpc5xxx canmb
<==> mkconfig canmb ppc mpc5xxx canmb
分析mkconfig(mkconfig cmi_mpc5xx ppc mpc5xx cmi)
(1)
分析传入的命令
mkconfig cmi_mpc5xx ppc mpc5xx cmi
mkconfig canmb ppc mpc5xxx canmb
$0 $1 $2 $3 $4
while [ $# -gt 0 ] ; do
case "$1" in
--) shift ; break ;;
-a) shift ; APPEND=yes ;;
-n) shift ; BOARD_NAME="${1%%_config}" ; shift ;;
*) break ;;
esac
done
(2)
[ "${BOARD_NAME}" ] || BOARD_NAME="$1"
BOARD_NAME=cmi_mpc5xx
(3) 小于4个退出,大于9个退出
[ $# -lt 4 ] && exit 1
[ $# -gt 9 ] && exit 1
(4)
if [ "$SRCTREE" != "$OBJTREE" ] ; then
mkdir -p ${OBJTREE}/include
mkdir -p ${OBJTREE}/include2
cd ${OBJTREE}/include2
rm -f asm
ln -s ${SRCTREE}/include/asm-$2 asm
LNPREFIX="../../include2/asm/"
cd ../include
rm -rf asm-$2
rm -f asm
mkdir asm-$2
ln -s asm-$2 asm
查找Makefile文件
OBJTREE := $(if $(BUILD_DIR),$(BUILD_DIR),$(CURDIR))
SRCTREE := $(CURDIR)
TOPDIR := $(SRCTREE)
LNDIR := $(OBJTREE)
export TOPDIR SRCTREE OBJTREE
如果定义了BUILD_DIR,则OBJTREE就为BUILD_DIR,如果没有定义就为CURDIR。
BUILD_DIR有如下定义:
ifdef O
ifeq ("$(origin O)", "command line")
BUILD_DIR := $(O)
endif
endif
这里可以看到BUILD_DIR 没有定义,所以SRCTREE == OBJTREE
else
cd ./include
rm -f asm
ln -s asm-$2 asm
fi
ln -s asm-$2 asm <==> ln -s asm-ppc asm
意思为创建链接文件asm指向asm-arm文件夹
如果第6个参数为空
if [ -z "$6" -o "$6" = "NULL" ] ; then
ln -s ${LNPREFIX}arch-$3 asm-$2/arch
else
ln -s ${LNPREFIX}arch-$6 asm-$2/arch
fi
ln -s ${LNPREFIX}arch-$3 asm-$2/arch
==> ln -s arch-mpc5xx asm-ppc/arch
创建编译文件
echo "ARCH = $2" > config.mk
echo "CPU = $3" >> config.mk
echo "BOARD = $4" >> config.mk
#如果第5第6个参数存在则有如下内容
[ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk
[ "$6" ] && [ "$6" != "NULL" ] && echo "SOC = $6" >> config.mk
内容为:
ARCH = ppc
CPU = mpc5xx
BOARD = canmb
创建建一个文件config.h
if [ "$APPEND" = "yes" ] # Append to existing config file
then
echo >> config.h
else
> config.h # Create new config file
fi
config.h的内容
echo "/* Automatically generated - do not edit */" >>config.h
echo "#include <configs/$1.h>" >>config.h