u-boot 2、配置

在上一篇的u-boot移植中，修改uboot目录下的Makefile文件，增加：

mx6q_hd300_config : unconfig

@$(MKCONFIG) $(@:_config=) arm arm_cortexa8 mx6q_hd300 freescale mx6

并且调用make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- mx6q_hd300_config配置内核，那么配置过程会做那些操作呢？

1、make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- mx6q_hd300_config，实际就是执行@$(MKCONFIG) $(@:_config=) arm arm_cortexa8 mx6q_hd300 freescale mx6，根据Makefile的定义，这段话实际就是mkconfig mx6q_hd300 arm arm_cortexa8 mx6q_hd300 freescale mx6

mkconfig脚本内容如下(黄色为注释)：

$0 $1 $2 $3 $4 $5 $6

mkconfig mx6q_hd300 arm arm_cortexa8 mx6q_hd300 freescale mx6

APPEND=no # Default: Create new config file

BOARD_NAME="" # Name to print in make output

while [ $# -gt 0 ] ; do

case "$1" in

--) shift ; break ;;

-a) shift ; APPEND=yes ;;

-n) shift ; BOARD_NAME="${1%%_config}" ; shift ;;

*) break ;;

esac

done

[ "${BOARD_NAME}" ] || BOARD_NAME="$1" //BOARD_NAME=mx6q_hd300

[ $# -lt 4 ] && exit 1

[ $# -gt 6 ] && exit 1

echo "Configuring for ${BOARD_NAME} board..."

#

# Create link to architecture specific headers

#

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

else

cd ./include

rm -f asm

ln -s asm-$2 asm include/asm--->include/asm-arm

fi

rm -f asm-$2/arch

if [ -z "$6" -o "$6" = "NULL" ] ; then

ln -s ${LNPREFIX}arch-$3 asm-$2/arch

else

ln -s ${LNPREFIX}arch-$6 asm-$2/arch include/asm-arm/arch-->include/asm-arm/arch-mx6

fi

if [ "$2" = "arm" ] ; then

rm -f asm-$2/proc

ln -s ${LNPREFIX}proc-armv asm-$2/proc include/asm-arm/proc-->include/asm-arm/proc-armv

fi

#

# Create include file for Make

#

echo "ARCH = $2" > config.mk create include/config.mk,add ARCH = arm

echo "CPU = $3" >> config.mk CPU = arm_cortexa8

echo "BOARD = $4" >> config.mk
BOARD = mx6q_hd300

[ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk VENDOR = freescare

[ "$6" ] && [ "$6" != "NULL" ] && echo "SOC = $6" >> config.mk SOC = mx6

#

# Create board specific header file

#

if [ "$APPEND" = "yes" ] # Append to existing config file

then

echo >> config.h

else

> config.h
# Create new config file, include/config.h

fi

echo "/* Automatically generated - do not edit */" >>config.h

echo "#include <configs/$1.h>" >>config.h #include <configs/mx6q_hd300.h>

echo "#include <asm/config.h>" >>config.h #include <asm/config.h>

exit 0

总结：

(1)开发板的名称：BOARD_NAME

(2)创建了三个链接

作用：我的理解是不需要在u-boot的程序中，为每一个平台和board分别添加对应的头文件。例如：

#include <asm/config.h> 实际上：#include <asm-arm.h/config.h>

(3)config.mk：u-boot对应的硬件平台

(4)configs.h：

#include <configs/$1.h>

#include <asm/config.h>

如果在board目录下新建了一个开发板的目录，则在include/configs目录下也要创建一个<board_name>.h文件。u-boot没有类似于linux的可视化配置界面，要手动修改配置文件include/configs/<board_name>.h，来裁剪u-boot和设置U-boot的参数。