U-Boot--配置过程分析

arm核：arm920t    2410

uboot版本：u-boot1.1.6

通过readme可以知道配置执行make smdk2410_config命令。

顶层Makefile :

 smdk2410_config    :    unconfig
     @$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0

上面将smdk2410   arm   arm920t   smdk2410   null   s3c2x0 六个参数穿个mkconfig.下面看顶层mkconfig文件：

 #!/bin/sh -e

 # Script to create header files and links to configure
 # U-Boot for a specific board.
 #
 # Parameters:  Target  Architecture  CPU  Board [VENDOR] [SOC]
 #
 # (C) - DENX Software Engineering, Wolfgang Denk <wd@denx.de>
 #

 APPEND=no    # Default: Create new config file
 BOARD_NAME=""    # Name to print in make output

 while [ $# -gt  ] ; do          @@$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0
     case "$1" in             @因为上面的$(@:_config=)把smdk2410_config的_config替换为空，所以不存在_
     --) shift ; break ;;     @所以这个循环不动作
     -a) shift ; APPEND=yes ;;
     -n) shift ; BOARD_NAME="${1%%_config}" ; shift ;;
     *)  break ;;
     esac
 done

 [ "${BOARD_NAME}" ] || BOARD_NAME="$1"     @BOARD_NAME=smdk2410

 [ $# -lt  ] && exit
 [ $# -gt  ] && exit 

 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 ${SRCTREE}/include/asm-$ asm
     LNPREFIX="../../include2/asm/"
     cd ../include
     rm -rf asm-$
     rm -f asm
     mkdir asm-$
     ln -s asm-$ asm
 else
     cd ./include
     rm -f asm
     ln -s asm-$ asm
 fi                               @@上面是建立或者删除一些目录

 rm -f asm-$/arch                @rm -f asm-arm/arch

 if [ -z "$6" -o "$6" = "NULL" ] ; then          @$=s3c24x0  不为空  所以执行else
     ln -s ${LNPREFIX}arch-$ asm-$/arch
 else
     ln -s ${LNPREFIX}arch-$ asm-$/arch    @LNPREFIX为空 所以相当于ln -s arch-s3c24x0 asm-arm/arch
 fi

 if [ "$2" = "arm" ] ; then
     rm -f asm-$/proc
     ln -s ${LNPREFIX}proc-armv asm-$/proc
 fi

 #
 # Create include file for Make
 #
 echo "ARCH   = $2" >  config.mk
 echo "CPU    = $3" >> config.mk
 echo "BOARD  = $4" >> config.mk

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

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

 #
 # Create board specific header file
 #
 if [ "$APPEND" = "yes" ]    # Append to existing config file
 then                @APPEND维持原值，所以config.h被重建
     echo >> config.h
 else
     > config.h        # Create new config file
 fi
 echo "/* Automatically generated - do not edit */" >>config.h
 echo "#include <configs/$1.h>" >>config.h

 exit 

这样在执行make smdk2410_config后，在include下面主要添改了四个文件（夹）分别是config.h,   config.mk,   asm-arm/ ,  asm/

其中config.h全部内容如下：

#include<configs/smdk2410.h>

其中config.mk文件内容如下四行

ARCH           =arm

CPU             =arm920t

BOARD        =smdk2410

SOC            =s3c24x0

由此总结执行make  smdk2410_config配置的结果：

1》开发板名称BOARD_NAME=$1

2》建立asm-arm/ ,  asm/和指向到链接

3》创建config.h,定向到开发板smdk2410.h

4》创建config.mk

注意config/下的头文件（包含smdk2410.h）等有两种

1》选项   前缀是CONFIG_

2》参数   前缀是CFG_