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 :

1 smdk2410_config    :    unconfig

2     @$(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：

 1 #!/bin/sh -e

 2 

 3 # Script to create header files and links to configure

 4 # U-Boot for a specific board.

 5 #

 6 # Parameters:  Target  Architecture  CPU  Board [VENDOR] [SOC]

 7 #

 8 # (C) 2002-2006 DENX Software Engineering, Wolfgang Denk <[email protected]>

 9 #

10 

11 APPEND=no    # Default: Create new config file

12 BOARD_NAME=""    # Name to print in make output

13 

14 while [ $# -gt 0 ] ; do          @@$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0

15     case "$1" in             @因为上面的$(@:_config=)把smdk2410_config的_config替换为空，所以不存在_

16     --) shift ; break ;;     @所以这个循环不动作

17     -a) shift ; APPEND=yes ;;

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

19     *)  break ;;

20     esac

21 done

22 

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

24 

25 [ $# -lt 4 ] && exit 1

26 [ $# -gt 6 ] && exit 1

27 

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

29 

30 #

31 # Create link to architecture specific headers

32 #

33 if [ "$SRCTREE" != "$OBJTREE" ] ; then

34     mkdir -p ${OBJTREE}/include

35     mkdir -p ${OBJTREE}/include2

36     cd ${OBJTREE}/include2

37     rm -f asm

38     ln -s ${SRCTREE}/include/asm-$2 asm

39     LNPREFIX="../../include2/asm/"

40     cd ../include

41     rm -rf asm-$2

42     rm -f asm

43     mkdir asm-$2

44     ln -s asm-$2 asm

45 else

46     cd ./include

47     rm -f asm

48     ln -s asm-$2 asm

49 fi                               @@上面是建立或者删除一些目录

50 

51 rm -f asm-$2/arch                @rm -f asm-arm/arch

52 

53 if [ -z "$6" -o "$6" = "NULL" ] ; then          @$6=s3c24x0  不为空  所以执行else

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

55 else

56     ln -s ${LNPREFIX}arch-$6 asm-$2/arch    @LNPREFIX为空 所以相当于ln -s arch-s3c24x0 asm-arm/arch

57 fi

58 

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

60     rm -f asm-$2/proc

61     ln -s ${LNPREFIX}proc-armv asm-$2/proc

62 fi

63 

64 #

65 # Create include file for Make

66 #

67 echo "ARCH   = $2" >  config.mk

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

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

70 

71 [ "$5" ] && [ "$5" != "NULL" ] && echo "VENDOR = $5" >> config.mk

72 

73 [ "$6" ] && [ "$6" != "NULL" ] && echo "SOC    = $6" >> config.mk

74 

75 #

76 # Create board specific header file

77 #

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

79 then                @APPEND维持原值，所以config.h被重建

80     echo >> config.h

81 else

82     > config.h        # Create new config file

83 fi

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

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

86 

87 exit 0

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_