uboot——官网下载直接移植(一)

1：uboot下载地址：ftp://ftp.denx.de/pub/u-boot/

我们下载的版本是：u-boot-2013.10.tar.bz2；

2：下载好以后，删除里面的相关文件

因为三星是的s5pv1XX这个cpu做了很多个板子，我们在移植的时候虽然与三星的开发板不同但是用的cpu是相同的，所以我们再选择cpu相关文件的时候，要确定好哪个cpu与

我们用的cpu是相同的，u-boot-2013.10archarmcpuarmv7s5pc1xx 在目录下有s5pc1xx相关的配置文件；这就是我们要选用的cpu文件；

3：相较与我们直接移植三星移植好的uboot，新版的uboot编译配置时有所不同；把主Makefile与board有关的配置信息文件分开了；我们可以根据board.cfg文件中的配置信息来

确定我们用的是哪个开发板；

打开board.cfg文件搜索s5pc1xx我们可以看到两个相关的开发板，goni、smdk100，我们先用goni开发板来进行移植；

首先删除其它的无关文件：

arch目录下：

只保留arm文件夹；arm/cpu目录下的出armv7文件夹以外其他删除；

arm/cpu/armv7目录下保留s5pc1xx 以及s5p_common这两个文件夹，其他的删除；

board目录下：

board目录下只保留samsung文件夹

samsung目录下只保留goni、common文件夹

之后用sourceinsight创建项目

4：对主Makefile进行分析，之前我们make的时候首先要进行配置：make x210_sd_config，而在新uboot中的配置依赖于下面这个规则：

我们进行配置的时候make s5p_goni_config 然后执行下面这段脚本

相当于 执行 ./mkcofig -A s5p_goni  

MKCONFIG变量还是mkconfig脚本，下面我们看一下mkconfig脚本如何工作：

下面这段代码的作用：

if [ ( $# -eq 2 ) -a ( "$1" = "-A" ) ] ; then
    # Automatic mode
    line=`awk '($0 !~ /^#/ && $7 ~ /^'"$2"'$/) { print $1, $2, $3, $4, $5, $6, $7, $8 }' boards.cfg`
    if [ -z "$line" ] ; then
        echo "make: *** No rule to make target \`$2_config'.  Stop." >&2
        exit 1
    fi

    set ${line}
    # add default board name if needed
    [ $# = 3 ] && set ${line} ${1}
fi

判断传参是否两个且 第一个参数为 -A，如果是则 对line赋值，line的值是通过在boards.cfg文件中查找第二个参数$2，并把这一行赋值给line，

从前面内容我们可以看出

line = Active arm armv7 s5pc1xx samsung goni s5p_goni -

并且把这些由空格分开的字符赋值给$1-$8

所以这段代码执行完以后的结果是：

$1 = Active

$2 = arm

$3 = armv7

$4 = s5pv1xx

$5 = samsung

$6 = goni

$7 = s5p_goni

$8 = -

 继续分析下面代码：这段代码实际中没有起到什么作用可忽略

while [ $# -gt 0 ] ; do
    case "$1" in
    --) shift ; break ;;
    -a) shift ; APPEND=yes ;;
    -n) shift ; BOARD_NAME="${7%_config}" ; shift ;;
    -t) shift ; TARGETS="`echo $1 | sed 's:_: :g'` ${TARGETS}" ; shift ;;
    *)  break ;;
    esac
done

[ $# -lt 7 ] && exit 1
[ $# -gt 8 ] && exit 1

下面代码：

CONFIG_NAME="${7%_config}"

[ "${BOARD_NAME}" ] || BOARD_NAME="${7%_config}"

arch="$2"
cpu=`echo $3 | awk 'BEGIN {FS = ":"} ; {print $1}'`
spl_cpu=`echo $3 | awk 'BEGIN {FS = ":"} ; {print $2}'`
if [ "$6" = "-" ] ; then
    board=${BOARD_NAME}
else
    board="$6"
fi
[ "$5" != "-" ] && vendor="$5"
[ "$4" != "-" ] && soc="$4"
[ $# -gt 7 ] && [ "$8" != "-" ] && {
    # check if we have a board config name in the options field
    # the options field mave have a board config name and a list
    # of options, both separated by a colon (':'); the options are
    # separated by commas (',').
    #
    # Check for board name
    tmp="${8%:*}"
    if [ "$tmp" ] ; then
        CONFIG_NAME="$tmp"
    fi
    # Check if we only have a colon...
    if [ "${tmp}" != "$8" ] ; then
        options=${8#*:}
        TARGETS="`echo ${options} | sed 's:,: :g'` ${TARGETS}"
    fi
}

config_name = s5p_goni_config

BOARD_NAME = s5p_goni_config

arch = arm

cpu = armv7

spl_cpu = " "

board = goni

vendor = samsung

soc = s5pc1xx

看下面信息：

在这里第一打印出信息：Configuring for s5p_goni_config board...

if [ "${ARCH}" -a "${ARCH}" != "${arch}" ]; then
    echo "Failed: $ARCH=${ARCH}, should be '${arch}' for ${BOARD_NAME}" 1>&2
    exit 1
fi

if [ "$options" ] ; then
    echo "Configuring for ${BOARD_NAME} - Board: ${CONFIG_NAME}, Options: ${options}"
else
    echo "Configuring for ${BOARD_NAME} board..."
fi

创建头文件的符号连接：

if [ "$SRCTREE" != "$OBJTREE" ] ; then
    mkdir -p ${OBJTREE}/include
    mkdir -p ${OBJTREE}/include2
    cd ${OBJTREE}/include2
    rm -f asm
    ln -s ${SRCTREE}/arch/${arch}/include/asm asm
    LNPREFIX=${SRCTREE}/arch/${arch}/include/asm/
    cd ../include
    mkdir -p asm
else
    cd ./include
    rm -f asm
    ln -s ../arch/${arch}/include/asm asm
fi

rm -f asm/arch

if [ -z "${soc}" ] ; then
    ln -s ${LNPREFIX}arch-${cpu} asm/arch
else
    ln -s ${LNPREFIX}arch-${soc} asm/arch
fi

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

符号连接1：/include/asm 连接到  /arch/arm/include/asm

符号连接2： /include/asm/arch链接到 /arch/arm/include/asm/arch-s5pc1xx

符号链接3： /include/asm/proc链接到/arch/arm/include/asm/proc-armv

看一下下面的代码：

#
# Create include file for Make
#
( echo "ARCH   = ${arch}"
    if [ ! -z "$spl_cpu" ] ; then
    echo 'ifeq ($(CONFIG_SPL_BUILD),y)'
    echo "CPU    = ${spl_cpu}"
    echo "else"
    echo "CPU    = ${cpu}"
    echo "endif"
    else
    echo "CPU    = ${cpu}"
    fi
    echo "BOARD  = ${board}"

    [ "${vendor}" ] && echo "VENDOR = ${vendor}"
    [ "${soc}"    ] && echo "SOC    = ${soc}"
    exit 0 ) > config.mk

这段代码的作用是把

ARCH = arm

CPU = armv7

BOARD  = goni

vendor = samsung

soc = s5pc1xx 输出config.mk文件中

看下面代码：

# Assign board directory to BOARDIR variable
if [ -z "${vendor}" ] ; then
    BOARDDIR=${board}
else
    BOARDDIR=${vendor}/${board}
fi

BOARDDIR = samsung/goni

再看最后一段代码：

# Create board specific header file
#
if [ "$APPEND" = "yes" ]    # Append to existing config file
then
    echo >> config.h
else
    > config.h        # Create new config file
fi
echo "/* Automatically generated - do not edit */" >>config.h

for i in ${TARGETS} ; do
    i="`echo ${i} | sed '/=/ {s/=/    /;q; } ; { s/$/    1/; }'`"
    echo "#define CONFIG_${i}" >>config.h ;
done

echo "#define CONFIG_SYS_ARCH  "${arch}""  >> config.h
echo "#define CONFIG_SYS_CPU   "${cpu}""   >> config.h
echo "#define CONFIG_SYS_BOARD "${board}"" >> config.h

[ "${vendor}" ] && echo "#define CONFIG_SYS_VENDOR "${vendor}"" >> config.h

[ "${soc}"    ] && echo "#define CONFIG_SYS_SOC    "${soc}""    >> config.h

cat << EOF >> config.h
#define CONFIG_BOARDDIR board/$BOARDDIR
#include <config_cmd_defaults.h>
#include <config_defaults.h>
#include <configs/${CONFIG_NAME}.h>
#include <asm/config.h>
#include <config_fallbacks.h>
#include <config_uncmd_spl.h>
EOF

exit 0

上面这段代码的作用就是添加一些宏定义到config.h文件中：

/* Automatically generated - do not edit */

TARGETS为空所以不执行

#define CONFIG_SYS_ARCH　　arm

#define CONFIG_SYS_CPU　　armv7

#define CONFIG_SYS_BOARD　　goni

#define CONFIG_SYS_SOC　　s5pc1xx 

cat << EOF >> config.h 这句代码的作用是把下面内容写入config.h中，直到EOF；