S3C2416 S3C2450 S3C6410的SD启动卡制作脚本

首先分析u-boot_movi.bin的组成，看uboot的makefile对u-boot.bin的处理：

# Always append ALL so that arch config.mk's can add custom ones
ALL += $(obj)u-boot.srec $(obj)u-boot.bin $(obj)System.map $(U_BOOT_NAND) $(U_BOOT_ONENAND)

all:        $(ALL)

$(obj)u-boot.hex:    $(obj)u-boot
        $(OBJCOPY) ${OBJCFLAGS} -O ihex $< $@

$(obj)u-boot.srec:    $(obj)u-boot
        $(OBJCOPY) -O srec $< $@

$(obj)u-boot.bin:    $(obj)u-boot
        $(OBJCOPY) ${OBJCFLAGS} -O binary $< $@

#$(obj)u-boot_nand.bin:    $(obj)u-boot.bin    //生成u-boot.nand.bin
        @cp -f u-boot.bin u-boot_nand.bin
        chmod 777 u-boot_nand.bin

#$(obj)u-boot_movi.bin:    $(obj)u-boot.bin
# padding to 512k the u-boot.bin
        @cat u-boot.bin > u-boot-2x.bin
        @cat u-boot.bin >> u-boot-2x.bin                                    //合并2个u-boot.bin为  u-boot-2x.bin
        @split -d -a 1 -b 512k u-boot-2x.bin u-boot-512k.bin//从u-boot-2x.bin分离出前512K，实际上= u-boot.bin + BL1，得到u-boot-512k.bin0

# spiliting u-boot for BL1 (8kb)
        @split -d -a 2 -b 8k u-boot.bin u-boot-8k.bin             //取出BL1，得到u-boot-8k.bin00

# creating empty env space (16kb)
#        @dd if=/dev/zero of=empty.env bs=16384 count=1 2> /dev/null  //16K空白的env

# merging the bl1 and env with padded 512k binary
#        @cat empty.env >> u-boot-512k.bin0                        //env追加到u-boot-512k.bin0，这句被屏蔽了，无效
        @cat u-boot-8k.bin00 >> u-boot-512k.bin0                    //BL1（8k）追加到u-boot-512k.bin0

# renaming and change mode
        @mv u-boot-512k.bin0 u-boot_movi.bin                        //u-boot-512k.bin0改名为u-boot_movi.bin
        chmod 777 u-boot_movi.bin

# removing temp files
        @rm -f u-boot-8k*
        @rm -f u-boot-512k*
        @rm -f u-boot-2x*.bin
#        @rm -f empty.env

$(obj)u-boot_movi_256K.bin:    $(obj)u-boot.bin
# padding to 512k the u-boot.bin
        @cat u-boot.bin >> u-boot-2x.bin
        @cat u-boot.bin >> u-boot-2x.bin
        @split -d -a 1 -b 256k u-boot-2x.bin u-boot-512k.bin

# spiliting u-boot for BL1 (8kb)
        @split -d -a 2 -b 8k u-boot.bin u-boot-8k.bin

# creating empty env space (16kb)
#        @dd if=/dev/zero of=empty.env bs=16384 count=1 2> /dev/null

# merging the bl1 and env with padded 512k binary
#        @cat empty.env >> u-boot-512k.bin0
        @cat u-boot-8k.bin00 >> u-boot-512k.bin0

# renaming and change mode
        @mv u-boot-512k.bin0 u-boot_movi.bin
        chmod 777 u-boot_movi.bin

# removing temp files
        @rm -f u-boot-8k*
        @rm -f u-boot-512k*
        @rm -f u-boot-2x*.bin
#        @rm -f empty.env

所以u-boot_movi.bin 的内容实际上为u-boot.bin(512K) + BL1(8K)
按照2416的要求
对于SD卡，uboot 的布局应该是BL2 + BL1(8K) + res(1K)。BL1的块位置为LAST - 18，按起始扇区从0计数则为totalblk - 18。那么u-boot_movi.bin的BL1前面还有u-boot-512k.bin，共(1024个blk)，所以u-boot_movi.bin的块位置应为totalblk - 18 - 1024
对于SDHC卡，uboot 的布局应该是BL2 + BL1(8K) + res(513K)。BL1的块位置为LAST - 1042。按起始扇区从0计数则为totalblk - 1042。u-boot_movi.bin的BL1前面还有u-boot-512k.bin，共(1024个blk)，所以u-boot_movi.bin的块位置应为totalblk - 1042 - 1024

知道了烧写的位置，编写脚本就很简单了，不过我写的脚本还不是很完善，有空再加上格式化SD卡的功能，因为AM335对有MBR的SD卡不支持，当我制作335的SD启动卡时就要对卡进行特殊格式化，去除MBR，回到2416又要恢复MBR，有空再修复335uboot的这个bug。

#!/bin/bash
# Authors:
#    LT Thomas <[e-mail]>
#    Chase Maupin
#    Franklin Cooper Jr.
#
# create-sdcard.sh v0.3

check_for_sdcards()
{
        # find the avaible SD cards
        ROOTDRIVE=`mount | grep 'on / ' | awk {'print $1'} | cut -c6-8`
        PARTITION_TEST=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''`
        if [ "$PARTITION_TEST" = "" ]; then
            echo -e "Please insert a SD card to continue\n"
     while [ "$PARTITION_TEST" = "" ]; do
                read -p "Type 'y' to re-detect the SD card or 'n' to exit the script: " REPLY
         if [ "$REPLY" = 'n' ]; then
                    exit 1
                fi
                ROOTDRIVE=`mount | grep 'on / ' | awk {'print $1'} | cut -c6-8`
                PARTITION_TEST=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''`
            done
        fi
}

# find the avaible SD cards
ROOTDRIVE=`mount | grep 'on / ' | awk {'print $1'} | cut -c6-9`
if [ "$ROOTDRIVE" = "root" ]; then
    ROOTDRIVE=`readlink /dev/root | cut -c1-3`
else
    ROOTDRIVE=`echo $ROOTDRIVE | cut -c1-3`
fi

PARTITION_TEST=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''`

# Check for available mounts
check_for_sdcards

echo -e "\nAvailible Drives to write images to: \n"
echo "#  major   minor    size   name "
cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''
echo " "

DEVICEDRIVENUMBER=
while true;
do
    read -p 'Enter Device Number or 'n' to exit: ' DEVICEDRIVENUMBER
    echo " "
        if [ "$DEVICEDRIVENUMBER" = 'n' ]; then
                exit 1
        fi

        if [ "$DEVICEDRIVENUMBER" = "" ]; then
                # Check to see if there are any changes
                check_for_sdcards
                echo -e "These are the Drives available to write images to:"
                echo "#  major   minor    size   name "
                cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''
                echo " "
               continue
        fi

    DEVICEDRIVENAME=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n '' | grep "${DEVICEDRIVENUMBER}:" | awk '{print $5}'`
    if [ -n "$DEVICEDRIVENAME" ]
    then
            DRIVE=/dev/$DEVICEDRIVENAME
            DEVICESIZE=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n '' | grep "${DEVICEDRIVENUMBER}:" | awk '{print $4}'`
        break
    else
        echo -e "Invalid selection!"
                # Check to see if there are any changes
                check_for_sdcards
                echo -e "These are the only Drives available to write images to: \n"
                echo "#  major   minor    size   name "
                cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n ''
                echo " "
    fi
done

echo "$DEVICEDRIVENAME was selected"

#Check the size of disk to is under 2GB？
#区分SD卡和SDHC
SDTYPE=SD
if [ $DEVICESIZE -gt 2097152 ] ; then
SDTYPE=SDHC
fi

cat << EOM

################################################################################

    Selected Device is $SDTYPE

################################################################################
EOM
echo ""

DRIVE=/dev/$DEVICEDRIVENAME
NUM_OF_DRIVES=`df | grep -c $DEVICEDRIVENAME`

#区分sdx和mmcblkXpY
# This if statement will determine if we have a mounted sdX or mmcblkX device.
# If it is mmcblkX, then we need to set an extra char in the partition names, 'p',
# to account for /dev/mmcblkXpY labled partitions.
if [[ ${DEVICEDRIVENAME} =~ ^sd. ]]; then
    echo "$DRIVE is an sdx device"
    P=''
else
    echo "$DRIVE is an mmcblkx device"
    P='p'
fi
echo " "

#获取总扇区数目
NUM_OF_TOLAL_SECTORS=0
#NUM_OF_TOLAL_SECTORS=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n '' | grep "${DEVICEDRIVENUMBER}:" | awk '{print $4}'`
NUM_OF_TOLAL_SECTORS=`fdisk -l $DRIVE | grep '\\|\' | awk '{print $8}'`
#计算BL2在SD卡中的偏移地址
BL2_OFFSET=0
if [ $SDTYPE = SDHC ] ; then
    let BL2_OFFSET=NUM_OF_TOLAL_SECTORS-1042-1024
else
    let BL2_OFFSET=NUM_OF_TOLAL_SECTORS-18-1024
fi
echo DRIVE = $DRIVE
echo " "
echo NUM_OF_TOLAL_SECTORS = $NUM_OF_TOLAL_SECTORS
echo " "
echo BL2_OFFSET = $BL2_OFFSET
echo " "
dd bs=512 iflag=dsync oflag=dsync if=uboot2416_64M_movi.bin of=$DRIVE seek=$BL2_OFFSET
#卸载DEVICEDRIVENAME磁盘的所有分区

这里有个小技巧，如何获得SD卡总扇区？我想到2种方法，推荐第一种使用截取变量的方法，因为第二种用到的sed是外部命令，严格来讲执行效率较低。

首先要知道，/proc/partitions和fdisk -l显示的blocks都是以KBytes为单位的。扇区=blocks*2

第一种方法，使用截取变量：
#!/bin/bash
input="255 heads, 63 sectors/track, 10443 cylinders, total 167772160 sectors"
output=`echo ${input#*total} | awk '{print $1}'`
echo $output

第二种，使用sed，将total 之前的所有字符替换为空白：
input="255 heads, 63 sectors/track, 10443 cylinders, total 167772160 sectors"
echo $input | sed -e 's/.*total \(.*\) sectors/\1/'
或者使用扩展正则ERE：   echo $input | sed -r -e 's/.*total (.*) sectors/\1/' 

echo "255 heads, 63 sectors/track, 10443 cylinders, total 167772160 sectors" | sed -r -n  's/.*total (.*) sectors/\1/'p
注意-r一定要在-e的前面，因为后面的替换操作是-e选项执行的。

2015.10.21：
获取总扇区数的第三种方法(绝对准确):
由于fdisk-l会因为采用中文导致total变为中文的“总容量”，因为读取/proc/partitions才是最准确的：
NUM_OF_TOLAL_SECTORS=`cat /proc/partitions | grep -v $ROOTDRIVE | grep '\\|\' | grep -n '' | grep  "${DEVICEDRIVENUMBER}:" | awk '{print $4}'`*2 | bc
其中 $ROOTDRIVE=sda  ${DEVICEDRIVENUMBER}=1

注意shell解释器务必选择#!/bin/bash，否则有些命令会报错误，如echo -e， [  ] 等等