自动解包ROM 文件获取uboot，uboot-spl ,uImage， rootfs.tar.gz 并烧写SD卡

#!/bin/bash
##    Author: Guohua.Wu <Guohua.Wu@nufront.com>
##    Rev: v0.1, Mon Jun 11 16:47:20 CST 2018
##    Description:  Shell script to install SD card with images.

## Open it for debug
set -x
## partition size in MB
BOOTLOAD_RESERVE=16
BOOT_ROM_SIZE=16
EXT4_FS_SIZE=512
##FAT32=TOTAL - EXT
FAT32_FS_SIZE=1024

help() {

    bn=`basename $0`
    cat << EOF
    usage $bn <option> device_node

    options:
    -h                displays this help message
    -s                only get partition size
    -np             not partition.
    -f                 flash image.
EOF
}

echo " check the if root?"
userid=`id -u`
if [ $userid -ne "0" ]; then
    echo "you're not root?"
    exit
fi


# parse command line
moreoptions=1
node="na"
cal_only=0
flash_images=0
not_partition=0
while [ "$moreoptions" = 1 -a $# -gt 0 ]; do
    case $1 in
        -h) help; exit ;;
        -s) cal_only=1 ;;
        -f) flash_images=1 ;;
        -np) not_partition=1 ;;
        *)  moreoptions=0; node=$1 ;;
    esac
    [ "$moreoptions" = 0 ] && [ $# -gt 1 ] && help && exit
    [ "$moreoptions" = 1 ] && shift
done

if [ ! -e ${node} ]; then
    help
    exit
fi


# call sfdisk to create partition table
# get total card size
seprate=0
total_size=`sfdisk -s ${node}`
total_size=`expr ${total_size} / 1024`
boot_rom_sizeb=`expr ${BOOT_ROM_SIZE} + ${BOOTLOAD_RESERVE}`
fat32_size=`expr ${total_size} - ${boot_rom_sizeb} - ${EXT4_FS_SIZE} + ${seprate}`

# create partitions
if [ "${cal_only}" -eq "1" ]; then
cat << EOF
BOOT   : ${boot_rom_sizeb}MB
FAT32  : ${fat32_size}MB
EXT4   : ${EXT4_FS_SIZE}MB
EOF
exit
fi

function format_partitions
{
    echo "formating partitions"
    mkfs.vfat ${node}${part}1  -n"vfat"
    mkfs.ext4 ${node}${part}2  -L"rootfs" 
   # mkdir /media/tmp
   # mount ${node}${part}2 /media/tmp
   # amount=$(df -k | grep ${node}${part}2 | awk '{print $2}')
   # stag=$amount
   # stag=$((stag-32))
   # kilo=K
   # amountkilo=$stag$kilo
   # sleep 1s
   # umount /media/tmp
   # rm -rf /media/tmp
   # e2fsck -f ${node}${part}2
   # resize2fs ${node}${part}2 $amountkilo
}

function flash_filesystem
{
    if [ "${flash_images}" -eq "1" ]; then
    #TODO:: unpack the ROM image
    OUTDIR=/tmp/nufront-sdcard-provision
    POSTFIX='.img'
    [ -d ${OUTDIR} ] && rm -rf ${OUTDIR}
    mkdir ${OUTDIR}
    romfile=$(find ./ -name "*.ROM" | sort  -r | head -n 1)
    unzip ${romfile}  -d ${OUTDIR}
    if [ $? == '0' ]; then
        POSTFIX=''
        cd ${OUTDIR}        
    fi 

       echo "flashing images..."
    dd if=u-boot-spl${POSTFIX} of=${node} bs=512 seek=4096
    if [ ${POSTFIX}"FROMROM" != "FROMROM" ]; then
            dd if=u-boot${POSTFIX} of=${node} bs=512 seek=4608
    else
            dd if=uboot${POSTFIX} of=${node} bs=512 seek=4608
    fi
    dd if=/dev/zero of=${node} bs=512 seek=1536 count=16

    #dd if=rootfs.img of=${node}${part}2
    echo "Unpack the rootfs"
    mkdir /media/tmp
    mount -t ext4 ${node}${part}2 /media/tmp
    tar zxvf rootfs.tar.gz -C /media/tmp
    sync
    umount -f ${node}${part}2
    rm -rf /media/tmp

    echo "Install kernel"
    mkdir /media/tmp
    mount -t vfat ${node}${part}1 /media/tmp
    cp -rf uImage /media/tmp
    sync    
    umount -f ${node}${part}1
    rm -rf /media/tmp
    
    if [ ${POSTFIX}"FROMROM" == "FROMROM" ]; then
         cd -
    fi
    rm -rf ${OUTDIR}
    fi
}

#try to umount the filesystem
df | grep ${node}
if [ $? == 0 ]; then
    echo "Umounting the nodes"
    umount -f ${node}*
fi
#umount -f ${node}*

if [[ "${not_partition}" -eq "1" && "${flash_images}" -eq "1" ]] ; then
    flash_filesystem
    exit
fi

echo "Destroy the partition table"
dd if=/dev/zero of=${node} bs=1024 count=1

boot_start=0
fat32_start=`expr ${boot_start} + ${boot_rom_sizeb} \* 2048`
ext4_start=`expr ${fat32_start} + ${fat32_size} \* 2048`

echo "Making the Partition"
sfdisk --force ${node} << EOF
${fat32_start},${fat32_size}M,83
${ext4_start},${EXT4_FS_SIZE}M,83
EOF

echo "Format the partitions"
part=""
echo ${node} | grep mmcblk > /dev/null
if [ "$?" -eq "0" ]; then
    part="p"
fi

format_partitions
flash_filesystem

sync
sleep 1
echo "Reload the partition table" 
partprobe
echo "Finished!!!"