用shell获取SD卡总扇区数目，S3C2416 6410烧写SD卡需要用到

neversoft

我参考了TI官网am335版块提供的create-sdcard.sh脚本，部分源码如下：
# find the avaible SD cards
echo " "
echo "Availible Drives to write images to: "
echo " "
ROOTDRIVE=`mount | grep 'on / ' | awk {'print $1'} |  cut -c6-8`
echo "#  major   minor    size   name "
cat /proc/partitions | grep -v $ROOTDRIVE | grep '\<sd.\>' | grep -n ''
echo " "

ENTERCORRECTLY=0
while [ $ENTERCORRECTLY -ne 1 ]
do
    read -p 'Enter Device Number: ' DEVICEDRIVENUMBER
    echo " "
    DEVICEDRIVENAME=`cat /proc/partitions | grep -v 'sda' | grep '\<sd.\>' | grep -n '' | grep "${DEVICEDRIVENUMBER}:" | awk '{print $5}'`

    DRIVE=/dev/$DEVICEDRIVENAME
    DEVICESIZE=`cat /proc/partitions | grep -v 'sda' | grep '\<sd.\>' | grep -n '' | grep "${DEVICEDRIVENUMBER}:" | awk '{print $4}'`


    if [ -n "$DEVICEDRIVENAME" ]
    then
        ENTERCORRECTLY=1
    else
        echo "Invalid selection"
    fi

    echo ""
done

echo "$DEVICEDRIVENAME was selected"
#Check the size of disk to make sure its under 16GB
if [ $DEVICESIZE -gt 17000000 ] ; then
cat << EOM

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

        **********WARNING**********

    Selected Device is greater then 16GB
    Continuing past this point will erase data from device
    Double check that this is the correct SD Card

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

EOM

我们只需要取总块数，没必要那么麻烦，只需：

cat /proc/partitions | grep -v 'sda' | grep '\<sd.\>' | grep -n '' | grep "1:" | awk '{print $4}'

15558144
即可得到扇区数，我的16G卡是15558144。接下来就可要用dd命令烧写u-boot到指定位置（2416、6410要求在u-boot必须放在sd卡末尾的一段区域，具体请看cpu对应的irom启动应用笔记）。需要注意的是，上述代码只针对SD卡挂载在sdb路径下，如果你的挂载路径不一样，需要修改一下。