Mount image file to partitions

abp

Hi

I downloaded a device firmware.
Like this:
zetnu.xilinx-201907311618-autofreq-user-Update2UBI-NF-sig.tar.gz

I extract above file and file content is these files:

• BOOT.bin
• devicetree.dtb
• rootfs.jffs2
• uImage

Next to this files, was a file yo install.
This file:
runme.sh

This file content is this:
`
#!/bin/sh -e

    path=$(pwd)
    cp_config="all"
    if [ ! -d /mnt/upgrade ];
    then
        mkdir /mnt/upgrade
    fi

    if [ -e /usr/bin/ctrl_bd ]; then
    ret=`cat /usr/bin/ctrl_bd | grep "XILINX" | wc -l`
    else
    ret=0
    fi

    if [ $ret -eq 1 ];then
        cd ./xilinx

        if [ -e /dev/ubi_ctrl ];then

            if [ ! -d /mnt/config ];then
                mkdir /mnt/config
            fi
            ubiattach /dev/ubi_ctrl -m 2
            mount -t ubifs ubi1:rootfs /mnt/config
            if [ ! -d /mnt/config/home/usr_config ];then
                mkdir /mnt/config/home/usr_config
            fi

            if [ `ls /mnt/config/home/usr_config | wc -l` -gt 1 ];then
            cp_config="all" #cp -r /config/* /mnt/config/home/usr_config/
        else
            cp_config="mac" #cp -r /config/mac /mnt/config/home/usr_config/
        fi

        umount /mnt/config
        ubidetach -d 1 /dev/ubi_ctrl
    fi

    if [ -e BOOT.bin ]; then
        flash_erase /dev/mtd0 0x0 0x80 >/dev/null 2>&1
        nandwrite -p -s 0x0 /dev/mtd0 ./BOOT.bin >/dev/null 2>&1
        rm -rf BOOT.bin
    fi

    if [ -e devicetree.dtb ]; then
        flash_erase /dev/mtd0 0x1020000 0x1 >/dev/null 2>&1
        nandwrite -p -s 0x1020000 /dev/mtd0 ./devicetree.dtb >/dev/null 2>&1
        rm devicetree.dtb
    fi

    if [ -e uImage ]; then 
      flash_erase /dev/mtd0 0x1100000 0x40 >/dev/null 2>&1
      nandwrite -p -s 0x1100000 /dev/mtd0 ./uImage >/dev/null 2>&1
      rm uImage
    fi

    if [ -e rootfs.jffs2 ]; then
      if [ -f /dev/mtd3 ];then
          flash_erase /dev/mtd2 0x0 0x1E0 >/dev/null 2>&1
      else
          flash_erase /dev/mtd2 0x0 0x280 >/dev/null 2>&1
      fi
      nandwrite -p -s 0x0 /dev/mtd2 ./rootfs.jffs2 >/dev/null 2>&1
      rm rootfs.jffs2
    fi

    if [ -e /dev/ubi_ctrl ];then
        if [ ! -d /mnt/config ];then
            mkdir /mnt/config
        fi
        ubiattach /dev/ubi_ctrl -m 2
        mount -t ubifs ubi1:rootfs /mnt/config
        if [ ! -d /mnt/config/home/usr_config ];then
            mkdir /mnt/config/home/usr_config
        fi
        if [ $cp_config == "all" ];then
            cp -r /config/* /mnt/config/home/usr_config/
            if [ -e ../lighttpd-htdigest.user ]; then
               line1=`cat ../lighttpd-htdigest.user | wc -c`
               if [ $line1 != "0" ]; then
                   cp -r ../lighttpd-htdigest.user /mnt/config/home/usr_config/lighttpd-htdigest.user
                   if [ -e ../shadow ]; then
                       line2=`cat ../shadow | wc -c`
                       if [ $line2 != "0" ]; then
                           cp /etc/shadow /mnt/config/home/usr_config/shadow
                           old_shd=`sed -n '1p' /mnt/config/home/usr_config/shadow`
                           o1=`echo ${old_shd:5}`
                           o2=${o1#*:}

                           new_shd=`cat ../shadow`
                           n1=$new_shd":"$o2

                           sed -i '1d' /mnt/config/home/usr_config/shadow
                           sed -i "1i $(echo $n1)" /mnt/config/home/usr_config/shadow
                       fi
                   fi
               fi
            fi
        else
            cp -r /config/mac /mnt/config/home/usr_config/
        fi
        sync
        umount /mnt/config
        ubidetach -d 1 /dev/ubi_ctrl
    fi

    if [ -e /dev/ubi_ctrl ];then
        ubiattach /dev/ubi_ctrl -m 2
        mount -t ubifs ubi1:rootfs /mnt/upgrade

        cd /mnt/upgrade/upgrade
        rm -rf /mnt/upgrade/upgrade/*
        cd $path

        if [ -e ./xilinx/angstrom_rootfs.jffs2 ];then
            cp -rf ./xilinx/angstrom_rootfs.jffs2 /mnt/upgrade/upgrade
            if [ -f /dev/mtd3 ];then
                flash_erase /dev/mtd3 0 0xa0 >/dev/null 2>&1
            fi
        fi
        flash_erase /dev/mtd0 0x1040000 0x1 >/dev/null 2>&1
        nandwrite -p -s 0x1040000 /dev/mtd0 ./xilinx/upgrade-marker.bin >/dev/null 2>&1

        sync

        umount /mnt/upgrade
        ubidetach -d 1 /dev/ubi_ctrl
    fi    
else
    echo "this is not for c5"
fi

rm -rf *.tar.gz


#/sbin/reboot -f &

`

Above code used nandwrite to write in a device.

Now, I want to mount these images to a directory or partitions. and add or change somethings to these images. next write again to images.

How can I do it?
Step 1, I just want to mount and read file and directories.

Please help me.

Thanks