解压现成的ubi或jffs2的rootfs方法

http://www.at91.com/linux4sam/bin/view/Linux4SAM/SDCardBootNotice

Q: How to extract the files of pre-compiled demo (UBI, JFFS2), and copy them to SD card's ext2/4 partition?

To do this, mount the ubi/jffs2 pre-compiled demo image as a loopback device in your PC, and then copy all files to your SD card's partition.

Here are the steps: (tested in Ubuntu 11.04.)

• Install "mtd-utils" package in PC.

  sudo apt-get install mtd-utils

  
  

• Mount UBIFS images as a loopback:

  modprobe nandsim first_id_byte=0x2c second_id_byte=0xda third_id_byte=0x00 fourth_id_byte=0x15
  modprobe ubi mtd=0
  ubidetach /dev/ubi_ctrl -m 0
  ubiformat /dev/mtd0 -s 2048 -f Angstrom-x11-at91sam9-image-eglibc-ipk-v20110624-at91sam9x5ek.rootfs.ubi
  ubiattach /dev/ubi_ctrl -m 0 -O 2048
  mkdir /mnt/loop
  mount -t ubifs ubi0 /mnt/loop
  cp -R /mnt/loop/* /new/directory
     

  
  

• Mount JFFS2 images as a loopback:

  modprobe nandsim first_id_byte=0x2c second_id_byte=0xda third_id_byte=0x00 fourth_id_byte=0x15
  modprobe mtdblock
  modprobe mtdchar
  modprobe mtd mtd=0
  dd if=Angstrom-x11-at91sam9m10-image-glibc-ipk-2009.X-stable-at91sam9m10g45ek.rootfs.jffs2 of=/dev/mtd0
  mkdir /mnt/loop
  mount -t jffs2 /dev/mtdblock0 /mnt/loop
  cp -R /mnt/loop/* /new/directory/