Journaling Flash File System version 2 is a filesystem used with flash memory devices. This is usually found within firmware files and can be detected by binwalk.

Extracting JFFS2 data[edit | edit source]

Most major distros should support JFFS2 already. You may however still need to install the MTD utilities.

# yum -y install mtd-utils

The simplest way to extract contents from a JFFS2 filesystem is to create a virtual flash device and then mount it.

# modprobe mtdram total_size=32768 erase_size=256
# modprobe mtdblock

## Verify
# mtdinfo
# mtdinfo /dev/mtd0

## Copy your image and mount it for extraction
# dd if=extracted.bin of=/dev/mtdblock0
# mount -t jffs2 -o ro /dev/mtdblock0 /mnt/disk

To clean up, just umount the directory and rmmod mtdram.

# umount /mnt/disk
# rmmod mtdram

See also[edit | edit source]