The JFFS2 file system can be extracted with Jefferson, which runs on Python. You can install Jefferson in a pre-existing Python using pip:

sudo apt-get install python3-pip
sudo pip3 install jefferson

The following command creates a folder called “jffs2_extracted” to contain the data extracted from nand.bin.

sudo jefferson -d jffs2_extracted nand.bin

Note: You may see the error

data_crc does not match!

The dump may still be working. Let it continue until the process is complete before trying other steps.

Troubleshooting

If the jffs2_extracted folder contains no data, the offset will need to be removed from the .bin file.

You can determine the offset two ways:

• Using binwalk, look for the address where the JFFS2 file system begins.

binwalk nand.bin

• Using a hex editor such as HxD, look for the following four bytes:

85 20 19 E0

Or

85 19 02 E0

Delete all data before those four bytes and try again to extract with Jefferson.

Note: It is not possible to undelete files from a JFFS2 file system.