This tool can be used to view or extract the contents of UBIFS images.
UBIFS is a filesystem specifically designed for used on NAND flash chips. NAND flash is organized in eraseblocks. Eraseblocks can be erased, appended to, and read. Erasing is a relatively expensive operation, and can be done only a limited number of times.
An UBIFS image contains four abstraction layers:
- eraseblocks
- volumes
- b-tree nodes
- inodes
Each eraseblock contains info on how often it has been erased, and which volume it belongs to. A volume contains a b-tree database with keys for:
- inodes, indexed by inode number
- direntries, indexed by inode number + name hash
- datablocks, indexed by inode number + block number
The inodes are basically a standard unix filesystem, with direntries, regular files, symlinks, devices, etc.
modprobe nandsim first_id_byte=0x2c second_id_byte=0xac third_id_byte=0x90 fourth_id_byte=0x26
nandwrite /dev/mtd0 firmware-image.ubi
modprobe ubi mtd=/dev/mtd0,4096
mount -t ubifs -o ro /dev/ubi0_0 mnt
This will mount a ubi image for a device with eraseblock size 0x40000.
If your image has a blocksize of 0x20000, use fourth_id_byte=0x15
, and specify a pagesize of 2048
with the second modprobe line.
View the contents of the /etc/passwd
file in the filesystem image image.ubi
:
python ubidump.py -c /etc/passwd image.ubi
List the files in all the volumes in image.ubi
:
python ubidump.py -l image.ubi
View the contents of b-tree database from the volumes in image.ubi
:
python ubidump.py -d image.ubi
Install the required python modules using:
pip install -r requirements.txt
or as a pip package:
pip install ubidump
You may need to manually install your operarating system libraries for lzo first:
on linux:
apt install liblzo2-dev
on MacOS:
brew install lzo
maybe you need to build the python library like this:
LDFLAGS=-L/usr/local/lib CFLAGS=-I/usr/local/include/lzo pip3 install python-lzo
- python2 or python3
- python-lzo ( >= 1.09, which introduces the 'header=False' argument )
- crcmod
- add option to select a volume
- add option to select a older
master
node - parse the journal
- analyze b-tree structure for unused nodes
- analyze fs structure for unused inodes, dirents
- verify that data block size equals the size mentioned in the inode.
- add support for ubifs ( without the ubi layer )
- add option to extract a raw volume.
- the ubifs/mtd tools http://linux-mtd.infradead.org/
- git repos can be found here
- another python tool on github
- does not support listing files.
- a closed source windows tool here
- ubi-utils/ubidump.c on the mtd mailinglist
Willem Hengeveld [email protected]