Hi there,

I would like to extract some files from a JFFS2 image taken from an embedded device on SuSE 9.3. Unfortunately I am unable to mount the image.

I tried:

# mount -t jffs2 myimage.jffs2 /mnt -o loop

Result was an error message:

mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

I checked with

# make oldconfig

if the SuSE stock kernel 2.6.11 has support for JFFS2 and it seemingly does have modules for it. So I made sure that the moduls jffs2 was loaded:

# lsmod
Module Size Used by
jffs 39792 0
jffs2 89648 0
mtdcore 7112 2 jffs,jffs2
[...]

Unfortunately I had no success, so far.

Output of dmesg | tail:

JFFS: Trying to mount a non-mtd device.
Attempt to mount non-MTD device "/dev/loop0" as JFFS2
Attempt to mount non-MTD device "/dev/loop0" as JFFS2

Does anyone have a clue what I am doing wrong?

Any hint is much appreciated, thanks in advance!

gargamel

Has really nobody else tried it?
Or is it utterly unclear, what I am asking?

gargamel

No embedded Linux users in the SuSE community...? Can't believe that!!!

Where are you?

gargamel

Um, I'm not really experienced to give anyone advice, but I read in the release notes that JFS is no longer supported. Maybe it's something completely different, and I hope so, but there's my 2 cents. Try reading the release notes to check me on that before you believe it. Good luck!

JFS is only supported up to 9.2, yes.

Ahhh, thanks for your replies, but my question was about JFFS2, not about JFS.

JFFS2 is a file system for flash memory storage. It's used in embedded devices like PDAs, and in Linux distributions like Familiar and ELinOS.

JFS on the other hand is a 'normal' file system for ordinary hard disc drives. It competes with ReiserFS, XFS and all the others. It's from IBM and has a good reputation as a general purpose file system with good overall read and write performance on large and small files alike.

So thanks, but that wasn't it, yet.

gargamel

JFFS2 images need to be mounted through the MTD block device for it to work properly.
This site contains an easy step-by-step to get it done.

http://www.yargybot.com/Familiar/BackupHowto.html


I'll include the super brief summary for posterity.


# modprobe loop
# modprobe mtdblock
# losetup /dev/loop0 /path/to/imagefile.jffs2
# insmod blkmtd erasesz=256 device=/dev/loop0
# mount -t jffs2 /dev/mtdblock0 /mnt