Dear All,

I have a ROM image from my speedtouch router, which you can access it from

http://www.2shared.com/file/3049252/2758df7/image.html

The image contains a few files (one big file that starts with OSI223... (offset 0x311A00) along with several small files). Although I was able to extract all the files by hand, I still don't know about the format of the File System that was used. It is not SquashFS, CramFS or JFFS2. Has anybody seen such a File System used somewhere ?

A few things that I've found out:

Clusters are 512 bytes. The first 4 bytes are FF F6 FF FF (most of the time) and the rest (508 bytes) is data. Every 254 data-cluster is accompanied with a non-data cluster. The root directory table starts with 00 7E FF FF (I think). I didn't see any particular checksum for each cluster or for a group of them.

Thank you very much in advance and sorry if I'm posting it in the wrong forum (in that case I appreciate if you kindly let me know the right forum to forward this question).

Cheers,

You might want to read this thread before spending too much time on the topic.

Hi xaviour,

Thanks a lot for the link. Actually I know all about RSA signature and the problem with modifying the firmware (BTW, there is a simple solution to that, I can simply change the exponent in the RSA to 1 (using jtag) ).

My question wasn't about the possibility of running openwrt on the device, I just needed the format of the file system so that I can extract the files (the file that was attached to my previous email, had only a few files and it is very easy to extract them by hand, but I need an automatic way of doing this for more complex images).

Any more suggestions ?

Thanks in advance,