Thanks to the help of many of you, I have been able to unpack (with FMK), modify some of the files in the rootFS, and repack it (also using FMK).
For a reason that I cannot figure out, I cannot upload the modified firmware to the device.
Things I have tried:
- Uploading modified firmware (Upload doesn't even start, the webapp tells me that the firmware update has failed)
- Uploading unpack/repacked firmware with ZERO changes (Upload doesn't even start, the webapp tells me that the firmware update has failed)
- Uploading firmware from manufacture (Uploads fine, and and update is applied to system, no problems)
When I take the original firmware and just unpack/repack, it is the same size as the original firmware file, but does not hash the same. I'm wondering if there is a checksum somewhere that the firmware update utility uses that fmk does to account for.
I am lost on what to try next. Any ideas or tutorials that you could point me to would really be appreciated.
UPDATE Doing some further investigation, i ran both firmwares (original and repacked original) through a hex diff. I noticed that in the original firmware, everwhere that "0x00 0x01" occurs, in the repacked version, it is replaced with a "0x80 0x00".
I'm hoping that this means something to someone...