Firmware
This article is about the firmware itself. If you are trying to get a copy of the firmware files, please see Dumping firmware and Extracting firmware. NOTE: Please excuse the chaotic layout of this article. It is under construction. :-)
osos
This is the main firmware partition of the iPod. This part has been encrypted ever since the iPod Nano 2G.
aupd
Here is a comparison between the different aupd partitions of firmware version in the iPod Nano 2G:
rsrc
This is the filesystem of the iPod. It is unencrypted and of not much use to this project.
Helpful pages
http://home.gna.org/linux4nano/download/crypto_synth-1.0.pdf