I’ve just realised I’d never actually tried plugging the eframe into my PC. Well, it shows up as a mass storage device with all the photos etc visible on the internal storage. The "PF110.RSS" RSS binary file is visible there. Since its unlikely you’d need to change the RSS feeds themselves very much, this sounds like a far more reliable way to update it than messing about with its braindead network protocols.
So, in summary, I doubt I’ll be continuing development of the python network stuff further; instead I’ll simply use the encoderss.py tool to encode the PF110.RSS file and simply transfer it onto the frame over USB when necessary.
Amusingly the eframe just has a normal partition table with a single FAT16 partition which is set to bootable; I suppose you could use it as a normal USB flash drive and boot an OS off it 🙂
I’m still interested in messing with its firmware though. I’m not sure what the CPU is yet, but it appears to be a 32 bit one. The firmware is compressed in some way, as you’d expect. The hardware appears to have been originally created by a company called "OASIS Semiconductor", who I see were bought by Sigmatel in 2005.