Full tech specs and white papers are on Marvell's website.
http://www.marvell.com/processors/ap...ns/armada_100/
From some searches it seems PXA support is in the newer mainline kernel.
Good find on the other tablet I'll poke around in that rom and see if I can find anything of use.
By the way if you want to have access to the recovery just zip an empty update.sh. It will hang at 3 dots as normally the update script changes the screen here. Connect via adb and you have root access in the recovery. Good to familarize yourself if you plan on modifying if the update script as mount points are diff.