This device is based on the Cirrus "Maverick" strong arm implementation. To my knowledge it is quite hackable, although there is some level of inconvenience - The device won't boot from the smartmedia card without a (presumed small?) change to the onboard firmware. The result would be that you would lose the functionality of the ebook reader in order to use this as a linux device. There is a (rather inactive) web board that you might want to post more -- someone posted about a month ago about starting a Sourceforge project -- it appears that the only tools to communicate with the device at the moment are for windows. I haven't seen this yet, but I would love to use this device as a Linux PDA -- perhaps taking the Agenda project stuff under GPL and adapting it?
The web board - http://broken.blackroses.com/members/rbhack/wwwboard/
I've been sort of dabbling with this (I have this nasty habit of wasting money on toys and never finishing anything, but still cheaper than cigarettes). I'd be happy to help out..
The basic process would probably be -
Create a Linux kernel which knows the Maverick (should be fairly easy) and
supports the flash filesystem on the device (Possibly FAT based?)
- The REB1100 has two roms, one fixed the other flash, and the fixed
rom will boot a binary image.
It should probably support being an USB target so it is easier to
transfer files over.
A "boot loader" which should be simple - it needs to gain control at whatever
location the REB1100 loads the code and copy the Linux kernel into the
right place. The "fixed rom" will load the loader (which could include
the kernel) off the flash
A "boot installer" which ought to be simple, although it might take some
figuring out of the flash filesystem format, or reverse engineering the
onboard "fixed" rom to figure out the entry points to rewrite the onboard
image.
One caveat - Gemstar (who does the content for this device) tends to consider the details about their ram image format and related details to be highly secret and will design like vultures on anyone daring to post such details. With luck sourceforge will tell those clowns where to shove it.