After the release of the first firmware update, I'd like to get cracking on this.
So far, I've opened the yaffs2 image supplied with the firmware update and had a bit of a poke about to see what's what. Basically a 'base' filesystem is in the image (with the usual tiny linux distro - modules, busybox, etc) and a 'usr.tgz' file included in root - the init script checking for the existence of said file on boot and just untarring it out to /usr, transferring control to the Kobo software afterwards. Ta-da! Upgraded software.
Interestingly, the script also mounts the SD card and checks for the existence of a couple of files - if so, they appear to be executed at boot, which would make it an easy way to get stuff onto the device.
Bluetooth is enabled in the kobo, and it looks like one could use RFCOMM to get a console via bluetooth (rfcomm0/1 are present in /dev), but it's been a long time since I've done anything with bluetooth and linux.
So, as someone who just stumbled across OI one day and has only a smattering of embedded experience..... where to from here?
I've attached the kobo base layout, and the init script if anyone's interested. I've left the actual kobo software out as it's kobo's, and it's 35MB.