Fair warning: Jumping to a Kobo Touch will save you a lot (and I mean, *a lot*) of hassle).
This is before my time in Kobo-land, but it's in theory similar to what's done on the Kindle 2 (except, much, much worse), possibly the Kindle 1, but since that's also before my time, that's pure conjecture on my part.
So, in increasing order of complexity, you've got:
* Hope that pickel was already implemented on 1.0, as you should be able to feed it a gzipped framebuffer dump somehow (it's 4bpp). Nowadays, it's used to display the boot logo among other things, so, poke into the init scripts, see if something like that exists.
* Delve into the madness that would be trying to plug into the custom Qt4 platform, which, for a start, involves replicating that same setup and toolchain (so, say goodbye to Windows). Good luck.
* Write something custom that talks to the kernel directly. The sources are available with the rest of the Kobo kernels, and the driver is awful, but in there. c.f., include/video/einkio.h & drivers/video/einkfb.c for the kernel stuff, and, as an example, the einkfb implementation in
FBInk for an userland interaction with the aforementioned much nicer Kindle driver
).