That's... not good. I don't know if anyone ever played with Kobos in that state... Hell, I don't even remember how we dealt with Kindles when we could get them in that state, but it involved custom builds of the usual freescale tools (i.e.; fastboot).
If you're feeling adventurous, the gory details are in
this thread on the Kindle side of things (as well as in the Kubrick sticky for a ready-to-use solution).