I spent a little time today slowly bringing up the NitrOS-9 Level 1 kernel on the Liber809. With the sound emission and screen color code, I was able to track the progress of the kernel through the various stages (clearing memory, installing system calls, validating modules, etc) up to the point where it's now opening the /Term device. I have a dummy VTIO driver that pretty much does nothing in the Init routine except tell the ANTIC to show a light purple screen. The next step will be to actually get characters on the screen. For that, I'll need to hit the Atari docs pretty hard.
The bootfile is minimal right now and consists of Krn, KrnP2, IOMan, SCF, VTIO, Term, and Sysgo.