Ok, with devcap-daemon working the framework seems to start.
The screen stays black, and strace says it waits for a futex, so I guess it requires some other service to start up properly. But I'll investigate that later.
After a bit more poking around and especially executing /etc/upstart/firstboot and prereg.conf manually as well as unpacking more cramfs.img from /etc/loopbacktab and setting the framebuffer to 8bit thanks to your framebuffer_configure it now really starts , still with tons of errors but I get a white window and touching the screen results in messages in the log. I see exceptions about missing images, but I haven't found out yet which images are missing and why.
Starting the onscreen keyboard (/usr/bin/kb) leads to the same error and is a lot less complex, so probably investigating that is easier.
So it seems that this is just what you hinted at in the first posts, the screen update is different. I'm still looking at it, but I suspect awesome (the window manager) to be somehow responsible for it. Starting it pretty much corrupts the display, but upon a closer look the onboard keyboard letters are there in between the corruption.
And it somewhat works :)
Last edited by ah-; 01-30-2013 at 04:57 PM.