[ah-]

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.

Edit:
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.

Edit 2:
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.

Edit 3:
And it somewhat works :)