Comment # 23 on bug 980570 from Steffen Winterfeldt

I'm currently out of ideas and it will be tricky to make progress without such
a device at my desk. :-(

Issues I've seen:

- the video bios knows only one video mode with an unusual resolution; the
standard gfxboot script doesn't expect this (and doesn't provide a theme in
this resolution), but that can be trivially adjusted

- it seems that the graphics card can only be accessed via framebuffer; but
gfxboot uses the old method via 64k windows mapped at 0xa0000 for drawing; I've
added a patch that changes this (see link below) - and which works at least on
some test machines

- it still doesn't work here; the patch seems to be ok because you can (a) draw
directly by using the framebuffer pointer and do memory writes (the dots you
see with the test isos) and (b) the debug window is visible (it's drawn using
standard internal routines)

- my suspicion atm is that _reading_ from the framebuffer causes problems: it's
done implicitly internally at a number of places and can't be avoided (design
decision from the old times where free memory was scarce); also, maybe strange
mtrr settings are an issue

I've put the current state into the chrome_fb branch (there's some translation
update that slipped into it which can be ignored). When you build the 'test_fb'
theme, you basically get test iso 7.

https://github.com/openSUSE/gfxboot/tree/chrome_fb