I don't have ICE (Could you recommend one ?).
I suppose Ron knows much more about them than I do.
All we have here is American Arium ECM 20.
Therefore I printed post code at several point of bochs code. And I think it stop during VGABIOS execution because it works before option rom scan procedure. I think EPIA bios do something on northbridge settings which VGABIOS require. How do you think?
It is possible. It was one of those things that I hoped warm boot would take care of.
Another idea to try. I'm not actually sure if BOCHS BIOS would boot without the VGABIOS but it should be possible, so. ( I assume u have here Port 80 card.) First unboundle vga bios. ie does not include it at all. Then write a simple boot sector which sets port 80 to something and see if you can get that far.
Also this way you sould be able to take care problems in bochs bios which are not related to video. It could potentially make trying to take care of video easier.
if the binary only vga bios comes out to be useless you could grab video bios from boch's project and try to adapt that one instead.
I found some VGA related registers on northbridge such as 0xfb register which have 'VGA Enable' disable bit. However When I enable it, strangely etherboot doesn't works and system restarted. (My boot configuration is linuxbios -> etherboot -> ADLO payload )
I guess ICE makes life easier.