From: Pattrick Hueper [mailto:phueper@hueper.net] Hi,
i havent had time to look into seabios. What i read/heard of seabios, it seems, that it is pretty much tied with the x86 architecture, whereas the SLOF biosemu is designed to be architecture independent, and for me it has proven to be so by being ported from OF/PPC to coreboot/x86 with reasonable effort.
Being architecture independent, i think the biosemu has to keep its own set of Interrupt Vectors and virtual 1MB memory area (which is, by the way currently hard coded to 16MB of real memory i think...) That makes it possible to reenter biosemu e.g. for VBE calls (which we did in SLOF, the code is initializing the card by running the Option ROM first and later on reenters biosemu to switch to framebuffer mode). Of course in a x86 coreboot this might need to be redesigned... then again for a x86 coreboot, seabios or vm86 might be the better / faster choices anyway.
I started working on porting v3 to qemu-ppc... once i have some serial output, i will post patches. And i hope to hack qemu-ppc to use the same cirrus vga card and exprom and be able to initialize it in qemu-ppc though it remains to be seen, wether that will work or wether it is already there...
I think this makes your case much stronger. I didn't realize you were porting v3 to PPC. You're right that seabios is x86-specific.
Myles