Peter Stuge wrote: > Stefan Reinauer wrote: > >>>> - YABEL: copy back the IVT, BDA and VBIOS. Some Xorg drivers >>>> require this. >>>> >>> Which drivers? >>> >> As you might imagine I did not test this on the majority of boards, >> so I can't give a full list of Xorg drivers with the problem, >> > > Ah, no, of course not, but it would be great to just list the ones > you know about. > Basically, what happens is that some drivers seem to do BIOS callbacks to set the display modes.
On x86-64 the VGA option rom is executed in x86emu mode, so strictly speaking only a vga option rom is needed at 0xc0000. On x86(-32) systems vm86 is used by Xorg, and the card is (afaik) not (always) re-initialized, so in addition to that the IVT has to be intact. With seabios that is always the case, but with x86emu/yabel and FILO the copying is needed in order to be able to start X. Otherwise the X server will end itself after unsuccessfully attempting to set a mode. For the record, this happened to me on a i945 system with onboard graphics and a not-so-recent debian derivative. Things might be different with newer Xorgs and kernel mode setting, but I don't know for sure. Yet, assuming that the VGA option rom and IVT stays intact is probably fair on an x86 system. Stefan -- coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br. Tel.: +49 761 7668825 • Fax: +49 761 7664613 Email: i...@coresystems.de • http://www.coresystems.de/ Registergericht: Amtsgericht Freiburg • HRB 7656 Geschäftsführer: Stefan Reinauer • Ust-IdNr.: DE245674866 -- coreboot mailing list: coreboot@coreboot.org http://www.coreboot.org/mailman/listinfo/coreboot