Hello,
Sorry for my bad english.
I'm going to try coreboot on Gigabyte GA-MA770-UD3. It's AMD 770 (RX780 / SB700).
I've prepared the image for it based on code for mahogany fam10 with some modifications.
I've tried it with simnow using the configuration close to mine as much as possible - it even boots with my native BIOS. And it boots with coreboot image.
My motherboard supports hardware dual bios - with two chips on it. I'm going to try flashing backup chip and boot from it. It seems to be possible - I've tested it (flashing at least). Chips on this board could be switched by changing bit 0 at undocumented register EF on LDN 7 of IT8720. I can use slightly patched flashrom for accessing any chip I want without any problems. And this is tested many times.
My idea is to use backup chip for debugging - that always keeps my chance to reboot from main bios chip. And removes the need for desoldering etc.
But the problems are when I'm trying to boot - and I expected them. It seems that after warm reboot it is trying to boot from selected chip as I want, but reboots againg in a second. AFAIK there is some hardware watchdog on these dualbios motherboards. There are many possibilities - northbridge, southbridge, superio.
My main question is - is anybody working on it or may be have some info on it. I definitely will find the way to turn the watchdog off but may be somebody already did that?
And second problem is that original bios is checking second chip - and trying to recover it by flashing the bios from main chip on reboot? rewriting coreboot. AFAICS this could be solved by including some signatures etc. It seems to be easy to find out. May be someone is working on this?
BTW I can send the patch for flashrom - but I think that with information I mentioned above somebody could make it much better than my ugly hack. I hope the regs should be the same for all latest Gigabyte MBs using IT8720/18
Please, post any info you have that can help me.