Hi,
I have a Gigabyte GA-6BXE (Rev 2.1) motherboard with coreboot (built last week, I think). My processor is Intel Pentium III 550 and I have 786 MiB of RAM (actually 1 GiB but the motherboard can't see a part of it). It works just fine when I connect graphics card (ATI Rage II3 or Nvidia GeForce 2 MX) and some other network card I have (I've got 3Com and some other 100 Mb/s NIC). I can even connect both of them and it boots just fine. When I connect Intel PRO/1000 GT Desktop Adapter it doesn't boot. Post card gives me code 0x9B. Nothing appears to my screen nor it reads CD (System Rescue Disk, that is just some random Linux).
I get the same results if I use ATI Radeon 9200SE as the graphics card (last post code is also 0x9B and display is black). Original bios didn't like that graphics card but it at least got into console, just had some "overlapping memory BAR stuff" I don't know much about and thus I couldn't get X working. I haven't tried that Intel NIC with the motherboard's original bios (requires flashing it back). I'd like to get that Intel's card working because I was about to try making a router out of that old hardware.
In addition I noticed that my CD drive didn't work correctly if I connected it to first IDE connector on motherboard. It had some trouble loading Linux and dmesg output following: ata1.00: qc_timeout (cmd 0xa0) ata1.00: TEST_UNIT_READY failed (err_mask=0x4) ata1.00: configured for UDMA/33 which was repeated twice and later it told me that ata1.00: disabled, it was soft resetting link (still ata1.00) and last message about that is "EH complete". After that I couldn't use the CD drive. I don't know if there is something wrong with my hardware, but the other IDE bus works just fine, which I okay, as I don't need more than two devices. I've had problems with that motherboard's IDE bus before still using original bios.
If you are going to make some patches or anything, I'd just like you to know that I don't have any other 'special' equipment than the (cheap) post card, but I have another GA-6BXE (though Rev 1.9) motherboard that beeps continuosly when I boot it (still has the original bios). I might be able to switch the chips, although the chip with coreboot has one leg broken and I use a resistor's leg instead, so it's kind of annoing to fiddle with.
I also tried the motherboard with IWill Sloket and VIA C3 (1 GHz, Nehemiah core), which works nicely with original bios (with 133 MHz×7,5=~1 GHz clock), but it didn't work and the last post code is 0x01. The motherboard has DIP switches for selecting FSB speed and I tried with 100 and 133 MHz settings, neither worked. But that's not the main issue right now, although it would be nice to have that setup working too. I could also try one Socket 370 Celeron if you want. :)
Thanks.
Ps. I hope I didn't make too many typos as it's my second (or third, whatever) language (Finns are odd people, you know ;)) and I wrote this at midnight. Feel free to ask if you don't understand something. I also know that my parts are from different ages and that might be the source of some compatibility issues.