I'd look in src/arch/i386/lib/hardwaremain.c. get_ramsize() in void hardwaremain() seems to be the culprit for RAM size. That's where I've been mucking about trying to do automatic memory sizing for the Epia M. I don't have any specs for the northbridge registers, so it's been slow going. I've been working from the spec sheets for an AMD 762 hoping to hit something. However, The 762 seems to conform better to standards. I also suspect an incorrect RAM size is causing the AGP GART setup code to crash the system both in LinuxBIOS and the AGP drivers in Linux. Good luck, and will somebody let me know when and where RAM sizing is working.