I've been looking through the datasheets for my superio (f71882f, not officially supported in coreboot) and the .h and _early_serial.c files for the f71805f (supported in coreboot). It looks like my superio might be compatible. (same addresses/commands etc). Is it worth a try? My COM1 port's fried and my COM2 port doesnt seem to work, although I think the latter might be an issue with the BIOS disabling it. If that's the case, how easy would it be to get a basic coreboot image on my board with serial debugging? RAM etc can come later. It looks like EHCI debug is possible on my motherboard, but at $90 each, I can't really afford a debugger - my motherboard cost half that.