When I tried to run coreboot under qemu, I was at first positively surprised how well the things worked. The BIOS + linux kernel payload booted in no time! But when I then tried to set up networking, I couldn't get that to work. Somehow the linux kernel couldn't locate the interrupts of the NIC. After some digging I found out that coreboot doesn't provide ACPI tables and instead uses PCI IRQ table (I had to extract this table from a running qemu system using the getpir utility and then copy it to coreboot, if you want that patch, I can send that too). Coreboot copies this table at runtime into memory at 0xf0000. Apparently 0xf0000-0xfffff is part of the ISA BIOS, and qemu marks this range as read-only. The attached patch for qemu fixes that and also cleans up some of the memory initialization. Instead of marking the ISA BIOS as read-only, it copies that part from the BIOS image into the appropriate place (at 0xf0000-0xfffff) and leaves the memory as read-write.
tom