So, I got it to boot by setting CONFIG_AP_CODE_IN_CAR to off. That way the APs don't stumble over one another, and the machine boots just fine.
Here's the boot log:
http://ward.vandewege.net/coreboot/h8dme/minicom-20090624g.cap
You'll see a couple garbled lines, but I think that's just each of the APs saying they are ready.
So, conclusion: commit 4315 broke K8 when CONFIG_AP_CODE_IN_CAR is enabled.
Patrick, do you know why that would be?
Also, what is the benefit, if any, of having CONFIG_AP_CODE_IN_CAR enabled?
Thanks, Ward.