Success! I've gotten a snapshot of the 5/22/04 sources built, and 
booted single-user. Multi-user gives me "kernel: DTLB miss trap, 
code=0", which I see is attributed to the GCC bug. If this is truly a 
GCC bug, how have the OpenBSD folks gotten around this? Is this due to 
toolchain version differences?

Thanks for all your help, now I should start working on something 
interesting. :)

--Zach