"Scott Duplichan" scott@notabs.org writes:
I find with my RS780/SB700 board (ECS A780GM-M3), the initial family 10h AP launch is not reliable. I often see a hang when when all the cores are running in parallel. The parallel execution is apparent if serial logging is enabled, because the characters logged by each core are interleaved. I noticed the AP cores do a few cf8/cfc pci config writes. Could simultaneous access to this shared index/data pair be responsible for the hang? Concerns about such conflicts is why the AMD agesa code does not run cores on the same die in parallel.
This is actually the main reason I fixed MMCONFIG for AMD boards, since that avoids the cf8/cfc race. I would suggest enabling that, but you might have to change the default address range. I believe there's a BAR that's assigned a temporary address by the RS780 code that would clash.