> There already is a '.code 16' in query_pcbios() at line 688 of head.S, and
> there are no calls and no '.code 32' before the odd behavior I see at line
> 730.

The trace on your post to the bochs list does show 16bit code.
Can you single-step any other instructions?

Maybe the code is continuing from 0:0 after the breakpoint...

 David

-- 
David Laight: david@l8s.co.uk