> I compile GENERIC or variant thereof with amd support, the thing
> crashes.  The trace output is below.  
>
> Also, would anyone be kind enough to tell me what some of this means?

Can you include the following in your kernel?

options APMDEBUG
options APMDEBUG_VALUE 0xff

> apm0 at mainbus0: uvm_fault(0c0386180, 0xd000, 0, 1) -> 1
> kernel: page fault trap, code=0
> Stopped in swapper at   trap+0x207:     movzbl  0(%eax),%eax

Anyhow, I was seeing the same effect when the APM BIOS used a data segment
outside the expected range.  The following kernel option is used
specifically to address this problem:

options APM_ALLOW_BOGUS_SEGMENTS

	-- Gregory McGarry <g.mcgarry@ieee.org>