BTX halted

[John Baldwin]

On Friday 14 May 2004 05:41 am, Android66 wrote:
> Hi!
>
> Thanks! Disabling DMA works.
>
> Also, I tried booting from a 4.9 CD and floppies (4.9 and 5.2.1-RELEASE)
> and I got the same error. I have disabled everything ACPI related but to
> no avail.
>
> BTW, if it's not a bother, what does the code below actually do? I don't
> speak asm so I can't tell what are the bad things that my BIOS does :)

It tries to see if it is running in protected mode with paging enabled so it 
can walk the page tables to extract physical addresses for its DMA.  The vm86 
monitor that our boot code uses doesn't let the BIOS read the page table 
pointer register (%cr3) so it blows up.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org