BTX halted when booting from CD: Toshiba M10-10i laptop

[John Baldwin]

On Wednesday 17 June 2009 1:00:22 pm Gavin Atkinson wrote:
> Hi all,
> 
> I've got a new laptop (a Toshiba M10-10i, for the archives) but FreeBSD
> won't boot on it.  I've tested with the May 2009 amd64 snapshot ISO, and
> about 20% of the time, it hangs before even displaying "CD loader".  The
> rest of the time, I get the following BTX register dump:
> 
> CD Loader 1.2
> 
> Building the boot loader arguments
> Looking up /BOOT/LOADER... Found
> Relocating the loader and the BTX
> Starting the BTX loader
> 
> BTX loader 1.00  BTX version is 1.02
> 
> int=0000000d  err=00003d58  efl=00010246  eip=3583d321
> eax=8b16d000  ebx=00000000  ecx=ffff0000  edx=00002170
> esi=00000000  edi=0003b7c0  ebp=00090bf8  esp=00090bc8
> cs=002b  ds=0033  es=0033    fs=0033  gs=0033  ss=0033
> cs:eip=07 00 00 00 00 00 00 00-33 00 02 00 00 00 00 00
>        00 00 00 00 00 00 00 00-03 00 00 00 20 00 00 00
> ss:esp=5b 3d 03 00 33 00 00 00-48 01 00 00 a0 b0 03 00
>        38 00 00 00 6f 01 20 00-1a 00 20 00 01 94 00 00
> BTX halted
> 
> (at which point the laptop immediately reboots.  This is transcribed
> from a photo.)
> 
> A second crash (some registers are different, but I guess it's the same
> cause due to the same odd eip):
> 
> int=0000000d  err=00003d58  efl=00010202  eip=3583d321
> eax=79f7b814  ebx=00000000  ecx=02000000  edx=000000ec
> esi=00000000  edi=0003b7c0  ebp=00090bf8  esp=00090bcc
> cs=002b  ds=0033  es=0033    fs=0033  gs=0033  ss=0033
> cs:eip=07 00 00 00 00 00 00 00-33 00 02 00 00 00 00 00
>        00 00 00 00 00 00 00 00-03 00 00 00 20 00 00 00
> ss:esp=5b 3d 03 00 48 01 00 00-a0 b0 03 00 38 00 00 00
>        6f 01 20 00 1a 00 20 00-01 94 00 00 00 00 00 00
> BTX halted
> 
> Now, I can tell that eip is off into the weeds, but I'm not really sure
> how to debug this past that.  The first address on the stack is
> presumably a return address, but that doesn't seem to be within the
> address space where any of the bootstrap code is loaded to, so maybe I'm
> wrong. 
> 
> So, how do I continue tracking down the problem from here?
> 
> I don't know if it helps at all, but even a 4.x CD dies in BTX (although
> I haven't managed to successfully take a picture of that to confirm if
> it is the same problem, but can try if it would be useful)
> 
> As an aside, from what I understand from the source, once we've got to
> this stage of the boot the environment should be the same whether we're
> booting from hard drive, CD or PXE?  Is that correct?

My guess is that the data being read from the CD is corrupted somehow.  If a 
4.x CD fails too then that the breakage is solely in the BIOS as 4.x uses the 
old floppy emulation mode.

-- 
John Baldwin