Re: boot hangs at: mtrr: Pentium Pro MTRR support

[Nick Holland <nick@holland-consulting.net>]

O.k., first, have you done a the "disable pcibios" thingie?  I haven't
seen a system which needs that that boots the boot floppy but not
GENERIC, but I'm not going to pretend to have tried every machine out
there or understand all the issues (I'd still love to know why when
trying out pre-release 2.8 stuff, I *never* had a pcibios problem, but
after the master was committed, EVERY SINGLE MACHINE I tried seemed to
have the problem...)

Assuming pcibios isn't it, more comments within...
	
"Russell P. Sutherland" wrote:
> 
> Environment:
> 
>         Dell OptiPlex GXPro
>         64 Mb RAM
>         AHA-2940 SCSI controller
>         DEC500 PCI ethernet card
>         3Com 905 ethernet interface (built-in)
>         System      : OpenBSD 2.8
>         Architecture: OpenBSD.i386
>         Machine     : i386
> 
> Description:
>         I installed OBSD successfully from boot floppy and
>         ftp install. Upon first reboot, the process hangs
>         consistently at the line:
> 
>                 mtrr: Pentium Pro MTRR support
> 
>         I have tried: "boot -c" and disabling mtrr without
>         sucess.

Right idea, but I think you "missed" the trouble maker -- mtrr is
probably the last thing that loaded successfully -- the question is,
what came NEXT?
 
My WAG (Wild..um..Guess) is a probe by the "full" kernel not done by
the "install" kernel is clobbering something.  Another possibility
would be a problem with ISAPNP devices, such as a sound card.  I love
to blame sound cards/chips. 8-)

The GENERIC kernel has a LOT of drivers which are NOT on the boot
floppies.

>         I have used OBSD 2.8 on several other Dell OptiPlex GXPros
>         with IDE drives and no DEC500 NIC without difficulty.

If these other GXPros are IDENTICAL machines (identical to the
engineering staff, not the marketing dept), a dmesg from one of them
-- clearly labled as coming from a different machine! -- might have
been interesting.  On the other hand, it could also be very misleading
(<extreme sarcasm>Would Dell re-use the same name on a totally
different main board?  No, couldn't be.</extreme sarcasm>)

>         This hanging occurs consistently with each reboot
> 
> Has anyone else experienced this or know of a fix?
> 

You state two major differences between this machine and your
"working" machines -- the SCSI adapter and the DEC500 NIC.  So, what
happens when you pull the NIC?  Pull the SCSI adapter and install to
IDE?  If it is the NIC, how about replacing the NIC with another type?

One possible fix would be to pull the "offending" device and recompile
a minimal kernel supporting ONLY the hardware you have in the system,
and maybe that you *might* be inclined to someday install.  Disabling
the on-board sound card might be a worthy attempt.

A true OpenBSD master would probably look at The Source and say "Ah,
The Device Probed for after mttr in GENERIC is xxxxx, disable it, and
you are in business".  I'm not that good. 8)

Nick.
-- 
http://www.holland-consulting.net/