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From: sclawson@bottles.cs.utah.edu (steve clawson)
Message-Id: <199705202149.PAA02983@bottles.cs.utah.edu>
Subject: Re: trap type 29 on P6
To: thorpej@nas.nasa.gov
Date: Tue, 20 May 1997 15:49:43 -0600 (MDT)
Cc: dg@root.com, yokota@zodiac.mech.utsunomiya-u.ac.jp,
        freebsd-hackers@FreeBSD.ORG, freebsd-bugs@FreeBSD.ORG
In-Reply-To: <199705200311.UAA19076@lestat.nas.nasa.gov> from "Jason Thorpe" at May 19, 97 08:11:37 pm
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Jason Thorpe uttered:
> There's not much you can do about it, really... you can't really
> stop the condition from occurring, short of publicly flogging
> purveyors of broken hardware (and it's not clear that'll help
> anyhow). It was fixed in NetBSD-current some time ago by catching
> and ignoring this particular reserved trap vector.

     In this case it's both because of a broken motherboard and a
broken chip. =)  Intel finally put it's errata list on the net
(ftp://download.intel.com/design/{pentium,pro}/update/) and this
particular problem shows up as errata 5AP: Virtual Wire Mode Through
Local APIC May Cause Int 15.  This is supposedly fixed in the very
latest stepping of the Pro.

     Intel's workaround is to have to BIOS disable the local APIC in
uniprocessor machines and in MP's that don't use an I/O APIC.
Probably easier to just ignore the trap though. =)


steve

-- 
// stephen clawson				sclawson@cs.utah.edu
// university of utah