Date: Fri, 3 Jan 1997 20:40:51 -0700 From: vanmaren@fast.cs.utah.edu (Kevin Van Maren) To: mestery@cobber.cord.edu, smp@csn.net Cc: freebsd-smp@FreeBSD.ORG Subject: Re: 486 SMP Message-ID: <199701040340.UAA20659@fast.cs.utah.edu>
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Well, I actually have access to a pre-smp specification 486 system. Made by VTECH, btw. I have sufficient information to get the non-smp compliant parts working, but... The big problem is where the APICs are mapped. There are 3 APICS in a Dual Processor system, and in this box they are all at different addresses (In SMP-compliant systems, the processor APICs are all at the same address). It's not as though they could just be re-mapped, since they are all under 1MB and in the same page. Basically, as long as no-one ever tries to get the processor ID drom the APIC, it should work (You need the processor ID to know what the address of the APIC is). I did write some probe code tha finds the system, but I never tried to bootsrtap the AP (It is slightly different than in a Pentium system). Kevin -- Kevin T. Van Maren University of Utah, CSL
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