From owner-freebsd-smp Fri Jan 3 21:58:33 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id VAA01193 for smp-outgoing; Fri, 3 Jan 1997 21:58:33 -0800 (PST) Received: from who.cdrom.com (who.cdrom.com [204.216.27.3]) by freefall.freebsd.org (8.8.4/8.8.4) with ESMTP id VAA01169 for ; Fri, 3 Jan 1997 21:58:27 -0800 (PST) Received: from cs.utah.edu (cs.utah.edu [128.110.4.21]) by who.cdrom.com (8.7.5/8.6.11) with ESMTP id UAA04551 for ; Fri, 3 Jan 1997 20:55:44 -0800 (PST) Received: from fast.cs.utah.edu by cs.utah.edu (8.8.4/utah-2.21-cs) id UAA10124; Fri, 3 Jan 1997 20:48:18 -0700 (MST) Received: by fast.cs.utah.edu (8.6.10/utah-2.15-leaf) id UAA20659; Fri, 3 Jan 1997 20:40:51 -0700 Date: Fri, 3 Jan 1997 20:40:51 -0700 From: vanmaren@fast.cs.utah.edu (Kevin Van Maren) Message-Id: <199701040340.UAA20659@fast.cs.utah.edu> To: mestery@cobber.cord.edu, smp@csn.net Subject: Re: 486 SMP Cc: freebsd-smp@FreeBSD.ORG Sender: owner-smp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk 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