From owner-freebsd-smp Fri Jan 17 10:03:38 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id KAA16837 for smp-outgoing; Fri, 17 Jan 1997 10:03:38 -0800 (PST) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.8.4/8.8.4) with SMTP id KAA16829 for ; Fri, 17 Jan 1997 10:03:34 -0800 (PST) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id KAA08712; Fri, 17 Jan 1997 10:49:23 -0700 From: Terry Lambert Message-Id: <199701171749.KAA08712@phaeton.artisoft.com> Subject: Re: Adaptec 3940UW and SMP To: smp@csn.net (Steve Passe) Date: Fri, 17 Jan 1997 10:49:22 -0700 (MST) Cc: vanmaren@fast.cs.utah.edu, smp@freebsd.org In-Reply-To: <199701170702.AAA15623@clem.systemsix.com> from "Steve Passe" at Jan 17, 97 00:02:13 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-smp@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > > The Tyan Titan Pro (you have the MP table) also has 5 PCI slots on > > ONE PCI bus. Two of the slots get mapped to the same int. > > However, the MPTABLE only had 4 listed -- I haven't investigated > > further (but the table is in ROM). > ^^^^^^^^^^^^^^^^^^^^^^^ > I have a theory about this, specifically that just because the mptable > program finds the table in "the BIOS", it doesn't mean that the data is > in ROM. Most modern MBs shadow the BIOS from ROM/FLASH to RAM for > speed improvements. This means that they could dynamically build the > MP table however they wanted. Note how we see the MP table for the ASUS > change when going from MP spec 1.1 to 1.4, even though it is at the > same address in the BIOS. Also note how it shows 1 PCI bus without > a PCI bridge card, but 2 with, and how the INT assignments change according > to card placement and BIOS settings. An engineer at Dell assured me that on at least one of their machines, the table was in ROM. This was after a discussion of the MPTable, and how it could be adversely affected by a memory test (back when people were talking about memory tests). He commented that he hadn't considered the possibility when advocating a memory test be done, since Dell places their tables in ROM (as is permitted by the spec). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.