From owner-freebsd-hackers@FreeBSD.ORG Mon May 23 12:20:09 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C8C1B16A41C for ; Mon, 23 May 2005 12:20:09 +0000 (GMT) (envelope-from walter.pelissero@iesy.net) Received: from smtp.iesy.net (mta002.iesy.net [81.210.131.41]) by mx1.FreeBSD.org (Postfix) with ESMTP id 64B5C43D48 for ; Mon, 23 May 2005 12:20:01 +0000 (GMT) (envelope-from walter.pelissero@iesy.net) Received: from zaphod.home.loc (unknown [81.210.131.48]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.iesy.net (Postfix) with ESMTP id B86B1B532 for ; Mon, 23 May 2005 14:19:55 +0200 (CEST) Received: from zaphod.home.loc (localhost [127.0.0.1]) by zaphod.home.loc (8.13.3/8.13.3) with ESMTP id j4NCJfKr018784 for ; Mon, 23 May 2005 14:19:41 +0200 (CEST) (envelope-from wcp@zaphod.home.loc) Received: (from wcp@localhost) by zaphod.home.loc (8.13.3/8.13.1/Submit) id j4NCJeG8018781; Mon, 23 May 2005 14:19:40 +0200 (CEST) (envelope-from wcp) From: "Walter C. Pelissero" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17041.51804.39393.691186@zaphod.home.loc> Date: Mon, 23 May 2005 14:19:40 +0200 To: freebsd-hackers@freebsd.org X-Mailer: VM 7.19 under Emacs 22.0.50.1 X-Attribution: WP X-For-Spammers: blacklistme@pelissero.de X-MArch-Archive-Date: 2005-05-23 14:19:41 X-MArch-Archive-ID: 2381 X-MArch-Processing-Time: 0.17s X-Mailman-Approved-At: Mon, 23 May 2005 12:31:23 +0000 Subject: Tyan S2460 and btx.S X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: walter@pelissero.de List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 May 2005 12:20:09 -0000 Apparently FreeBSD 5.x is neither able to power off nor reset a Tyan Tiger MP (S2460) motherboard. I believe it's a known problem. While the power off may be due to a broken ACPI the reset can be fixed. Revision 1.33 log of /sys/boot/i386/btx/btx/btx.S says: date: 2003/11/16 18:24:23; author: phk; state: Exp; lines: +1 -1 When rebooting the machine jump to 0xf000:0xfff0 instead of 0xffff:0x0. While we end up the same place, we end up with two different CS register values after the jump and 0xf000 is compatible with the hardware reset value. This makes a difference if the BIOS does a near jump before a far jump. Detective work and patch by: Adrian Steinmann I tried reverting the patch and now the Tyan motherboard seems to reset as expected. My knowledge of the PC architecture intricacies is not good enough to discuss the merits of revision 1.33 patch, but I believe it could be worth having an ifdef-ed code in btx.S to accommodate motherboards like this one. -- walter pelissero http://www.pelissero.de