From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262217AbTD3QxQ (ORCPT ); Wed, 30 Apr 2003 12:53:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262225AbTD3QxQ (ORCPT ); Wed, 30 Apr 2003 12:53:16 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:44856 "EHLO frodo.biederman.org") by vger.kernel.org with ESMTP id S262217AbTD3QxP (ORCPT ); Wed, 30 Apr 2003 12:53:15 -0400 To: Gabriel Paubert Cc: Jamie Lokier , Andi Kleen , joe briggs , linux-kernel@vger.kernel.org Subject: Re: software reset References: <200304291037.13598.jbriggs@briggsmedia.com.suse.lists.linux.kernel> <20030430075004.GB13859@mail.jlokier.co.uk> <20030430161525.GA3834@iram.es> From: ebiederm@xmission.com (Eric W. Biederman) Date: 30 Apr 2003 11:02:41 -0600 In-Reply-To: <20030430161525.GA3834@iram.es> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Gabriel Paubert writes: > On Wed, Apr 30, 2003 at 05:04:59AM -0600, Eric W. Biederman wrote: > > > > And as an interesting data point all a triple fault does on a modern > > system is to put the cpu in a weird stopped state. Some hardware > > usually the southbridge then detects this and if properly configured > > will trigger the reset line. > > > > I believe this may actually go back into history as far as the 486 but > > I have not done the researched to see how far back this behavior goes. > > Try 286. It was the fastest (actually only) way to make a 286 switch back > from protected to real mode. A triple fault would put a 286 into coma mode? And the hardware had to reset the chip? Just trying to be clear on what you are saying. Eric