From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261733AbUBVTrr (ORCPT ); Sun, 22 Feb 2004 14:47:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261734AbUBVTrr (ORCPT ); Sun, 22 Feb 2004 14:47:47 -0500 Received: from terminus.zytor.com ([63.209.29.3]:5778 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S261733AbUBVTrp (ORCPT ); Sun, 22 Feb 2004 14:47:45 -0500 Message-ID: <40390759.2020201@zytor.com> Date: Sun, 22 Feb 2004 11:47:37 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6b) Gecko/20040105 X-Accept-Language: en, sv, es, fr MIME-Version: 1.0 To: "Eric W. Biederman" CC: linux-kernel@vger.kernel.org Subject: Re: BOOT_CS References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Eric W. Biederman wrote: > hpa@zytor.com (H. Peter Anvin) writes: > >>Anyone happen to know of any legitimate reason not to reload %cs in >>head.S? > > Other than the fact it is strongly rude and error prone to depend on > the contents of a global descriptor table you did not setup? > We already do that, as you might have noticed (we set all the data registers to __BOOT_DS; CS is the only that is changed.) > > That is almost nice. Care to export where the bottom of the page > tables or even better where the bottom of the kernel is for those > folks who want to place their ramdisk as low in memory as possible? > The problem is that you don't know until it's too late, since it can depend on dynamic factors. This is part of why your insistence of putting the ramdisk in the "most incorrect" position is simply wrong. -hpa