From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754709AbXKEUbq (ORCPT ); Mon, 5 Nov 2007 15:31:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751209AbXKEUbf (ORCPT ); Mon, 5 Nov 2007 15:31:35 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39522 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751015AbXKEUbf (ORCPT ); Mon, 5 Nov 2007 15:31:35 -0500 Message-ID: <472F7D8D.8050505@zytor.com> Date: Mon, 05 Nov 2007 12:31:09 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: "Eric W. Biederman" CC: Linus Torvalds , Linux Kernel Mailing List , Thomas Gleixner , Ingo Molnar , Mikael Petterson , Jeremy Fitzhardinge Subject: Re: [GIT PULL] x86 setup: correct booting on 486 (revised) References: <200711050358.lA53wlho003349@tazenda.hos.anvin.org> <472F5941.2060507@zytor.com> <472F61C8.4040300@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; 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: >> >>> However, that being said, doing so is trivial, and it might help some >>> debugging hack; anything that makes debugging easier is a Good Thing[TM]. >> Yeah. Even if it was just re-using the boot-time stack area temporarily, >> just to give code the choice to use a common set of instructions. > > If I had to do it from scratch today I would make the 32-bit entry > point require a stack, segments and use C calling conventions to pass > struct boot_params *. > > Besides %esi I'm not really fond of requiring anything in the 32bit > entrypoint. At the same time I totally agree that it is always nice > to provide way more then you need. > Nailing down the interface as hard as possible is a good idea, to avoid tying your hands for the future. -hpa