From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754851AbXJWWcc (ORCPT ); Tue, 23 Oct 2007 18:32:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752730AbXJWWcZ (ORCPT ); Tue, 23 Oct 2007 18:32:25 -0400 Received: from terminus.zytor.com ([198.137.202.10]:47091 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752499AbXJWWcY (ORCPT ); Tue, 23 Oct 2007 18:32:24 -0400 Message-ID: <471E766F.7020203@zytor.com> Date: Tue, 23 Oct 2007 15:32:15 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: "Huang, Ying" , Andi Kleen , "Eric W. Biederman" , akpm@linux-foundation.org, Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: [PATCH -v7 1/3] x86 boot: setup data References: <1193126771.23935.79.camel@caritas-dev.intel.com> <471E70E0.2090802@goop.org> <471E729F.3000105@zytor.com> <471E73AB.4050100@goop.org> In-Reply-To: <471E73AB.4050100@goop.org> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge wrote: > H. Peter Anvin wrote: >> No, he doesn't. The boot protocol version is communication between >> the boot loader and the kernel (specifically, it is communication FROM >> the kernel TO the bootloader), not between internal bits of the >> kernel. Th > > So the bootloader will only fill out fields the kernel claims to understand? > Correct. If it fails to respect this restriction, it might even overwrite kernel code. To make the bootloader's job easier, we have retconned the jump instruction at the beginning of the header to also be a limit marker. -hpa