From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761312AbXLREfa (ORCPT ); Mon, 17 Dec 2007 23:35:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751240AbXLREfX (ORCPT ); Mon, 17 Dec 2007 23:35:23 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:60976 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbXLREfW (ORCPT ); Mon, 17 Dec 2007 23:35:22 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: "H. Peter Anvin" Cc: Greg KH , "Huang, Ying" , akpm@linux-foundation.org, Thomas Gleixner , Ingo Molnar , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH -mm -v3] x86 boot : export boot_params via sysfs References: <1197620206.12999.12.camel@caritas-dev.intel.com> <20071214155228.GA13342@kroah.com> <4762C78D.9080107@zytor.com> <4762D2CC.1030109@zytor.com> Date: Mon, 17 Dec 2007 21:34:23 -0700 In-Reply-To: <4762D2CC.1030109@zytor.com> (H. Peter Anvin's message of "Fri, 14 Dec 2007 11:00:28 -0800") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "H. Peter Anvin" writes: > This is directly analogous to how we treat identity information in IDE, or PCI > configuration space -- some fields are pre-digested, but the entire raw > information is also available. Add to that a totally unchanged value can just be easier to get correct. Still the kexec code as much as it can should not look there, as we may get the same basic information in a couple of different ways. EFI memmap vs. e820 for example. If/when that is the case /sbin/kexec should get the information and spit it out into whatever format makes sense for the destination kernel. My sense is just passing through values is brittleness where we don't want it. However I think being able to get at the raw boot information overall sounds useful. I just don't know if it is generally useful or just useful when debugging bootloaders though. Eric