From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965220AbXBFSNV (ORCPT ); Tue, 6 Feb 2007 13:13:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964784AbXBFSNV (ORCPT ); Tue, 6 Feb 2007 13:13:21 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:60551 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965220AbXBFSNU (ORCPT ); Tue, 6 Feb 2007 13:13:20 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Etienne Lorrain Cc: "H. Peter Anvin" , vgoyal@in.ibm.com, linux-kernel@vger.kernel.org Subject: Re: Re : [PATCH] Compressed ia32 ELF file generation for loading by Gujin 1/3 References: <957176.28334.qm@web26903.mail.ukl.yahoo.com> Date: Tue, 06 Feb 2007 11:12:39 -0700 In-Reply-To: <957176.28334.qm@web26903.mail.ukl.yahoo.com> (Etienne Lorrain's message of "Tue, 6 Feb 2007 17:23:55 +0000 (GMT)") 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 X-Mailing-List: linux-kernel@vger.kernel.org Etienne Lorrain writes: > H. Peter Anvin wrote: >> Actually, as far as I can see, he has re-invented having a real-mode >> code chunk which then gets run before the protected-mode kernel. We >> already have that! > > I did not claim to have invented anything there, this is just a quite > simple C code to execute instead of the current real mode assembly: > it is a rewrite with obvious advantages/disadvantages. > New features are more that this real-mode function can return an error > to the bootloader to tell something to the user, so the user can select > another kernel with the right processor, another video mode... with > clean error messages - not a crash dump because this assembly > instruction is not for that processor. Having an error handling compatibility that is backwards compatible sounds interesting. > I am still saying that the bootloader knows the root filesystem to > be used by the kernel it loads, and that ELF is a clean format to > store different sections to be loaded into memory at predefined > addresses. Yes. Although when you think sections instead of segments I'm a little worried. > Also there isn't any more kernel size limit. I think as HPA points out we have gotten past that a long time ago with the bzImage format. With the right delicacy, and preserving backwards compatibility with existing bootloaders I think we can achieve things. The big issue is that sometimes bootloaders are a little bit brittle. Eric