From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015Ab2KXSYw (ORCPT ); Sat, 24 Nov 2012 13:24:52 -0500 Received: from terminus.zytor.com ([198.137.202.10]:40399 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891Ab2KXSYv (ORCPT ); Sat, 24 Nov 2012 13:24:51 -0500 Message-ID: <50B110CA.5000809@zytor.com> Date: Sat, 24 Nov 2012 10:24:10 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121029 Thunderbird/16.0.2 MIME-Version: 1.0 To: Yinghai Lu CC: "Eric W. Biederman" , Thomas Gleixner , Ingo Molnar , "linux-kernel@vger.kernel.org" , Rob Landley , Matt Fleming Subject: Re: [PATCH v3 11/12] x86, boot: add fields to support load bzImage and ramdisk high References: <1353482170-10160-1-git-send-email-yinghai@kernel.org> <1353482170-10160-12-git-send-email-yinghai@kernel.org> <50AD0CA1.8000904@zytor.com> <50AD291A.10600@zytor.com> <50AE70E7.6060204@zytor.com> <87haofi3d3.fsf@xmission.com> <50B104BC.90208@zytor.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/24/2012 10:12 AM, Yinghai Lu wrote: > > Now I have a fix ready, also found fix for kexec real mode path working > with recently kernel by settin heap end ptr correctly. > > Please decide if we need to add 64 bit entry offset in setup header, > Or just stick to 0x200. > > I check grub2 and gujin and qemu , looks like they are all using bzimage > 16 bit entry. > > Do you have pointer for any boot loader that is using 64 bit entry in > bzimage? > I'm fairly certain Grub2 does *not* use the 16-bit entry point by default even on BIOS platforms, needing the "linux16" directive to behave sanely (this is one of many complete facepalsm in Grub2). efilinux or elilo compiled for a 64-bit EFI platform would be a good example, bit even if we can't find a 64-bit boot loader example I don't think we can rule one out, so let's just define 0x200 as an ABI constant and be done with it. The cost is minimal and the consequences of changing it are potentially severe. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.