From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966791Ab3E2UQY (ORCPT ); Wed, 29 May 2013 16:16:24 -0400 Received: from relay2.sgi.com ([192.48.179.30]:44322 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965519Ab3E2UQT (ORCPT ); Wed, 29 May 2013 16:16:19 -0400 Date: Wed, 29 May 2013 15:16:17 -0500 From: Russ Anderson To: Matt Fleming Cc: Matthew Garrett , matt.fleming@intel.com, linux-efi@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Josh Boyer Subject: Re: [regression, bisected] x86: efi: Pass boot services variable info to runtime code Message-ID: <20130529201616.GB28027@sgi.com> Reply-To: Russ Anderson References: <20130522162747.GA20816@sgi.com> <20130523115801.GJ14575@console-pimps.org> <20130523222321.GB31880@sgi.com> <20130524074544.GM14575@console-pimps.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130524074544.GM14575@console-pimps.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 24, 2013 at 08:45:44AM +0100, Matt Fleming wrote: > On Thu, 23 May, at 05:23:21PM, Russ Anderson wrote: > > Interesting data point. The failure is on a rhel7/grub2 root. > > The identical kernel on a rhel6/grub root boots. So maybe > > grub2 brings out the failure? I suspect Fedora19/grub2 on > > EFI should hit the problem (for someone looking to reproduce > > it). > > > > In both cases the kernel boot line options are the same. > > I'll bet that rhel7 is using the EFI handover protocol which uses the > internal mechanisms of the EFI boot stub. To be more specific (now that I've dug through the code), grub2 (used by rhel7) uses EFI boot stubs. grub and elilo apparently do not use EFI boot stubs, so they don't hit the problem (at least on my test systems). -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com