Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964862AbWHLPXd (ORCPT ); Sat, 12 Aug 2006 11:23:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964878AbWHLPXc (ORCPT ); Sat, 12 Aug 2006 11:23:32 -0400 Received: from mx1.redhat.com ([66.187.233.31]:13955 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S964862AbWHLPXa (ORCPT ); Sat, 12 Aug 2006 11:23:30 -0400 Date: Sat, 12 Aug 2006 11:25:55 -0400 From: Don Zickus To: "Eric W. Biederman" Cc: vgoyal@in.ibm.com, fastboot@osdl.org, Horms , Jan Kratochvil , "H. Peter Anvin" , Magnus Damm , linux-kernel@vger.kernel.org Subject: Re: [Fastboot] [CFT] ELF Relocatable x86 and x86_64 bzImages Message-ID: <20060812152555.GB16068@redhat.com> References: <20060807235727.GM16231@redhat.com> <20060809200642.GD7861@redhat.com> <20060810131323.GB9888@in.ibm.com> <20060810181825.GD14732@in.ibm.com> <20060811212522.GF18865@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1938 Lines: 47 On Sat, Aug 12, 2006 at 01:20:29AM -0600, Eric W. Biederman wrote: > Don Zickus writes: > > >> >> > >> >> I'm a little disappointed but at this point it isn't a great surprise, > >> >> the code is early yet and hasn't had much testing or attention. > >> >> I wonder if I have missed something else silly. > >> >> > >> >> As for testing, can you use plain kexec to load the kernel at a > >> >> different address? I'm curious to know if it is something related > >> >> to the kexec on panic path or if it is just running at a different > >> >> location that is the problem. > >> > > > > > I think I have found the 'something silly'. Here is a patch that allows > > our Dell em64t boxes to boot. This change matches the original code. The > > main difference that caused the problems was the setting of _PAGE_NX bit. > > This caused issues in early_io_remap(). > > > > Thanks to Larry Woodman for debugging this. > > This looks like a different one but looks fairly sane. > > Do you know what code had problems having _PAGE_NX set. > What are we doing with early_ioremap the requires execute > permissions. It doesn't sound right that we would need > this. This fix is only needed for a subset of our em64t boxes, so it could be just a chipset problem. Supposedly, if I remember the conversation correctly, when the kernel first boots it reserves about 40MB and about 20 pmds automatically. After decompression, early_io_remap tries to setup all the memory. The conflict arose when early_io_remap tried to reuse one of those pmds. This caused the system to crash and reboot. I'll try to get more info Monday on the specifics. Cheers, Don > > Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/