From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752879Ab0FMAH7 (ORCPT ); Sat, 12 Jun 2010 20:07:59 -0400 Received: from relay2-v.mail.gandi.net ([217.70.178.76]:40226 "EHLO mrelay2-v.mgt.gandi.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752828Ab0FMAH6 (ORCPT ); Sat, 12 Jun 2010 20:07:58 -0400 X-Greylist: delayed 8535 seconds by postgrey-1.27 at vger.kernel.org; Sat, 12 Jun 2010 20:07:58 EDT X-Originating-IP: 217.70.178.44 X-Originating-IP: 74.107.143.84 Date: Sat, 12 Jun 2010 17:07:43 -0700 From: Josh Triplett To: "H. Peter Anvin" Cc: Ben Hutchings , x86@kernel.org, 584846@bugs.debian.org, LKML Subject: Re: Bug#584846: Detects only 64MB and fails to boot on Intel Green City board if e820 hooked by GRUB2 Message-ID: <20100613000742.GA3469@feather> References: <20100612060322.29053.94187.reportbug@feather> <1276351120.14011.194.camel@localhost> <4C13D1E7.7060604@zytor.com> <20100612185538.GA4511@feather> <4C13F102.7000509@zytor.com> <20100612222634.GA1785@feather> <4C141214.5050601@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C141214.5050601@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 12, 2010 at 04:02:44PM -0700, H. Peter Anvin wrote: > On 06/12/2010 03:26 PM, Josh Triplett wrote: > > > > Everything looks identical except for the region GRUB hooked right below > > the first reserved region; the unhooked version has available memory > > from 0-0x9cbf0, and the hooked version has available memory from > > 0-0x9cba0, then reserved from 0x9cba0-0x9cbec, then 4 bytes of available > > memory, and then the same reserved region as before. > > Actually... are both these done by chainloading Grub (with and without > mapping), or is the unhooked done without chainloading Grub at all? > > To me it looks like something is chaining INT 15h even in the > "unchained" case... The "unhooked" case still chainloaded from GRUB, just without calling drivemap and thus without hooking anything. I can test without chainloading from GRUB, though to the best of my knowledge GRUB doesn't hook int 15 unless it needs to intercept e820 (and e801 and 88). - Josh Triplett