From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266689AbUBQXjy (ORCPT ); Tue, 17 Feb 2004 18:39:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266695AbUBQXjy (ORCPT ); Tue, 17 Feb 2004 18:39:54 -0500 Received: from gate.crashing.org ([63.228.1.57]:60579 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S266689AbUBQXjn (ORCPT ); Tue, 17 Feb 2004 18:39:43 -0500 Subject: Radeon issue on x86 From: Benjamin Herrenschmidt To: Linus Torvalds Cc: Linux Kernel list In-Reply-To: References: <20040217184543.GA18495@lsc.hu> <20040217200545.GP1308@fs.tum.de> <20040217225905.GQ1308@fs.tum.de> Content-Type: text/plain Message-Id: <1077061068.1080.46.camel@gaston> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Wed, 18 Feb 2004 10:37:49 +1100 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Linus ! One of the issue I'm having with raeonfb on x86 is the need to retreive the panel informations out of the BIOS. My current algorithm is to try to retreive that from the PCI ROM of the video chip, and if I cannot find any, then look at the BIOS ROM image in low memory. However, I got a few reports of that not working. Usually, on laptops, apparently, the PCI ROM doesn't exist and it can all be found in the low memory image (I suppose the video BIOS on these is hidden somewhere with the main BIOS and copied to RAM at aboot). BUT, some laptops like some Dell inspirons will show a valid PCI ROM (valid signature) on the video chip, though this ROM appear to not contain any useable panel information table :( However, on these, the RAM image do seem to contain the table... So I would need to reverse my algorithm and default to the RAM BIOS on laptops at least... The problem with the RAM image is that it's only there for the primary display chip that was initialized at boot. So I would need to "know" which PCI card is the primary display. That's all x86 architecture black magic, so I'd like your advice on the best way to do that. Also, that low memory region at c0000, what is it's exact format ? I currently copied a search routine from XFree but it does very little verifications in there, I'm a bit paranoid about picking the wrong thing... What do you suggest ? Ben.