From owner-freebsd-x11@FreeBSD.ORG  Mon Oct  8 00:41:10 2007
Return-Path: <owner-freebsd-x11@FreeBSD.ORG>
Delivered-To: freebsd-x11@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 08BC816A520
	for <freebsd-x11@freebsd.org>; Mon,  8 Oct 2007 00:41:10 +0000 (UTC)
	(envelope-from wblock@wonkity.com)
Received: from wonkity.com (wonkity.com [67.158.26.137])
	by mx1.freebsd.org (Postfix) with ESMTP id 93B0F13C465
	for <freebsd-x11@freebsd.org>; Mon,  8 Oct 2007 00:41:09 +0000 (UTC)
	(envelope-from wblock@wonkity.com)
Received: from wonkity.com (localhost [127.0.0.1])
	by wonkity.com (8.14.1/8.14.1) with ESMTP id l980f8kB001973
	for <freebsd-x11@freebsd.org>; Sun, 7 Oct 2007 18:41:08 -0600 (MDT)
	(envelope-from wblock@wonkity.com)
Received: from localhost (wblock@localhost)
	by wonkity.com (8.14.1/8.14.1/Submit) with ESMTP id l980f8Vt001970
	for <freebsd-x11@freebsd.org>; Sun, 7 Oct 2007 18:41:08 -0600 (MDT)
	(envelope-from wblock@wonkity.com)
Date: Sun, 7 Oct 2007 18:41:08 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: freebsd-x11@freebsd.org
Message-ID: <20071007183313.O1942@wonkity.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0
	(wonkity.com [127.0.0.1]); Sun, 07 Oct 2007 18:41:08 -0600 (MDT)
Subject: Re: Using /dev/mem to read video BIOS ROM
X-BeenThere: freebsd-x11@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: X11 on FreeBSD -- maintaining and support <freebsd-x11.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-x11>,
	<mailto:freebsd-x11-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-x11>
List-Post: <mailto:freebsd-x11@freebsd.org>
List-Help: <mailto:freebsd-x11-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-x11>,
	<mailto:freebsd-x11-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 08 Oct 2007 00:41:10 -0000

Following up to my own question:

No, you can't just read a video BIOS ROM directly.  The main video card 
BIOS is at 0xc0000 because it is shadowed there.  To read a BIOS ROM 
directly from the card, you have to enable the ROM and map it into an 
area of memory.

The good news is that Xorg already has routines to do this, and with a 
small fix*, they work correctly on FreeBSD.

* http://lists.freedesktop.org/archives/xorg/2007-October/029005.html

-Warren Block * Rapid City, South Dakota USA