From owner-freebsd-hackers@FreeBSD.ORG Mon Jun 9 05:11:43 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 35E4F37B404 for ; Mon, 9 Jun 2003 05:11:43 -0700 (PDT) Received: from mail.speakeasy.net (mail10.speakeasy.net [216.254.0.210]) by mx1.FreeBSD.org (Postfix) with ESMTP id 98CDC43FBD for ; Mon, 9 Jun 2003 05:11:42 -0700 (PDT) (envelope-from jhb@FreeBSD.org) Received: (qmail 18392 invoked from network); 9 Jun 2003 12:11:42 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender )encrypted SMTP for ; 9 Jun 2003 12:11:42 -0000 Received: from laptop.baldwin.cx (laptop.baldwin.cx [192.168.0.4]) by server.baldwin.cx (8.12.9/8.12.9) with ESMTP id h59CBeGI004396; Mon, 9 Jun 2003 08:11:40 -0400 (EDT) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.4 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <200306090752.AA157221012@gatorzone.com> Date: Mon, 09 Jun 2003 08:11:41 -0400 (EDT) From: John Baldwin To: cd_freebsd cc: freebsd-hackers@freebsd.org Subject: Re: Mapping Physical Memory without a Device? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Jun 2003 12:11:43 -0000 On 09-Jun-2003 cd_freebsd wrote: > jmallett@freebsd.org writes > >>> You may also want to consider pmap_map. It depends on what your >>requirements are? > > while Bruce M Simpson [bms@spc.org] writes > >>>It's quite evil and not machine independent..avoid. > > -Who is right? (I like Juli's answer and she has FreeBSD.org in her name :) ) > -Why is pmap_mapdev bad? > -What makes it machine dependent? > -What is the difference between pmap_devmap and pmap_map? > > My requirements would be to map some or all of the following memory areas that are not associated > with any device I own: > 1) BIOS & UMB ram (0xC0000-0xFFFFF) > 2) VGA Video buffer (0xA0000-0xBFFFF) The first 1 meg of memory is 1:1 mapped at KERNBASE. IOW, you can get to the BIOS at KERNBASE + 0xc0000. That should cover these first two items. > 3) Video Frame buffer (0x????0000-0x????0000) Since this is not real RAM but device memory, pmap_mapdev() is ok for this. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/