From owner-freebsd-hackers Fri Aug 3 8:48:28 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from netbank.com.br (garrincha.netbank.com.br [200.203.199.88]) by hub.freebsd.org (Postfix) with ESMTP id 8091C37B407; Fri, 3 Aug 2001 08:48:23 -0700 (PDT) (envelope-from riel@conectiva.com.br) Received: from surriel.ddts.net (2-021.cwb-adsl.brasiltelecom.net.br [200.193.161.21]) by netbank.com.br (Postfix) with ESMTP id 5C74646804; Fri, 3 Aug 2001 12:47:52 -0300 (BRST) Received: from localhost (pdtmyz@localhost [127.0.0.1]) by surriel.ddts.net (8.11.4/8.11.2) with ESMTP id f73FmKF24163; Fri, 3 Aug 2001 12:48:20 -0300 Date: Fri, 3 Aug 2001 12:48:20 -0300 (BRST) From: Rik van Riel X-X-Sender: To: Terry Lambert Cc: Julian Elischer , Kenneth Wayne Culver , John Baldwin , , craig Subject: Re: How to visit physical memory above 4G? In-Reply-To: <3B6A369F.C35B7B03@mindspring.com> Message-ID: X-spambait: aardvark@kernelnewbies.org X-spammeplease: aardvark@nl.linux.org MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, 2 Aug 2001, Terry Lambert wrote: > Correct me if I'm wrong, and 64 bit PCI cards can in fact > DMA at offsets above 4G, in the physical address space... They can. And for 32 bit PCI cards you simply use bounce buffers in the same way you handle ISA bounce buffers. It's ugly, but if you have a huge dataset it's better than getting the data from disk. Rik -- Virtual memory is like a game you can't win; However, without VM there's truly nothing to lose... http://www.surriel.com/ http://distro.conectiva.com/ Send all your spam to aardvark@nl.linux.org (spam digging piggy) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message