From owner-freebsd-hackers Thu Aug 2 22:28:50 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from harrier.mail.pas.earthlink.net (harrier.mail.pas.earthlink.net [207.217.121.12]) by hub.freebsd.org (Postfix) with ESMTP id B17FF37B401; Thu, 2 Aug 2001 22:28:47 -0700 (PDT) (envelope-from tlambert2@mindspring.com) Received: from mindspring.com (dialup-209.244.104.136.Dial1.SanJose1.Level3.net [209.244.104.136]) by harrier.mail.pas.earthlink.net (EL-8_9_3_3/8.9.3) with ESMTP id WAA10534; Thu, 2 Aug 2001 22:28:23 -0700 (PDT) Message-ID: <3B6A369F.C35B7B03@mindspring.com> Date: Thu, 02 Aug 2001 22:29:03 -0700 From: Terry Lambert Reply-To: tlambert2@mindspring.com X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Julian Elischer Cc: Kenneth Wayne Culver , John Baldwin , freebsd-hackers@FreeBSD.org, craig , Rik van Riel Subject: Re: How to visit physical memory above 4G? References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 Julian Elischer wrote: > > No > The space is linear in physical space and if you have PCI/64 > capable devices they can access it all too. > > (In fact 64 bit addresses have been supported even in 32 bit wide PCI > since day 1). It's been my experience that the TIGON cards take a 32 bit DMA target address, not a 64 bit DMA target address, and that the 54 bit width was only used for the data transfer, not for the address offset. Correct me if I'm wrong, and 64 bit PCI cards can in fact DMA at offsets above 4G, in the physical address space... -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message