From owner-freebsd-hackers Fri Aug 3 10:46:41 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from InterJet.elischer.org (c421509-a.pinol1.sfba.home.com [24.7.86.9]) by hub.freebsd.org (Postfix) with ESMTP id 3DD4437B406; Fri, 3 Aug 2001 10:46:37 -0700 (PDT) (envelope-from julian@elischer.org) Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id MAA51912; Fri, 3 Aug 2001 12:41:54 -0700 (PDT) Date: Fri, 3 Aug 2001 12:41:53 -0700 (PDT) From: Julian Elischer To: Mike Smith Cc: Kenneth Wayne Culver , John Baldwin , freebsd-hackers@FreeBSD.ORG, craig , Terry Lambert , Rik van Riel Subject: Re: How to visit physical memory above 4G? In-Reply-To: <200108030352.f733q9C01482@mass.dis.org> Message-ID: 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, Mike Smith wrote: > Julian is on crack. DAC (Double Address Cycle) is a relatively recent > addition to PCI that allows 32-bit cards with 64-bit savvy logic to talk > to host memory using 64-bit target addresses. well "day 1" was an exageration, but my 1995 PCI stuff already includes it. Crack? no.. optimism, maybe.. > Older systems used a scatter-gather mechanism to present a virtualised > view of the system's physical address space to the PCI bus (typically > you'll see this in Alpha systems). To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message