From owner-freebsd-current Sat May 30 03:53:15 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA28690 for freebsd-current-outgoing; Sat, 30 May 1998 03:53:15 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from tecumseh.altavista-software.com (tecumseh.altavista-software.com [205.181.164.14]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id DAA28683 for ; Sat, 30 May 1998 03:53:13 -0700 (PDT) (envelope-from matt@3am-software.com) Received: from nowin (1Cust221.tnt12.bos2.da.uu.net [208.254.158.221]) by tecumseh.altavista-software.com (8.8.5/8.8.5) with SMTP id GAA05668; Sat, 30 May 1998 06:53:02 -0400 (EDT) Message-Id: <199805301053.GAA05668@tecumseh.altavista-software.com> X-Sender: 3ampop@ranier.altavista-software.com X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0.1 Date: Sat, 30 May 1998 06:51:37 -0400 To: Doug Rabson From: Matt Thomas Subject: Re: FreeBSD/alpha status report (2) Cc: current@FreeBSD.ORG In-Reply-To: References: <199805300519.XAA02620@narnia.plutotech.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 03:16 AM 5/30/98 , Doug Rabson wrote: >I am not saying that there won't be a . I am saying that I >don't think that all the chipset implementations need to implement it. If >I do a bus_space interface, I expect that it will be something like >i386/include/bus.h. It is possible that TurboChannel and TurboLaser boxes >with multiple PCI busses might provide their own implementation rather >than the generic one. That's misguided. The point of the bus_space and bus_dma is to hide the mechanics of the underlying bus from the driver. Even if the bus is simple, the point is to abstract it (so you would have a simple abstraction). As an example, I recently moved the DEC FDDI driver to bus_dma (it already used in bus_space) which allowed me to get it running under NetBSD/pmax but only fixing coherency bugs. This means this drivers is known to work on 3 difference architectures and 3 different buses. This would be almost impossible without bus_space and bus_dma. In a week or two, I should be able to confirm it works under NetBSD/arm32. -- Matt Thomas Internet: matt@3am-software.com 3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt/ Nashua, NH Disclaimer: I disavow all knowledge of this message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message