From owner-freebsd-hackers Fri Oct 10 01:40:03 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id BAA03001 for hackers-outgoing; Fri, 10 Oct 1997 01:40:03 -0700 (PDT) (envelope-from owner-freebsd-hackers) Received: from word.smith.net.au (word.smith.net.au [202.0.75.3]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id BAA02957 for ; Fri, 10 Oct 1997 01:39:58 -0700 (PDT) (envelope-from mike@word.smith.net.au) Received: from word.smith.net.au (localhost.smith.net.au [127.0.0.1]) by word.smith.net.au (8.8.7/8.8.5) with ESMTP id SAA01577; Fri, 10 Oct 1997 18:06:30 +0930 (CST) Message-Id: <199710100836.SAA01577@word.smith.net.au> X-Mailer: exmh version 2.0zeta 7/24/97 To: Kenneth Merry cc: mike@smith.net.au (Mike Smith), tlambert@primenet.com, sos@sos.freebsd.dk, lederer@bonn-online.com, hackers@FreeBSD.ORG, gibbs@plutotech.com Subject: Re: HP 7100i In-reply-to: Your message of "Thu, 09 Oct 1997 22:18:14 CST." <199710100418.WAA23725@pluto.plutotech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 10 Oct 1997 18:06:28 +0930 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > Mike Smith wrote... > > I was just about to mail Justin and ask if there was any documentation > > on writing code to layer under his new CAM stuff. I have a copy of the > > T13 1153Dr16 document here, and have been studying it in a little > > detail. > > > > So, is there? > > Well, nothing specifically about the FreeBSD implementation. But, > there are the CAM and CAM-3 specs: > > http://www.symbios.com/x3t10/io/t10/drafts/cam/cam-r12b.pdf > http://www.symbios.com/x3t10/io/t10/drafts/cam3/cam3r02.pdf Snarfen... > > I think the way to go, if you want to add IDE support to the > FreeBSD CAM code, is to write another transport layer to go alongside the > current transport layer. Justin can elaborate on it a little more. (I've > CCed him..) The situation is a little complicated, in that you have two fundamentally different device types hung off the same interface. For our purposes, these are ATA disks and ATAPI devices. The NetBSD approach creates an 'atapibus', off which ATAPI devices are hung. These are registered with their SCSI layer, whilst IDE disks are associated with their 'wd' driver. I'm not sure if you're suggesting that the IDE interface should be parallelled with the SCSI interface, or whether you mean that the ATAPI interface should be treated as though it were another SCSI adapter. Perhaps the CAM docco will make things clearer. mike