From owner-freebsd-current Fri Dec 31 2:25:21 1999 Delivered-To: freebsd-current@freebsd.org Received: from pawn.primelocation.net (pawn.primelocation.net [205.161.238.235]) by hub.freebsd.org (Postfix) with ESMTP id F277915371; Fri, 31 Dec 1999 02:25:18 -0800 (PST) (envelope-from cdf.lists@fxp.org) Received: by pawn.primelocation.net (Postfix, from userid 1016) id CF6729B5B; Fri, 31 Dec 1999 05:25:17 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by pawn.primelocation.net (Postfix) with ESMTP id C1EF5BA0C; Fri, 31 Dec 1999 05:25:17 -0500 (EST) Date: Fri, 31 Dec 1999 05:25:17 -0500 (EST) From: "Chris D. Faulhaber" X-Sender: cdf.lists@pawn.primelocation.net To: Chuck Robey Cc: Brian Fundakowski Feldman , FreeBSD-current@FreeBSD.org Subject: Re: multiple cd devices In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 31 Dec 1999, Chuck Robey wrote: > On Fri, 31 Dec 1999, Brian Fundakowski Feldman wrote: > > > The way certain devices, like cd with its monotonically increasing counter > > where devices are probed in order and assigned device based on precedence > > and not hardwiring/controller connection, work is consistent between > > the kernel and MAKEDEV. If you have 2 cd devices, you have cd0 and cd1, > > so MAKEDEV accepts "cd2" for "two cd devices". All CD devices work > > that way. Disks don't, because there is potential for hard-wiring > > there, and will often be gaps. > > Why are "certain" devices wildly different than all other ones? I've > never encountered that kind of syntax before, and I can't see that it's > documented anywhere at all. Certainly, MAKEDEV itself (in it's > comments) treats cd* just like all the others, specifying that the number > following is a unit number, and *not* a quantity. I don't know when this > happened, but it's surely not obvious. Not one word in the handbook, > either. > > In fact, according to cd(4), you *can* specify the unit number: > > ... Prior to FreeBSD > 2.1, the first device found will be attached as cd0 the next, cd1, etc. > Beginning in FreeBSD 2.1 it is possible to specify what cd unit a device > should come on line as; refer to scsi(4) for details on kernel configura- > tion. > > That makes this odd setup even odder. Can't understand why this was done. > FWIW, bin/13768 asks the same questions. ----- Chris D. Faulhaber - jedgar@fxp.org - jedgar@FreeBSD.org -------------------------------------------------------- FreeBSD: The Power To Serve - http://www.FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message