Date: Fri, 31 Dec 1999 05:25:17 -0500 (EST) From: "Chris D. Faulhaber" <jedgar@fxp.org> To: Chuck Robey <chuckr@picnic.mat.net> Cc: Brian Fundakowski Feldman <green@FreeBSD.org>, FreeBSD-current@FreeBSD.org Subject: Re: multiple cd devices Message-ID: <Pine.BSF.4.10.9912310524370.20868-100000@pawn.primelocation.net> In-Reply-To: <Pine.BSF.4.21.9912310152050.2014-100000@picnic.mat.net>
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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
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