Date: Fri, 31 Dec 1999 01:59:04 -0500 (EST) From: Chuck Robey <chuckr@picnic.mat.net> To: Brian Fundakowski Feldman <green@FreeBSD.org> Cc: FreeBSD-current@FreeBSD.org Subject: Re: multiple cd devices Message-ID: <Pine.BSF.4.21.9912310152050.2014-100000@picnic.mat.net> In-Reply-To: <Pine.BSF.4.10.9912310141580.4996-100000@green.dyndns.org>
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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. > > ---------------------------------------------------------------------------- Chuck Robey | Interests include C & Java programming, New Year's Resolution: I | electronics, communications, and will not sphroxify gullible| signal processing. people into looking up | I run picnic.mat.net: FreeBSD-current(i386) and fictitious words in the | jaunt.mat.net : FreeBSD-current(Alpha)| dictionary. | ---------------------------------------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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