Subject: Re: Another changer, another changer problem
To: NetBSD-current Discussion List <current-users@netbsd.org>
From: Greg A. Woods <woods@most.weird.com>
List: current-users
Date: 10/05/1998 21:12:35
[ On Mon, October 5, 1998 at 14:02:57 (-0700), Bill Studenmund wrote: ]
> Subject: Re: Another changer, another changer problem
>
> Actually, the "dev" number is motherboard-specific. It's a function of how
> the motherboard (well, the host-PCI chipset) deals with configuration
> space writes and how the board is wired. When you access a configuration
> register, part of the address is decoded using a wire which is fed
> directly to the chip/card.

Hmm...  Too bad the Sys Admin Guide's configuration chapter is way out
of date and not included in /usr/share/doc.  It could discuss all these
issues, give examples of how to wire things down, and so on.

The man pages are OK, but don't really talk much about what's really
going on here.  Eg. there's only an example of wiring down a scsi device,
but no discussion of what it really means in terms of the hardware.

Similarly there's no discussion anywhere I can find of what the "dev"
parameter in a PCI driver configuration means.

Which reminds me:  the machine-independent sd(4) refers to the machine
dependent wd(4) manual page for things that may not even be described in
wd(4) when it does exist (eg. on i386).

-- 
							Greg A. Woods

+1 416 218-0098      VE3TCP      <gwoods@acm.org>      <robohack!woods>
Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com>