Subject: Re: Another changer, another changer problem
To: NetBSD-current Discussion List <current-users@netbsd.org>
From: David Maxwell <david@fundy.ca>
List: current-users
Date: 10/07/1998 22:32:28
On Wed, Oct 07, 1998 at 05:08:57PM -0400, Greg A. Woods wrote:
> Whoa!  We're definitely not talking about the way Solaris does it!
> (except perhaps as a fundamentally flawed example)

Yes, I was simply refering to the capability to say 'No, I know I
built the kernel with ne0 on IRQ 10, but that card blew up, my
replacement card doesn't do IRQ 10, it does 2/9, and I don't have
kernel sources on this machine. (And If I did, I want the system
back up faster than if I have to rebuild a kernel just now.) Change
ne0 on irq10 -> ne0 on irq9'

That shouldn't be that big a deal, unless there are a lot of ties
in the kernel build I'm not aware of. If I build a kernel with the
above, and rebuild with a different IRQ, will I have two kernels
with 1 byte of difference between them?

> The FreeBSD run-time device configuration system is merely a way of
> over-riding the probe information between the time the probes are done
> and the devices are attached.  I'm not certain it currently offers a way
> to wire down device devices in the way we're talking about, but that's
> an obvious extension of the mechanism.

I'm talking about changing them even before probing. I can see lots of 
snags in sticking that process in mid-boot.

> Of course if you're running decent hardware where you can give the the
> PROM some idea of where the console should point, and assuming you're

PROM's not needed, as long as your bootblocks are intact. If your disk
is gone, I wouldn't be counting on the PROMs doing much good to help
you reinstall the disk...

(Yeah yeah, boot le0, rarp, tftp, rarp, bootparamd, nfs, kernel,
disklabel.... I know, but I don't have the patience to try that
remotely.)

> This is, of course, all blue-sky dreaming at the moment (though I will
> note that there are existing systems where a reboot will redirect the
> console to the user's current tty).

Which of course begs the question.... How do you get the damn console
back where it belongs afterwards?? I often run into Suns that have
/dev/console -> /dev/random_tty

-- 
David Maxwell, david@vex.net|david@maxwell.net --> Mastery of UNIX, like
mastery of language, offers real freedom. The price of freedom is always dear,
but there's no substitute. Personally, I'd rather pay for my freedom than live
in a bitmapped, pop-up-happy dungeon like NT. - Thomas Scoville