Subject: /dev/console as a moving target.... (was: 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: 10/07/1998 23:55:28
[ On Wed, October 7, 1998 at 22:32:28 (-0300), David Maxwell wrote: ]
> Subject: Re: Another changer, another changer problem
>
> 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

The idea once upon a time was that the console would revert to the
proper device during multi-user startup.  I.e. the temprorary console
assigned by the shutdown procedure would only remain in effect for the
PROM and for the initial boot-up sequence, and single-user mode, if
requested.  (Curt:  if you're able to reboot the system then presumably
you could mark your terminal as secure anyway, so there's nothing lost
here -- in fact this eliminates needing to mark it as secure and thus
prevents the risk that it might not be unmarked later.)

Unfortunately I think only AT&T's 3B2 version kept the code all together
and properly relinked /dev/console to /dev/syscons or whatever it was in
one of the early rc2.d startup scripts.  Of course on the 3B2 I don't
remember that you ever talked directly to the PROM, but rather only to
the second stage boot program which peeked into the filesystem to see
where /dev/console pointed.  This of course meant that if you rebooted
from a remote terminal *and* you FUBARed the root partition then you
really did have to go down to the physical console location (but with a
FUBARed / you likely had to do that anyway, unless you were lucky enough
to have an alternate root partition ready to go).

This was an extremely neat feature, esp. in the days of modems and hard
lines, but the number of vendors who could keep it all working properly
in AT&T's footsteps was very small.  I never managed to get this feature
to work properly on anything but my 3b2s.

-- 
							Greg A. Woods

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