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From: "Rodney W. Grimes" <rgrimes@GndRsh.aac.dev.com>
Message-Id: <199603122339.PAA14481@GndRsh.aac.dev.com>
Subject: Re: COMCONSOLE: a patch and a problem
To: joerg_wunsch@uriah.heep.sax.de
Date: Tue, 12 Mar 1996 15:39:08 -0800 (PST)
Cc: freebsd-current@FreeBSD.org
In-Reply-To: <199603122216.XAA05836@uriah.heep.sax.de> from "J Wunsch" at Mar 12, 96 11:16:27 pm
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> 
> As Douglas Ambrisko wrote:
> 
> >   I'll also take a look at syscons and see why it should
> > be different.
> 
> syscons uses a different tty structure for the console than for VT1.
> 
> > I'll try to put my patches together this weekend, I'm pretty tied up this
> > week.  I also want to take a look at the kernel to see if I can save
> > the last boot mode.  This way you can boot -h to get the serial port and -g
> > to get the graphics console and the kernel would remember that for the
> > next boot.
> 
> By now, -h is a toggle (btw.).
> 
> Most people would hesitate if you always write back the boot block,
> just to store a single bit in it.  Well, van Gilluwe reports bit 2 of
> the so-called ``equipment byte'' in the CMOS (offset 0x14) as
> `unused'.  Perhaps we could use it to store the serial console flag
> there? :)

Absolutely not.  Storing stuff in the CMOS by an OS is a nasty and
very risky thing to do.  It may be unused today, but that is the BIOS
writters land, and playing in that land is asking for problems down
the road.


-- 
Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
Accurate Automation Company                 Reliable computers for FreeBSD