Subject: Re: consoles
To: None <cgd@CS.cmu.edu>
From: David Seifert <seifert@sequent.com>
List: tech-kern
Date: 01/21/1997 11:28:48
In message <19468.853872567@ux2.SP.CS.CMU.EDU> you write:
> > > > The Alpha Multia/UDB has at least two somewhat independant consoles
> > > > when at the firmware level.  (TGA and the 1st rs-232 port.  I haven't
> > > > tried the 2nd rs-232 port as console yet)
> > > 
> > > And only one can be active at a time, both at the firmware level, and
> > > in NetBSD.  (the second rs-232 port cannot be used as console, FYI.)
> > > 
> > > NetBSD/alpha automatically picks the same console device that the
> > > firmware was using as its own console device.
> > 
> > I can type "man foo" on the TGA, then type "man bar" on the rs-232 console,
> > and look at two different fw man pages.  The fw seems to accept any command
> > from either console.  NetBSD seems to always pick the TGA as console.
> > There may be some fw settings that affect this.  I eventually want to find
> > some docs on the fw.
> 
> Interesting; i've never seen that behaviour.  "whatever."

> It actually _really_ surprises me that you can type to both in the
> firmware.  That has interesting security implications.  (what if
> you've set your machines up to use a graphics console, and have put a
> terminal in somebody's office for them to use.  They shouldn't be able
> to type to the firmware from that terminal...)
> 
> 
> You mentioned that this was on a Multia/UDB.  I could very well
> believe that the firmware's broken...

It might be a bug.  I find it handy, so I call it a feature.  :-)

I don't know if the Multia/UDB has a magic escape-to-firmware
sequence (often control-p), if not, you could only type fw commands
at it when at the fw level.  If the machine is setup to auto-boot,
the window would be small.

The Multia/UDB is intended to be sitting on someone's desk, not locked
away in a machine room, so would be less secure in general.

-Dave  "My other computer has multi-user firmware."  :-)