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Date:      Tue, 13 Jul 2004 12:05:14 -0400 (EDT)
From:      Robert Watson <rwatson@FreeBSD.org>
To:        questions@FreeBSD.org
Subject:   BIOS console redirection *and* serial console with FreeBSD
Message-ID:  <Pine.NEB.3.96L.1040713120023.66891A-100000@fledge.watson.org>

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I have access to several boxes that support "BIOS console redirection", in
which access to the BIOS and BIOS-based console I/O is redirected to a
serial port.  This is pretty neat functionality, as it allows me to
reconfigure RAID arrays, change a variety of system settings, boot
preferences, etc, via the serial console.

However, I run into a problem when I attempt to use BIOS redirection with
FreeBSD's native serial console support.  If I just configure a login
session on ttyd0, it pops up once the boot completes and appears perfectly
workable.  However, if I turn on 'console="comconsole"' in loader.conf,
the system will appear to hang or otherwise wedge rather than boot.
Currently, the boxes where I've experienced this are all remote, so I
can't report on what actually appears on the console -- however, the
systems appear to never boot.

My ideal world order would have a natural transition from BIOS console
redirection to FreeBSD's serial console, letting me configure BIOS/RAID
settings, configure loader pieces (swap kernels, set tunables, etc), then
onto the kernel serial console pieces, and finally launching a login
session on ttyd0.

Does anyone have experience with making this actually happen, or similar
experience with it not working?  I'm seeing it right now on a recent Xeon
Intel-based motherboard ("Westville"), but also on an older Intel
ServerWorkers PIII motherboard.  Is the FreeBSD loader serial code doing
something un-kosher that the BIOS redirection implementation doesn't like?
Can we make it behave better?  Or is the BIOS redirection implementation
just broken when it comes to dealing with use of the serial port by the
OS?

Thanks,

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert@fledge.watson.org      Principal Research Scientist, McAfee Research



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