Re: printing boot probe messages

On Sat, Dec 22, 2007 at 12:49:41PM -0500, Chuck Robey wrote:
TCSH-april:root:/home/chuckr:#105-12:23>conscontrol
Configured: dcons
Available: dcons,gdb
Muting: off

If you use the "list" parameter to conscontrol, the same printout results. I
*think* you might be saying that I should see something dealing with
consolectl, nothing resu;ting even from man -k consolectl. I did find the
file /dev/consolectl, but I can't figure out the use of it.

conscontrol(8) output of configured/available devices simply parses the
kern.console sysctl variable. Everything after the "/" is considered an
available device for console output, and everything prior is considered
a working/used console.

So, based on the output of the command you ran, I'd say all of your
console messages (the ones you're looking for) are going to dcons.

I had absolutely no idea what "dcons" was until I man'd it. It appears
to be a basic I/O driver that allows other drivers (or busses) to attach
to it. When used as a console device, all kernel messages end up going
into that buffer.

Therefore, you appear to have some settings in your kernel configuration
which are inducing the behaviour you're experiencing.

A RELENG_6 box with serial console enabled (/boot.config contains -Dh)
and "options GDB" (but no dcons device) enabled in the kernel shows
this:

eos# conscontrol
Configured: ttyd0,consolectl
Available: ttyd0,consolectl
Muting: off
eos# sysctl kern.console
kern.console: ttyd0,consolectl,/ttyd0,consolectl,

A RELENG_7 box without serial console (just VGA), and "options GDB" in
the kernel shows this:

icarus# conscontrol
Configured: consolectl
Available: consolectl,gdb,ttyd0
Muting: off
icarus# sysctl kern.console
kern.console: consolectl,/consolectl,gdb,ttyd0,

Hmmm, I found a hint on an old email, hinting that the command "conscontrol
should have been used to add a console.

conscontrol(8) lets you adjust which devices kernel messages go to. You
can't just pick "any device in /dev". It doesn't work that way.

I just tried using the ctl-alt-f1
combo to get onto ttyv0. I did a tty, this proved I was in fact on ttyv0, so
i tried to do a "conscontrol add /dev/ttyv0, but what came back was "device
not configured". I think I'm close here, so what should my console device be?

No, you can't do this. Your available console devices are listed when
you do `conscontrol' from the command line. In your case right now,
your available consoles are either dcons (which you're already using) or
gdb.

Based on what I can figure out, your kernel configuration is very likely
missing the inclusion of the syscons(4) driver, which is what drives VGA
output. Although, the fact that you can switch virtual VGA consoles via
Control-Alt-Fx seems to indicate you have a working VGA console somehow.

I think it would be benefitial to see your kernel configuration, the
contents of /boot/loader.conf, and /boot.config if you have one.

--
| Jeremy Chadwick jdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |

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