No kernel messages displayed during boot
Jeremy Chadwick
koitsu at FreeBSD.org
Mon Nov 19 06:47:53 PST 2007
On Mon, Nov 19, 2007 at 09:24:01AM +0100, Dmitry Karasik wrote:
> Jeremy> On Sun, Nov 18, 2007 at 08:01:59PM +0100, Dmitry Karasik wrote:
> >> I've re-run 'make installworld' and 'make installkernel' (as I had
> >> leftovers from recent buildworld), - didn't help. I've tried to power
> >> down the machine (suspecied video card trouble), I've resetted BIOS,
> >> I've even disabled com port in BIOS (because the behavior looks like
> >> booting on serial console) -- nothing, absolutely nothing changes it.
>
> Jeremy> conscontrol(8) might help here ("conscontrol list"). Also worth
> Jeremy> looking at is sysctl kern.console.
>
> Hello Jeremy,
>
> Thanks, at least this is a hint. That shows on my system:
>
> $ conscontrol list
> Configured:
> Available:
> Muting: off
Hmm, it looks as if the system doesn't have any indication of what the
local console is. I would expect to see a "consolectl" listed under
the "Configured:" section. See below for some of the output from our
systems...
> and sysctl kern.console is / (not that I know what that means).
I believe the sysctl is a comma-delimited list of what consoles are
configured and available/unused. The "/" splits what's a configured
console and what's available/unused. I bet conscontrol(8) just parses
the sysctl output, but I'd have to look at the code.
> $ conscontrol add /dev/console
> conscontrol: could not add console as a console: Device not configured
> $ conscontrol add /dev/consolectl
> conscontrol: could not add consolectl as a console: Device not configured
>
> Is that the expected behavior? What else I might try?
I'm betting that's not expected behaviour. :-) It seems to indicate
the system has no knowledge of what the system console is.
Here's some data for comparison:
Our RELENG_6 systems which use serial console, and have a /boot.config
of -S115200 -Dh on them show the following:
eos# conscontrol list
Configured: ttyd0,consolectl
Available: ttyd0,consolectl
Muting: off
eos# sysctl kern.console
kern.console: ttyd0,consolectl,/ttyd0,consolectl,
And a RELENG_7 box with serial console (same /boot.config as above):
northstar# conscontrol list
Configured: ttyd0,consolectl,gdb
Available: consolectl,gdb,ttyd0
Muting: off
northstar# sysctl kern.console
kern.console: ttyd0,consolectl,gdb,/consolectl,gdb,ttyd0,
A RELENG_7 box with no serial console (no /boot.config):
icarus# conscontrol list
Configured: consolectl
Available: consolectl,gdb,ttyd0
Muting: off
icarus# sysctl kern.console
kern.console: consolectl,/consolectl,gdb,ttyd0,
--
| 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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