freebsd stable - Jan 2006 - manual escape to debugger on serial console not working?

Hello,

While investigating a problem with one server i 
installed a serial console on it.
The machine has a supermicro board with console redirection enabled
on the same port, and everything seems ok, i.e. when the machine panics
i get a debugger on the serial console, but when i try to manually escape
to the debugger with BREAK (~#) i get this on the screen :
The following connections are open:
  #0 client-session (t4 r0 i0/0 o0/0 fd 4/5 cfd -1)

Manual enter to the debugger works only if i go physically  to the
keyboard and do a CTRL-ALT-ESC, 
then i get KDB: enter: manual escape to debugger on the serial console.


i have this added to my kernel conf :
options  BREAK_TO_DEBUGGER
options  KDB
options  DDB

and this in /boot/loadaer.conf :
console=comconsole

Maybe the fact that there is physically attached keyboard interferes with the 
serial console?


Regards,
Niki Denev

* Niki Denev <nike_d@cytexbg.com> [2006-01-26 10:50
+0200]:
> to the debugger with BREAK (~#) i get this on the screen :
> The following connections are open:
>   #0 client-session (t4 r0 i0/0 o0/0 fd 4/5 cfd -1)
Are you using ssh?

man ssh
   Escape Characters
     When a pseudo terminal has been requested, ssh supports a number of func-
     tions through the use of an escape character.

     A single tilde character can be sent as ~~ or by following the tilde by a
     character other than those described below.  The escape character must
     always follow a newline to be interpreted as special.  The escape charac-
     ter can be changed in configuration files using the EscapeChar configura-
     tion directive or on the command line by the -e option.

     The supported escapes (assuming the default `~') are:

     ~.      Disconnect

     ~^Z     Background ssh

     ~#      List forwarded connections

     ~&      Background ssh at logout when waiting for forwarded connection
/
             X11 sessions to terminate

     ~?      Display a list of escape characters

     ~C      Open command line (only useful for adding port forwardings using
             the -L and -R options)

     ~R      Request rekeying of the connection (only useful for SSH protocol
             version 2 and if the peer supports it)

Nicolas

-- 
http://www.rachinsky.de/nicolas

On Thursday 26 January 2006 10:54, Nicolas Rachinsky
wrote:
> * Niki Denev <nike_d@cytexbg.com> [2006-01-26 10:50 +0200]:
> > to the debugger with BREAK (~#) i get this on the screen :
> > The following connections are open:
> >   #0 client-session (t4 r0 i0/0 o0/0 fd 4/5 cfd -1)
>
> Are you using ssh?
>
> man ssh
>    Escape Characters
[...]
>
> Nicolas
Ah, this was the missing link :)
I completely forgot the part that i must
type "~~#" to actually send a BREAK.

Thank You, Nicolas!

Regards,
Niki Denev

On Jan 26, 2006, at 3:50 AM, Niki Denev wrote:
> i have this added to my kernel conf :
> options  BREAK_TO_DEBUGGER
> options  KDB
> options  DDB
I recommend ALT_BREAK_TO_DEBUGGER instead of BREAK_TO_DEBUGGER  
especially if you use cyclades terminal servers.  They send BREAK on  
power-up so if you ever have to power cycle one you're gonna halt all  
of your other boxes.