SUMMARY2: Netra t1 Returns to Ok Prompt

From: Tony Fitzgerald <>
Date: Fri Aug 17 2001 - 04:29:04 EDT
I've just received this from Sun... Not as quick to respond as this list, I
might add.

Thanks again to all that responded.

SYNOPSIS:     How to disable the break signal in Solaris ?

Some PC's and Terminal Servers acting as consoles for Solaris systems send
out a break signal when they power on or off. This causes the Solaris system
to drop down to the OK prompt unintentionally. Pulling out a keyboard from a
live system and reconnecting it also causes the system to drop to the OK
prompt.  How can we prevent this ?


This can be accomplished in many ways. Some of the recommended methods are
discussed below.
1.The file /etc/default/kbd can set a variable called KEYBOARD_ABORT.
	Uncomment the line containing this variable in this file as shown
	Then run the command "kbd -i" or simply reboot the system.The "kbd
-i" command will force the system to reread the /etc/default/kbd file.
	This will permanently disable all the STOP+A and serial device break
signals on the system.
	You can re-enable the break sequence by commenting out this line in
the /etc/default/kbd file and rebooting the system or running the "kbd -i"
command again.
2.	You can enable/disable breaks with out changing any file entries
from the command line as well. 

	The " kbd -a enable" will enable the system to start accepting the
break signal and the "kbd -a disable" will disable the system from accepting
the break signal. These changes will be temporary and be in effect only till
the system reboots.
3.	You can also reboot the system after setting the following variable
in /etc/system file as shown:

	set abort_enable=0 
	This will disable all break signals on the system.
Solaris 8 introduced a new feature which gives the system the
ability to force a hanging system to halt when required, without
allowing random or spurious Breaks to cause an unintentional stop. The
new sequence to stop the system is <RETURN> <TILDE> <CONTROL B>.There
must be an interval of more than 0.5 seconds
between characters, and
the entire string must be entered in less than 5 seconds.  This is true only
with serial devices acting as consoles and not for systems with keyboards of
their own.
This feature has been backported to Solaris 2.6 and Solaris 7 as well. The
patch 105924-10 for Solaris 2.6 and 107589-02 or higher for Solaris 7 is
required to enable this feature.
To enable the alternate boot sequence, just type "kbd -a alternate" or if
this change needs to be permanent, reboot the system after uncommenting the
following line in the /etc/default/kbd file :
Note: a) Do not uncomment the KEYBOARD_ABORT=disable line while doing this.
	b) Do not set abort_enable=0 in /etc/system while doing this. 

There were two main suggestions:

1 enter a line into /etc/system set abort_enable=0
2 Have the laptop powered up with hypercom running and then
connect/disconnect the cable. This option would work just fine if I could
rely on NT staying up. So I have chosen the first option (and it works).
Which I'm told is not necessarily the best, as it prevents you from being
able to send a genuine break signal.

Thanks to all that responded. You'll be sure to hear from me soon!


Original Message:
Hi all,

I've just subscribed to this list and would like to ask my first question.

I've been appointed administrator of the above box... and am having a
problem with it returning to the ok prompt. I am connected to it via serial
port A, with a null modem cable, into an NT laptop. I'm using Hyperterm.
When I disconnect the cable, powercycle my laptop or it crashes (the latter
is normally the case), it returns to the ok prompt.

I've tried "set abort_enable=3D0=20" which was suggested on another list but
upon reboot, I'm told it ignores anything from /etc/system D0 onwards.

I haven't had much exposure to UNIX/Solaris7 (which is what I have
installed), so I guess it's going to be a very steep learning curve!

Any suggestions would be appreciated.

Received on Fri Aug 17 09:29:04 2001

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