Deactivate serial console?

Deactivate serial console?

[Lee Revell]

We're developing a PPC440 based system for a customer who requires that
it be possible to disable/enable the serial console without a reboot.
Is this possible without hacking the kernel?

Lee

RE: Deactivate serial console?

[Howard, Marc]

"stty -F /dev/console 0" or the equivalent in code does the trick for me
but it might be implementation dependent.

Marc W. Howard

> -----Original Message-----
> From:=20
> linuxppc-embedded-bounces+marc.howard=3Dkla-tencor.com@ozlabs.or
g [mailto:linuxppc-embedded-bounces+marc.howard=3Dkla->
tencor.com@ozlabs.org] On Behalf Of Lee Revell
> Sent: Tuesday, August 22, 2006 9:19 AM
> To: ppc
> Subject: Deactivate serial console?
>=20
> We're developing a PPC440 based system for a customer who=20
> requires that
> it be possible to disable/enable the serial console without a reboot.
> Is this possible without hacking the kernel?
>=20
> Lee
>=20
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>=20

RE: Deactivate serial console?

[Lee Revell]

On Tue, 2006-08-22 at 10:46 -0700, Howard, Marc wrote:
> stty -F /dev/console 0

Thanks - so if I read the man page correctly the 0 is interpreted as 0
baud, and I would re-enable it by "stty -F /dev/console 115200"?

Lee

Re: Deactivate serial console?

[Michael Richardson]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


>>>>> "Lee" == Lee Revell <rlrevell@joe-job.com> writes:
    Lee> On Tue, 2006-08-22 at 10:46 -0700, Howard, Marc wrote:
    >> stty -F /dev/console 0

    Lee> Thanks - so if I read the man page correctly the 0 is interpreted as 0
    Lee> baud, and I would re-enable it by "stty -F /dev/console 115200"?

  Yes, and historically baud 0 meant 'hang up modem'.
  It causes DTR to drop. 

- -- 
]       ON HUMILITY: to err is human. To moo, bovine.           |  firewalls  [
]   Michael Richardson,    Xelerance Corporation, Ottawa, ON    |net architect[
] mcr@xelerance.com      http://www.sandelman.ottawa.on.ca/mcr/ |device driver[
] panic("Just another Debian GNU/Linux using, kernel hacking, security guy"); [

    "The Microsoft _Get the Facts CD_ does not work on Linux." - orospakr

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RE: Deactivate serial console?

[Lee Revell]

On Tue, 2006-08-22 at 10:46 -0700, Howard, Marc wrote:
> "stty -F /dev/console 0" or the equivalent in code does the trick for me
> but it might be implementation dependent.
> 

That works for disabling the console but now I can't re-enable it.  stty
-F /dev/console 115200 does not restore serial console access.

Lee

> Marc W. Howard
> 
> > -----Original Message-----
> > From: 
> > linuxppc-embedded-bounces+marc.howard=kla-tencor.com@ozlabs.or
> g [mailto:linuxppc-embedded-bounces+marc.howard=kla->
> tencor.com@ozlabs.org] On Behalf Of Lee Revell
> > Sent: Tuesday, August 22, 2006 9:19 AM
> > To: ppc
> > Subject: Deactivate serial console?
> > 
> > We're developing a PPC440 based system for a customer who 
> > requires that
> > it be possible to disable/enable the serial console without a reboot.
> > Is this possible without hacking the kernel?
> > 
> > Lee
> > 
> > _______________________________________________
> > Linuxppc-embedded mailing list
> > Linuxppc-embedded@ozlabs.org
> > https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> > 
> 

RE: Deactivate serial console?

[Lee Revell]

On Tue, 2006-08-22 at 13:57 -0400, Lee Revell wrote:
> On Tue, 2006-08-22 at 10:46 -0700, Howard, Marc wrote:
> > "stty -F /dev/console 0" or the equivalent in code does the trick for me
> > but it might be implementation dependent.
> > 
> 
> That works for disabling the console but now I can't re-enable it.  stty
> -F /dev/console 115200 does not restore serial console access.

OK, for the benefit of the list readers, this solution does work.
However the disable command must be issued from telnet/SSH prompt - if
issued from the a serial console, the serial console locks up and cannot
be restored without a reboot.

Lee