redirecting printk to the Serial port

redirecting printk to the Serial port

[Prasad]

Hi,
	Got a silly doubt. when trying to insert one of my modules into
the kernel, its getting rebooted and unfortunately i am losing all the
debug(printk) messages.  Can i in some fashion capture all the printk's
through the serial port. (I have two linux boxes and a serial cable to
connect both of them)

Thanx in advance
Prasad.

-- 
Failure is not an option

Re: redirecting printk to the Serial port

[Martin J. Bligh]

> 	Got a silly doubt. when trying to insert one of my modules into
> the kernel, its getting rebooted and unfortunately i am losing all the
> debug(printk) messages.  Can i in some fashion capture all the printk's
> through the serial port. (I have two linux boxes and a serial cable to
> connect both of them)

See Documentation/serial-console.txt

M.

Re: redirecting printk to the Serial port

[Prasad]

I have seen the Documentation/serial-console.txt and accordingly gave the 
kernel arguments console=/dev/ttyS0,9600n8, but even after giving that i 
am not getting anything to the other end. To check if the serial 
communication was in place... i tried echo "abc" > /dev/ttyS0 and that 
worked.

Prasad.

On Sun, 2 Mar 2003, Martin J. Bligh wrote:

> > 	Got a silly doubt. when trying to insert one of my modules into
> > the kernel, its getting rebooted and unfortunately i am losing all the
> > debug(printk) messages.  Can i in some fashion capture all the printk's
> > through the serial port. (I have two linux boxes and a serial cable to
> > connect both of them)
> 
> See Documentation/serial-console.txt
> 
> M.
> 

-- 
Failure is not an option

Re: redirecting printk to the Serial port

[Zwane Mwaikambo]

On Mon, 3 Mar 2003, Prasad wrote:

> 
> 
> I have seen the Documentation/serial-console.txt and accordingly gave the 
> kernel arguments console=/dev/ttyS0,9600n8, but even after giving that i 
> am not getting anything to the other end. To check if the serial 
> communication was in place... i tried echo "abc" > /dev/ttyS0 and that 
> worked.

console=ttyS0,38400n8 console=tty1

That works on my boxes.

	Zwane
-- 
function.linuxpower.ca

Re: redirecting printk to the Serial port

[Martin J. Bligh]

--On Monday, March 03, 2003 12:58:24 +0530 Prasad <prasad_s@students.iiit.net> wrote:

> 
> 
> I have seen the Documentation/serial-console.txt and accordingly gave the 
> kernel arguments console=/dev/ttyS0,9600n8, but even after giving that i 
> am not getting anything to the other end. To check if the serial 
> communication was in place... i tried echo "abc" > /dev/ttyS0 and that 
> worked.

I use "console=ttyS0,57600n8" - no "/dev".

M.

Re: redirecting printk to the Serial port

[Prasad]

the output stopped after it printed the line "Freeing unused kernel 
memory".  How do we manage to get the printk's to the serial line after 
this. I can see the messages using 'dmesg' but am not getting them over 
the serial line.

Prasad.

On Sun, 2 Mar 2003, Martin J. Bligh wrote:

> 
> 
> --On Monday, March 03, 2003 12:58:24 +0530 Prasad <prasad_s@students.iiit.net> wrote:
> 
> > 
> > 
> > I have seen the Documentation/serial-console.txt and accordingly gave the 
> > kernel arguments console=/dev/ttyS0,9600n8, but even after giving that i 
> > am not getting anything to the other end. To check if the serial 
> > communication was in place... i tried echo "abc" > /dev/ttyS0 and that 
> > worked.
> 
> I use "console=ttyS0,57600n8" - no "/dev".
> 
> M.
> 

-- 
Failure is not an option

Re: redirecting printk to the Serial port

[Martin J. Bligh]

Make sure there's no serial stuff, etc in your init scripts that
changes speeds or anything. Other than that, not sure ... been
so long since I set it up, I forget ...

M.

--On Monday, March 03, 2003 13:09:29 +0530 Prasad <prasad_s@students.iiit.net> wrote:

> 
> the output stopped after it printed the line "Freeing unused kernel 
> memory".  How do we manage to get the printk's to the serial line after 
> this. I can see the messages using 'dmesg' but am not getting them over 
> the serial line.
> 
> Prasad.
> 
> On Sun, 2 Mar 2003, Martin J. Bligh wrote:
> 
>> 
>> 
>> --On Monday, March 03, 2003 12:58:24 +0530 Prasad <prasad_s@students.iiit.net> wrote:
>> 
>> > 
>> > 
>> > I have seen the Documentation/serial-console.txt and accordingly gave the 
>> > kernel arguments console=/dev/ttyS0,9600n8, but even after giving that i 
>> > am not getting anything to the other end. To check if the serial 
>> > communication was in place... i tried echo "abc" > /dev/ttyS0 and that 
>> > worked.
>> 
>> I use "console=ttyS0,57600n8" - no "/dev".
>> 
>> M.
>> 
> 
> -- 
> Failure is not an option
> 
> 

Re: redirecting printk to the Serial port

[Prasad]

thankx... i got the mistake... instead of giving the argument as 
console=ttyS0, i used console=/dev/ttyS0.... thank you very much

Prasad.

On Sun, 2 Mar 2003, Martin J. Bligh wrote:

> > 	Got a silly doubt. when trying to insert one of my modules into
> > the kernel, its getting rebooted and unfortunately i am losing all the
> > debug(printk) messages.  Can i in some fashion capture all the printk's
> > through the serial port. (I have two linux boxes and a serial cable to
> > connect both of them)
> 
> See Documentation/serial-console.txt
> 
> M.
> 

-- 
Failure is not an option