Hi,

Is this possible to route echo output to standard file? This has to be done by default so that we don't see any echo messages on console.

This should be done only for echo with strings, if echo is acting on devices (e.g. echo 0 > /sys/class/pwm/), it should proceed as it is.

Thanks.

you can write for example exec > /tmp/logfile
and echo whatever and anything else will be put into that logfile instead of printing on the screen. (see man bash and redirection). Remember, that will not redirect error messages, you need to write exec 2>/tmp/logfile2 to catch that.

1 members found this post helpful.

Thanks, it helped to some extent. But still I see some logs like below:

During bootup:
---------------
starting pid 1423, tty '': '/etc/rc.d/rcS'
Mounting /proc and /sys
Starting the hotplug events dispatcher udevd
Synthesizing initial hotplug events
Running sysctl
Setting up networking on loopback device:

During reboot:
----------------
umount: tmpfs busy - remounted read-only
umount: can't umount /dev/pts: Invalid argument
umount: ubi1:user busy - remounted read-only
umount: can't remount rwfs read-only
umount: can't remount rwfs read-only
umount: can't umount /mnt/rwfs: Invalid argument
umount: can't umount /dev/shm: Invalid argument
umount: devtmpfs busy - remounted read-only
The system is going down NOW!
Sent SIGTERM to all processes
Sent SIGKILL to all processes

why do you need that? I do not think that can be easily solved

I am trying to disable all the logs on serial port as it will be used for printer. Tried to use "console=null", but it is having some issues, so checking other methods.

FYI. This is based on ARM project for embedded product.

Would that be "console=/dev/null" rather than "console=null" ?
And you also might try "earlycon=/dev/null".
Another possibility is "loglevel=0".

1 members found this post helpful.

I tried "console=/dev/null", no logs seen. If we do "echo Hello > /dev/ttyXYZ" no prints are coming on UART port.
Adding "earlycon=/dev/null" and "loglevel=0" didn't make any difference.

So setting console=/dev/null worked for you?

Yes, no logs are seen. So with respect to disabling logs, it is perfect.

After that I try to print something on serial port, nothing is seen. Is this sending all UART output to /dev/null?

No - it is more likely that the UART isn't configured for the right speed/start or stop bits/parity/noparity/7bit/8bit...

Yes you are right. If I invoke getty and then try, it works fine. Not sure if there are any other ways to init serial than getty.

It is the easiest way - but "stty --file=/dev/ttyXXX sane" does the same thing without initiating the login.

Thank you very much Pollard, it worked!
First I tried with "", since I didn't see echo prints on terminal, added baud rate setting as: stty -F /dev/ttymxc1 115200, then it worked!

It is my first post in forum and very happy with outcome Thanks to all!