Disable logging from printing on the serial console

[Abhishek Chr]

I am using the latest Armbian Noble image (version 6.6.8) on my Banana Pi CM4. For my application, I am utilizing the Linux UART (/dev/ttyAML0), which is currently printing dmesg logs on this port. Is there a way I can disable dmesg debug logging and exclusively use /dev/ttyAML0 for my application?

 

Thanks.

[gmc2000]

The linux kernel has a command line option that sets the device to use as console. I believe it is possible to change the kernel command line by editing /boot/extlinux/extlinux.conf. Mine has 'console=ttyS02,1500000' in it, which is a serial console. Removing that should at least stop the kernel from printing messages to that serial port. There probably is a better way to configure this (I don't even know if editing extlinux.conf will do the trick). I see armbian-config documentation mentions a 'bootenv' option under 'system', but I don't see that when I run armbian-config on my board.

 

Apart from the kernel, there is likely also a login session configured to run on the serial port. You need to disable that separately:

 

When I `systemctl | grep getty` I can see there's a service running with the name 'serial-getty@ttyS2.service', disabling that should stop the serial logon console.

 

systemctl disable serial-getty@ttyS2.service

 

[gmc2000]

Btw, there is an option 'Stop low-level messages on console' under 'System' in armbian-config. I don't know what that does exactly, but worth a try?