Xavier: change debug baud rate

Hi, all:

My board is xavier. The default debug baud rates is 115200.

I want to change the debug baud rates to 9600.

Can you tell me what should I do?

Thanks.

You might find this useful:
https://unix.stackexchange.com/questions/37972/set-baud-speed-for-tty
https://unix.stackexchange.com/questions/242778/what-is-the-easiest-way-to-configure-serial-port-on-linux/242814

Or on a host with the man pages installed:
man stty