The TX2/TX1 by default will output the serial debug terminal to /dev/ttyS0. As such, if this UART port is required by an application or external hardware it can be disabled. In most cases /dev/ttyS0 is assigned to UART0 on Connect Tech’s carrier boards. For additional information about the UART interface on the TX1 carriers please refer to the following KDB:
When operating the TX2/TX1 proceed as root in the terminal, and locate the ttys0.conf file in /etc/init/. When this file is found, copy it to another directory as it may be needed later if debug terminal is desired. Now remove the ttyS0.conf file from /etc/init/ and reboot, UART0 ttyS0 should now be freed from the debug serial output. You will now need to remove, “console=ttyS0,115200n8” from the “/boot/extlinux/extlinux.conf”. If you require the debug terminal you will need to add this string back to the extlinux.conf.
The extlinux.conf file is sensitive to changes if there is an error in this file the system will not boot correctly, additionally you will no longer be able to access the TX2/TX1 module through the serial debug after this modification. Please ensure when changing this file that the file is appended with only what is described in this document.