When we use NX module board’s UAR1, it can be get UART debug port message， We don’t understand why ?
please access Jetson Xavier NX Developer Kit User Guide via download center.
were you using J12, 40-pin expansion header to communicate with NX platform?
We found our problem.
In /etc/systemd/nvgetty.sh, /sbin/getty also executes on ttyTHS0.
After disabling getty, we can execute our app on UART1(ttyTHS0) without login process, thanks.