Hi Yanhou.LI,
Are you using the custom board for AGX Orin?
What’s your Jetpack version in use?
May I know what’s your use case and how may UART interface would you need?
For AGX Orin, there’re 5 UART interface available to be used.
You could refer to the following thread for details.
Unable to correspond to "func" and "uart_tx" - #3 by KevinFFF