for UART-D
there’s Mux for UART-3, pin# H9, H10, which choosing WiFi/BT or UART on Jetson TX2.
for UART-A
that’s uarta for the default debug port, you’ll need modifications to treat it as normal serial port. please see-also Topic 199133 for an example to configure debug port from UART-0 to UART-1.