if you ever feel the need to know the SoM pin to tty in software on hopefully all 260-Pin SO-DIMM Jetsons.

jetson_tty.md

Checked for NANO, TX2 NX, XAVIER NX, ORIN NANO, ORIN NX

Services and Configs

systemctl status nvgetty.service:

UART	Xavier NX	Orin Nano/NX	Nano	TX2 NX
Getty Service	ttyTHS0	ttyTHS0	ttyTHS0	ttyTHS0

kernel boot args in /boot/extlinux/extlinux (may be different in JP version): Important here is: console=ttyTCU0,115200n8 console=tty0

    APPEND ${cbootargs} root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyTCU0,115200n8 console=tty0 [ANNND SO ONNNN]

Several Devicetree configs. TX2 NX for example:

	chosen {
		board-has-eeprom;
		bootargs ="console=ttyS0,115200";
		stdout-path = &uarta;
		nvidia,tegra-joint_xpu_rail;
	};

Overview

UART	Pins TX, RX, RTS, CTS	Xavier NX	Orin Nano/NX	Nano	TX2 NX
UART 2 Debug	236, 238	/dev/ttyTHS0	/dev/ttyTHS0	/dev/ttyTHS1	/dev/ttyTHS2
UART 0	99, 101, 103, 105	/dev/ttyTHS1	/dev/ttyTHS1	/dev/ttyTHS2	/dev/ttyTHS1
UART 1	203, 205, 207, 209	/dev/ttyTCU0	/dev/ttyTCU0	/dev/ttyS0	/dev/ttyS0

Xavier NX (Tested on JP5)

UART	Pins TX, RX, RTS, CTS	Note	Software TTY
UART 2 Debug	236, 238	Bootloader	/dev/ttyTHS0
UART 0	99, 101, 103, 105	Empty	/dev/ttyTHS1
UART 1	203, 205, 207, 209	Bootloader & Kernel Logs	/dev/ttyTCU0

Nano (Tested on JP4)

UART	Pins TX, RX, RTS, CTS	Note	Software TTY
UART 2 Debug	236, 238	Empty	/dev/ttyTHS1
UART 0	99, 101, 103, 105	Empty	/dev/ttyTHS2
UART 1	203, 205, 207, 209	Bootloader & Kernel Logs	/dev/ttyS0

TX2 NX (Tested on JP4)

ttyTHS2 is not enabled by default in the devicetree. Modify serial@c280000 in the DT for functionallity.

UART	Pins TX, RX, RTS, CTS	Note	Software TTY
UART 2 Debug	236, 238	Little Kernel Bootloader	/dev/ttyTHS2
UART 0	99, 101, 103, 105	Empty	/dev/ttyTHS1
UART 1	203, 205, 207, 209	Bootloader & Kernel Logs	/dev/ttyS0

Orin Nano/Orin NX (Tested on JP5)

UART	Pins TX, RX, RTS, CTS	Note	Software TTY
UART 2 Debug	236, 238	Empty	/dev/ttyTHS0
UART 0	99, 101, 103, 105	Empty	/dev/ttyTHS1
UART 1	203, 205, 207, 209	Bootloader & Kernel Logs	/dev/ttyTCU0