NVIDIA Jetson AGX Thor - Accessing the Board via Serial Console
 | The NVIDIA Jetson AGX Thor documentation from RidgeRun is presently being developed. |
Serial Console Access on Jetson AGX Thor
The Jetson AGX Thor Developer Kit supports serial console access through its USB Type-C port. This method allows low-level interaction with the board, including early boot logs, UEFI menu access, and Linux shell login—especially useful for debugging, flashing, and headless development.
Unlike earlier Jetson platforms, Thor does not include a Micro-USB port. Only the USB-C debug port supports serial communication.
Connecting via USB-C
Use a USB-C to USB-A cable (or USB-C to USB-C if your host supports it), and connect it to the port labeled as the debug USB-C in Figure 1. You will have to remove the magnetic lid to reach it.
Once connected to a Linux host, a serial device will appear—typically as /dev/ttyACM0. You can confirm this with:
ls /dev/ttyACM*
This connection works even if the board is not powered on, as long as it's connected to a valid power source.
Using Minicom
Install Minicom on your host (Ubuntu):
sudo apt install minicom
Launch Minicom using the appropriate device node:
sudo minicom -D /dev/ttyACM0 -8 -b 115200
If you encounter a "permission denied" error, check group ownership:
ls -l /dev/ttyACM*
You’ll typically see:
crw-rw---- 1 root dialout 188, 0 /dev/ttyACM0
Add your user to the dialout group to avoid needing sudo in the future:
sudo usermod -aG dialout $USER
Log out and back in for the change to take effect.
Expected Output
Once connected, Minicom will show logs from the bootloader and Linux kernel. This includes early firmware (MB1, UEFI), bootloader messages, and the kernel boot log, up to a login promt. Example:
[0000.096] I> MB1 (version: 0.23.0.1-t264-75019003-35ec65c7)
[0000.096] C> Boot-mode : Coldboot
[0000.096] C> MB1 last_boot_error: 0x0
...
[ OK ] Finished user-runtime-dir@120.serv…er Runtime Directory /run/user/120.
Starting user@120.service - User Manager for UID 120...
[ OK ] Started user@120.service - User Manager for UID 120.
[ OK ] Started session-c1.scope - Session c1 of User gnome-initial-setup.
Ubuntu 24.04.3 LTS localhost.localdomain ttyUTC0
localhost login:
You can interact with the UEFI menu or log in directly to Ubuntu via the serial console.
Additional Tips
Use Ctrl+A Z in Minicom to access the command menu (e.g., to exit or log output).
You can script serial interactions using tools like screen, picocom, or Python's pyserial.
Serial console is particularly useful if networking is not yet configured or GUI access is unavailable.