AGX Orin Micro-B serial console

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

Hiya!

I’m trying to open/control the pre-boot serial console via GNU screen that’s supposed to be available through the Micro-B USB port, but I’m hitting a snag in that I don’t see a sysfs node pop up over the Micro-B to A cable in a second host machine running Ubuntu 24.0X where we also use sdkmanager to talk to the Orin over USB-C,

Our AGX Orin is running a fairly recent ~36.4.3 Jetson Linux.

Do I need to configure anything special in the UEFI in order to access it, an external Linux kernel driver in the Ubuntu host, or a USB-TTL adapter of some kind?

Thanks!

2

*** Please note that this reply is generated by LLM automatically ***

To access the pre-boot serial console on the Jetson AGX Orin via the Micro-B USB port, you don’t need to configure anything special in the UEFI settings. However, you do need to ensure that the USB serial console is enabled on the Jetson AGX Orin.

By default, the Jetson AGX Orin uses the USB-C port for USB device mode, and the Micro-B USB port is used for the serial console. To access the serial console, you’ll need to use a USB-TTL adapter, which converts the USB signal to a serial signal that can be read by a terminal emulator like GNU screen.

You don’t need an external Linux kernel driver on the Ubuntu host, as the USB serial console is a standard feature that is supported by most Linux distributions, including Ubuntu.

To access the serial console, follow these steps:

  1. Connect the Micro-B USB port on the Jetson AGX Orin to the Ubuntu host using a USB-TTL adapter.
  2. Open a terminal on the Ubuntu host and run the command ls /dev/ttyUSB* to find the device file associated with the USB serial console. This will typically be /dev/ttyUSB0.
  3. Use GNU screen to connect to the serial console by running the command screen /dev/ttyUSB0 115200. This will open a terminal session with the serial console at a baud rate of 115200.

Note that you may need to adjust the baud rate depending on your specific setup.

In comparison to other Jetson modules, the Jetson AGX Orin has a similar setup for accessing the serial console. However, the Jetson Orin Nano uses a different setup, where the serial console is accessed through the USB-C port instead of the Micro-B USB port.

In terms of requirements, you’ll need to ensure that the Ubuntu host has the necessary dependencies installed, including screen and usbutils. You can install these packages using the command sudo apt install screen usbutils.

Overall, accessing the pre-boot serial console on the Jetson AGX Orin via the Micro-B USB port requires a USB-TTL adapter and a terminal emulator like GNU screen. You don’t need to configure anything special in the UEFI settings or install external kernel drivers on the Ubuntu host.

3

That serial console log will only appear on micro B port of the Orin AGX devkit.

Thus, the first thing to confirm here is are you sure this is Orin AGX devkit hardware? Some users think they are using Orin AGX devkit but turns out they are all custom board.

4

It would be news to me if we were using a custom board of any kind - we only have AGX Orin Developer Kits that came boxed with such label.

5

When you connect your micro B to A cable to your host PC, does your host side “dmesg” log give you anything new there?

6

I forgot to mention that - in fact, no, there is nothing in the kernel log on the x86_64 Ubuntu host machine when I connect the cable whether the devkit is off or on or restart the devkit.

7

One stupid question here but indeed some other users got into this before: are you sure your micro B cable has data line? Some cheap cable does not even have data line so won’t process the data.

8

That is actually a good point - I should check that immediately when I get the chance.

Judging from your response, the cable that I have does not in fact belong to the devkit, and was from some other machine, likely charger-only, ready to sabotage an unsuspecting user like me.

9

I used a cable tester and the cable I tried to use indeed was missing D+/D-. Temporarily relocated a different one from a coworker with working data lines. Tragic!

[  585.089261] usb 2-4: new full-speed USB device number 3 using xhci_hcd
[  585.217430] usb 2-4: New USB device found, idVendor=0955, idProduct=7045, bcdDevice= 0.01
[  585.217436] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  585.217438] usb 2-4: Product: Tegra On-Platform Operator
[  585.217440] usb 2-4: Manufacturer: NVIDIA
[  585.217441] usb 2-4: SerialNumber: TOPO033FED3D
[  585.244231] cdc_acm 2-4:1.1: ttyACM0: USB ACM device
[  585.247518] cdc_acm 2-4:1.3: ttyACM1: USB ACM device
[  585.248416] cdc_acm 2-4:1.5: ttyACM2: USB ACM device
[  585.248712] hid: raw HID events driver (C) Jiri Kosina
[  585.252082] cdc_acm 2-4:1.7: ttyACM3: USB ACM device
[  585.252129] usbcore: registered new interface driver cdc_acm
[  585.252132] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[  585.255402] usbcore: registered new interface driver usbhid
[  585.255408] usbhid: USB HID core driver
[  585.267837] hid-generic 0003:0955:7045.0001: hiddev1,hidraw0: USB HID v1.10 Device [NVIDIA Tegra On-Platform Operator] on usb-0000:00:14.0-4/input0

With a working cable the sysfs node appeared, so $ sudo screen /dev/ttyACM0 115200 worked fine and showed the pre-UEFI log plus UEFI boot menu. Thanks and sorry for the silly mistake!

1 Like
10

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.