Jetson Orin Nano Boot Failure After Adding Systemd Service

Issue Overview

The Jetson Orin Nano development board is experiencing a boot failure after the user added a systemd service to run a Python script for opening a TCP server on startup. The specific symptoms include:

• Initial attempt to boot over PXE
• Black screen after selecting to boot from SD card in the boot manager
• Complete inability to boot into the operating system

This issue occurred immediately after the user added the systemd service and rebooted the device. The problem prevents access to the Jetson, rendering it unusable and potentially causing significant disruption to development or production workflows.

Possible Causes

1. Incorrect systemd service configuration: The newly added service may contain errors in its configuration, preventing the system from booting properly.

2. Python script errors: The TCP server script might have critical errors or dependencies that are causing the boot process to hang.

3. Permissions issues: Incorrect user permissions in the service file or for the Python script could lead to boot failures.

4. Resource conflicts: The TCP server might be attempting to use resources that conflict with essential system processes during boot.

5. Corrupted boot files: The process of adding the service and rebooting might have inadvertently corrupted critical boot files on the SD card.

6. Hardware issues: While less likely, the reboot process could have coincided with or triggered a hardware problem.

Troubleshooting Steps, Solutions & Fixes

1. Connect via UART:

   • Connect the Jetson Orin Nano to a computer using a UART (Universal Asynchronous Receiver/Transmitter) connection.
   • This may allow you to access the console and see boot messages, helping diagnose the issue.

2. Boot into recovery mode:

   • If possible, try to boot the Jetson into recovery mode.
   • This can often be done by holding specific buttons during power-on, but refer to NVIDIA’s documentation for the exact procedure for the Orin Nano.

3. Remove the problematic service:

   • If you can access the file system (e.g., by mounting the SD card on another computer), locate and remove the newly added service file.
   • The service file is likely located in /etc/systemd/system/tcp-server.service.

4. Check and correct the service file:

   • If you can access the service file, review it for any obvious errors:
     • Ensure all paths are correct
     • Verify the user specified exists and has appropriate permissions
     • Check that the Python script exists and is executable

5. Examine log files:

   • If you can access the file system, check the log files specified in the service file:
     • /var/log/tcp-server.log
     • /var/log/tcp-server-error.log
   • These may contain error messages that could help identify the issue.

6. Disable the service:

   • If you can access a command line (via UART or recovery mode), try disabling the service:

     sudo systemctl disable tcp-server.service
     

7. Verify SD card integrity:

   • If possible, check the SD card for errors using another computer.
   • Consider creating a backup of the SD card before attempting any fixes.

8. Reflash the Jetson:

   • As a last resort, reflash the Jetson Orin Nano with the original image.
   • While this will resolve the boot issue, it will also erase all data and configurations on the device.

9. Gradual service implementation:

   • After resolving the issue, implement the TCP server service gradually:
     • Start by testing the Python script manually
     • Create a simple service that just logs a message
     • Incrementally add complexity to the service, testing after each change

10. Use a startup script instead:

    • As an alternative to a systemd service, consider using a startup script in /etc/rc.local to run your Python script.
    • This can be easier to debug and less likely to cause boot failures.

Remember to always create backups before making system-level changes, and test new services thoroughly before implementing them on a production device.