“local variable ‘bpmp_dtb’ referenced before assignment” error in /tegraflash_impl_t234.py

Issue Overview

Users of the Nvidia Jetson Orin Nano Dev Kit are encountering an error message when attempting to configure the pinmux using new .dtsi files. The specific error is an UnboundLocalError, indicating that the local variable bpmp_dtb is referenced before it has been assigned a value. This issue arises during the flashing process, specifically when executing the script located at /Linux_for_Tegra/bootloader/tegraflash_impl_t234.py.

Symptoms

• The error message displayed is:

  UnboundLocalError: local variable 'bpmp_dtb' referenced before assignment
  

• The issue occurs during the execution of the flashing command.

Context

• The problem manifests when users are following the official Nvidia documentation for generating pinmux .dtsi files.
• Users have reported this issue consistently when trying to flash their devices after modifying or creating new .dtsi files.

Hardware and Software Specifications

• Device: Nvidia Jetson Orin Nano Dev Kit
• Operating System: Linux for Tegra (specific version not detailed)

Impact

The error prevents users from successfully flashing their devices, which can hinder development and testing efforts. Users are unable to proceed with configuring their hardware as intended.

Possible Causes

• Hardware Incompatibilities or Defects: If there are hardware issues with the Jetson Orin Nano, it may lead to unexpected errors during flashing.

• Software Bugs or Conflicts: The script /tegraflash_impl_t234.py may contain bugs that lead to this error under certain conditions.

• Configuration Errors: Incorrectly formatted or incompatible .dtsi files could cause the script to fail.

• Driver Issues: Outdated or incompatible drivers may lead to conflicts during the flashing process.

• User Errors or Misconfigurations: Errors in the command syntax or parameters passed during the flashing process could trigger this issue.

Troubleshooting Steps, Solutions & Fixes

1. Verify Flash Command Syntax:

   • Ensure that the flash command is correctly formatted as per Nvidia’s documentation.
   • Example of a correct command:

     sudo ./flash.sh -p "your_parameters" -c "your_configuration"
     

2. Check for Custom Modifications:

   • Review any custom modifications made inside the Linux_for_Tegra BSP directory. Reverting to original settings may resolve conflicts.

3. Examine .dtsi Files:

   • Double-check the syntax and contents of your .dtsi files for any errors or incompatibilities.

4. Gather System Information:

   • Run diagnostic commands to gather information about your system configuration and logs:

     cat /var/log/syslog
     dmesg | grep tegra
     

5. Test with Default Configuration:

   • Attempt to flash with default configurations and original .dtsi files to isolate whether the issue stems from recent changes.

6. Update Drivers and Firmware:

   • Ensure that all drivers and firmware are up-to-date according to Nvidia’s latest releases.

7. Consult Documentation:

   • Refer back to Nvidia’s official guides for any updates or corrections regarding the flashing process:
     • Jetson Module Adaptation and Bring Up
     • Quick Start Guide

8. Seek Community Support:

   • If issues persist, consider posting detailed logs and descriptions on forums dedicated to Nvidia Jetson development for community assistance.

Recommended Approach

Multiple users have found success by ensuring that their flash command syntax matches exactly what is provided in Nvidia’s documentation, particularly regarding parameters passed to -p and -c. Always include quotation marks around parameters as needed.

Unresolved Aspects

Further investigation may be required into specific versions of the software being used, as well as potential bugs in the script itself that could be contributing to this error.