Downgrade from Jetpack 6 to Jetpack 5 on Jetson Orin Nano Dev Board

Issue Overview

Users of the Nvidia Jetson Orin Nano Developer Kit have reported difficulties in downgrading from Jetpack 6 to Jetpack 5. Symptoms include failure to execute the downgrade process, particularly when using the l4t_initrd_flash.sh script, which results in errors such as "Invalid target board – jetson-orin-nano-devkit." The issue arises after upgrading to Jetpack 6, which also upgrades the underlying Ubuntu version from 20.04 to 22.04, a change that some users do not require for their projects. Users have noted that they have spent considerable time attempting to downgrade without success, often due to a lack of clear instructions and potential compatibility issues related to UEFI firmware changes. The problem significantly impacts user experience by preventing access to necessary software environments, especially for those relying on specific versions of ROS (Robot Operating System) that are compatible only with Ubuntu 20.04.

Possible Causes

• Hardware Incompatibilities: The change in UEFI firmware may cause compatibility issues with downgrade procedures.
• Software Bugs: Bugs in the downgrade scripts or mismatches between Jetpack versions could lead to errors during the flashing process.
• Configuration Errors: Incorrect parameters or commands used during the downgrade attempt can result in failures.
• Driver Issues: Conflicts between drivers installed with Jetpack 6 and those required for Jetpack 5 may prevent successful operation.
• Environmental Factors: Power supply issues or overheating could affect the flashing process.
• User Errors: Misunderstanding of required packages or procedures might lead users to incorrectly execute commands.

Troubleshooting Steps, Solutions & Fixes

1. Preparation for Downgrade:

   • Ensure you have the correct version of Jetpack and Ubuntu images downloaded:
     • Jetson Linux R35.5.0
     • Tegra Linux Sample Root Filesystem

2. Using the Correct Commands:

   • Run the command within the Linux_for_Tegra directory to avoid "invalid target board" errors:

     sudo ./nvidia/nvidia_sdk/JetPack_5.1.3_Linux_JETSON_ORIN_NANO_TARGETS/Linux_for_Tegra/tools/kernel_flash/l4t_initrd_flash.sh --external-device sda1 -c tools/kernel_flash/flash_l4t_external.xml -p "-T 62333952 -c bootloader/t186ref/cfg/flash_t234_qspi.xml" --showlogs --network usb0 jetson-orin-nano-devkit internal
     

3. Debugging Errors:

   • If you encounter an "Invalid target board" error, verify that you are using the correct board identifier and that your board is in recovery mode.
   • Check your command syntax and ensure all paths are correct.

4. Required Hardware:

   • A USB to UART lead is not necessary unless debugging is required; it is primarily for debug purposes.

5. Re-flashing Considerations:

   • If downgrading fails, consider re-flashing with Jetpack 5 directly using the SDK Manager, ensuring that your board is detected properly.

6. Best Practices:

   • Always back up your data before attempting a downgrade or flash.
   • Follow official Nvidia documentation closely for any updates regarding downgrading processes.

7. Future Considerations:

   • Request Nvidia to simplify the downgrade process in future SDK updates and clarify the implications of upgrading on their setup guides.

8. Unresolved Issues:

   • Users have raised questions about whether it will be possible to expose GPUs in Docker containers running Ubuntu 20.04 under Jetpack 6, indicating a need for further exploration into compatibility issues between different NVCC versions.

By following these troubleshooting steps and solutions, users should be able to navigate the complexities of downgrading from Jetpack 6 to Jetpack 5 on their Nvidia Jetson Orin Nano Developer Kit effectively.