WARNING: Test Key is used on Nvidia Jetson Orin Nano Dev Kit

Issue Overview

Users of the Nvidia Jetson Orin Nano developer kit are encountering a warning message during the boot process stating "WARNING: Test Key is used." This issue occurs after installing the OS onto an SD card following the official Nvidia tutorial. The warning appears on screen before the device boots, and in some cases, it may lead to boot failures requiring a re-flash of the SD card. This problem affects brand new Jetson Orin Nano devices and SD cards, even when using the latest SD card image from the official tutorial page.

Possible Causes

1. Default Security Configuration: The warning message is a result of the Jetson’s default security setup, which uses a NULL key (test key) for signing boot partitions.

2. Dev Kit Design: The issue is inherent to the SD card-based developer kit models, which are designed differently from eMMC models intended for commercial products.

3. Lack of BIOS: Jetson devices do not have a traditional BIOS, instead relying on partitions in QSPI memory for boot-related functions.

4. Unsigned Boot Partitions: The warning appears because the boot partitions are signed with a test key rather than a production key.

Troubleshooting Steps, Solutions & Fixes

1. Understand the Warning:

   • The "Test Key" warning is normal for SD card-based Jetson Orin Nano developer kits.
   • It does not necessarily indicate a malfunction or security breach.

2. Accept the Limitation:

   • For SD card models, there is currently no known way to disable this warning message without causing other issues.
   • The warning is part of the device’s design for development purposes.

3. Ensure Proper SD Card Flashing:

   • Double-check that you’ve followed the official Nvidia tutorial correctly.
   • Use only the latest SD card image from the official Nvidia website.

4. Handle Boot Failures:

   • If the device fails to boot, try re-flashing the SD card as a first step.
   • Ensure you’re using a high-quality, recommended SD card for better reliability.

5. Consider eMMC Models for Production:

   • If you’re planning a commercial product, consider using eMMC-based Jetson models instead of SD card-based dev kits.
   • eMMC models allow for fuse burning and permanent key setup, which can eliminate the warning message.

6. Understand Key Signing Process:

   • The boot partitions are signed with a key stored in QSPI memory.
   • Without the correct key, the boot content would be refused.

7. Note on Fuse Burning (for eMMC models only):

   • eMMC models can have security fuses burned with a secret key to remove the warning.
   • This process is irreversible and should be done carefully:

     # Example command for burning fuses (DO NOT use on SD card models)
     sudo flash.sh -k <path_to_secret_key> jetson-orin-nano-devkit mmcblk0p1
     

8. Monitor for Official Updates:

   • Keep an eye on Nvidia’s official forums and documentation for any future updates or solutions specific to this issue.

9. Consult Nvidia Support:

   • If the boot failures persist or you need further clarification, consider reaching out to Nvidia’s official support channels.

Remember that this warning message is a normal part of the SD card-based Jetson Orin Nano developer kit’s operation and does not typically affect its functionality for development purposes.