Customizing UEFI Boot Order and Retry Behavior on Nvidia Jetson Orin Nano

Issue Overview

Users of the Nvidia Jetson Orin Nano custom board with Jetpack 6.0 are experiencing difficulties in customizing the UEFI boot order and retry behavior. Specifically, the issue involves:

• Inability to limit boot options to only those specified in the Device Tree (DT) overlay
• The bootloader attempting all template options instead of focusing on user-specified ones
• Lack of retry functionality for network boot options, particularly HTTP IPv4
• Unwanted attempts to boot from protocols known to fail (e.g., HTTP over IPv6, PXE over IPv4 and IPv6)
• Long boot times due to timeout periods for unsuccessful boot attempts
• The system entering the UEFI boot menu after exhausting all options, rather than retrying specified methods

This issue significantly impacts the boot process efficiency and complicates board production by requiring interactive steps to configure the boot order.

Possible Causes

1. Limited UEFI Configuration Options: The default UEFI implementation may not provide sufficient granularity for customizing boot behavior beyond simple priority changes.

2. Hardcoded Boot Sequence: The bootloader might have a hardcoded sequence that includes all possible boot options, regardless of user preferences set in the DT overlay.

3. Lack of Retry Mechanism: The current UEFI implementation may not include a built-in retry mechanism for network boot options.

4. Template-Based Boot Options: The use of a template system for boot options could be preventing the exclusion of unwanted protocols or devices.

5. Production-Oriented Design: The UEFI might be designed with a focus on flexibility for various use cases, rather than allowing for highly specific configurations needed in production environments.

Troubleshooting Steps, Solutions & Fixes

1. Modify Boot Order via Device Tree Overlay:

   • Edit the L4TConfiguration.dts file to set the DefaultBootPriority.
   • This method changes the initial boot attempt order but does not prevent other options from being tried.

2. UEFI Menu Configuration (not suitable for production):

   • Access the UEFI menu: Boot Maintenance Manager → Boot Options → Change Boot Order
   • Manually set the desired boot order.

3. Remove Unwanted Boot Devices:

   • Investigate the possibility of removing unwanted boot devices from the configuration.
   • This may require identifying and modifying the relevant configuration files or scripts that define available boot options.

4. Custom UEFI Modification (advanced):

   • As per the forum discussion, customizing the boot process to repeatedly attempt HTTP IPv4 boot or remove unwanted options requires modifying the UEFI source code.
   • Steps for UEFI source modification:
     a. Obtain the UEFI source code for the Jetson Orin Nano.
     b. Locate the boot sequence implementation.
     c. Modify the code to implement the desired retry logic for HTTP IPv4 boot.
     d. Remove or comment out the code responsible for attempting unwanted boot options.
     e. Recompile the modified UEFI source.
     f. Flash the custom UEFI to the device.

   Warning: Modifying UEFI source code is complex and can potentially brick the device if not done correctly. Proceed with caution and ensure you have a recovery method.

5. Optimize Network Timeouts:

   • If possible, adjust the timeout values for network boot attempts to reduce the overall boot time when preferred methods fail.
   • This may involve modifying network stack configurations within the UEFI implementation.

6. Implement a Custom Boot Manager:

   • Develop a custom boot manager that sits between the UEFI and the operating system.
   • This manager could implement the desired retry logic and boot option filtering.
   • Example pseudo-code for a custom boot manager:

   def custom_boot_manager():
       while True:
           if attempt_http_ipv4_boot():
               break
           time.sleep(retry_interval)
   

7. Consult Nvidia Support:

   • Reach out to Nvidia support or the Jetson developer community for potential upcoming features or undocumented methods to achieve the desired boot behavior.
   • Request the implementation of more flexible boot configuration options in future UEFI releases.

8. Alternative Boot Methods:

   • Explore alternative boot methods that might offer more control over the boot process, such as using U-Boot instead of UEFI if compatible with the Jetson Orin Nano.

Remember that the current behavior is considered "expected" by the Nvidia representative in the forum. Any modifications to the boot process should be thoroughly tested to ensure system stability and security.