Kernel Not Booting in Jetson Orin Nano

Issue Overview

Users are experiencing boot failures on the Nvidia Jetson Orin Nano after attempting to compile and replace the kernel image. The symptoms include the device powering on (indicated by a blinking fan and LED), but the connected monitor goes blank after displaying an initial boot screen. This issue arises specifically after users have replaced the kernel image in the /boot/ directory and modified the extlinux.conf file to include backup entries. The problem occurs consistently, leading to significant frustration as users are unable to access their devices. The impact is severe, as it prevents users from utilizing their development boards for projects, effectively rendering them unusable until resolved.

Possible Causes

1. Kernel Compilation Errors: Incorrect configurations during kernel compilation may lead to an incompatible or unstable kernel.
2. Configuration File Issues: Errors in modifying extlinux.conf can prevent proper booting if paths or entries are incorrect.
3. Hardware Incompatibilities: Using unsupported hardware or peripherals can lead to boot failures.
4. Driver Issues: Mismatched or missing drivers for the new kernel can cause the system to fail during boot.
5. Environmental Factors: Insufficient power supply or overheating could affect system stability during boot.
6. User Errors: Mistakes in following kernel compilation steps or improper configuration could lead to these issues.

Troubleshooting Steps, Solutions & Fixes

1. Revert to Default Kernel:

   • Remove the newly compiled kernel image from /boot/.
   • Restore the original kernel image that was working previously.

2. Check Configuration Files:

   • Review extlinux.conf for any syntax errors or incorrect paths.
   • Ensure that backup entries are correctly uncommented and pointing to valid images.

3. Use Serial Console for Logs:

   • Connect a serial console (using a TTL to USB adapter) to capture boot logs, which can provide insights into where the boot process fails.
   • Use terminal settings of 115200 8N1 for connection.

4. Rebuild Kernel:

   • Follow official Nvidia documentation for kernel compilation closely (e.g., NVIDIA Jetson Kernel Customization).
   • Use make menuconfig instead of directly editing .config files to ensure changes are preserved.

5. Test Different SD Cards or Media:

   • If using an SD card, try a different card or re-flash the current one using SDK Manager.
   • Ensure that the SD card is properly formatted and contains a valid image.

6. Update QSPI Bootloader:

   • If using an SD card image, ensure that the QSPI bootloader is updated using SDK Manager, as this is crucial for proper booting from external media.

7. Check Power Supply and Connections:

   • Verify that the power supply is adequate and all connections (power, HDMI, etc.) are secure.

8. Consult Community and Documentation:

   • Engage with community forums for additional insights and troubleshooting steps shared by other users who faced similar issues.

9. Best Practices for Future Prevention:

   • Always keep a backup of working kernel images before making changes.
   • Document all steps taken during kernel compilation and configuration changes for easier rollback if issues arise.

10. Potential Fixes for Specific Errors:

    • If encountering specific error messages during boot, search Nvidia forums for similar issues and recommended fixes.

By following these structured troubleshooting steps, users should be able to diagnose and resolve boot issues related to their Nvidia Jetson Orin Nano development board effectively.