Kernel Replacement on Jetson Orin Nano

Issue Overview

Users are inquiring about the process of replacing the kernel on the Nvidia Jetson Orin Nano with a newly built version that includes modified driver codes. The context involves a user attempting to connect a 5G modem via USB-C, which requires kernel modifications as per guidance from the device vendor. The user seeks clarification on the feasibility of this replacement and requests a guide for the process.

Specific Symptoms

• User receives an error message when attempting to install drivers for a 5G modem.
• Uncertainty about whether the current kernel can be replaced without issues.
• Need for clarification on how to compile and install a custom kernel.

Context

The issue arises during development efforts to integrate a 5G modem with the Jetson Orin Nano. The user has received porting guidance that necessitates kernel modifications, prompting questions about how to proceed with replacing the kernel safely.

Hardware/Software Specifications

• Hardware: Nvidia Jetson Orin Nano, 5G modem connected via USB-C
• Software: JetPack (specific version not mentioned), Linux kernel

Frequency of Issue

This issue is not uncommon among developers working with embedded systems and custom drivers, particularly when integrating new hardware.

Impact on User Experience

The inability to replace or modify the kernel can hinder users’ ability to utilize new hardware effectively, impacting project timelines and functionality.

Possible Causes

1. Kernel Compatibility: The new kernel may not be compatible with existing modules or configurations.

   • Explanation: If there are mismatches between kernel versions and module paths, it can lead to boot failures or system instability.

2. Incorrect Installation Procedures: Users may not be following the correct steps for compiling and installing a new kernel.

   • Explanation: Deviating from standard procedures can result in errors during installation or runtime.

3. Driver Issues: The modified drivers may not function correctly with the new kernel.

   • Explanation: If drivers are not properly compiled or configured for the new kernel, they may fail to load or operate as expected.

4. Environmental Factors: Issues related to power supply or hardware connections can affect kernel behavior.

   • Explanation: Inadequate power or faulty connections can lead to unpredictable behavior during boot or operation.

Troubleshooting Steps, Solutions & Fixes

1. Compile the Kernel:

   • Follow these general steps to compile a new kernel:

     cd ~/nvidia/nvidia_sdk/JetPack_5.x_Linux_JETSON_ORIN_NANO_TARGETS/Linux_for_Tegra/sources
     make O=$TEGRA_KERNEL_OUT tegra_defconfig
     make O=$TEGRA_KERNEL_OUT -j8 Image
     make O=$TEGRA_KERNEL_OUT INSTALL_MOD_PATH=$TEGRA_MODULES_OUT modules_install
     

2. Replace Kernel Image:

   • After compiling, replace the existing kernel image in /boot:

     sudo cp $TEGRA_KERNEL_OUT/Image /boot/Image
     

3. Update extlinux.conf:

   • Modify /boot/extlinux/extlinux.conf to ensure it points to the correct kernel image:

     sudo nano /boot/extlinux/extlinux.conf
     

   • Ensure that any backup entries for previous kernels are uncommented for recovery options.

4. Check Dependencies:

   • Verify that all necessary modules are present in /lib/modules/<kernel-version>/ after replacing the kernel.

5. Boot from Recovery Mode:

   • If issues arise after replacing the kernel, boot into recovery mode and revert changes if necessary by restoring from backups.

6. Test Kernel Functionality:

   • After rebooting, test functionality by running commands like uname -r to confirm that the correct kernel is loaded and check dmesg logs for errors:

     dmesg | less
     

7. Consult Documentation and Community Resources:

   • Refer to official Nvidia documentation and community forums for additional guidance on compiling and installing kernels specific to Jetson devices.

8. Reach Out for Support:

   • If issues persist, consider reaching out to Nvidia support or community forums for assistance from other developers who may have faced similar challenges.

9. Unresolved Aspects:

   • Further investigation may be needed regarding specific modifications required for drivers related to the 5G modem.
   • Users should continue sharing their experiences in forums to refine approaches based on collective insights.

By following these troubleshooting steps, users should be able to effectively diagnose and resolve issues related to replacing the kernel on their Nvidia Jetson Orin Nano devices.