Custom DTS File Location for Nvidia Jetson Orin Nano Customization

Issue Overview

Users are seeking guidance on customizing the Device Tree Source (DTS) file for a custom Nvidia Jetson Orin Nano System on Module (SOM) with a custom carrier board. The main challenges include:

• Identifying the correct DTS file for customization
• Locating the source code for the DTS file within the Jetson Linux source package
• Understanding the process of customizing the DTS file for their specific hardware configuration

The issue arises during the development and customization phase, potentially impacting the ability to properly configure and utilize the custom hardware setup.

Possible Causes

1. Lack of familiarity with Jetson Linux file structure: Users may be unfamiliar with the organization of the Jetson Linux source code, making it difficult to locate specific files.

2. Confusion about Jetson product naming conventions: The various SKUs and product names in the Jetson ecosystem can be confusing, leading to uncertainty about which files correspond to specific hardware.

3. Incomplete documentation: There might be gaps in the official documentation regarding the customization process for specific Jetson models.

4. Version-specific differences: Different JetPack or Jetson Linux versions may have slight variations in file locations or naming conventions.

Troubleshooting Steps, Solutions & Fixes

1. Identify the correct JetPack version:

   • Ensure you’re using Jetson Linux r36.2 (JetPack 5.1.1).
   • Always specify the JetPack version when seeking assistance, as file locations and processes may vary between versions.

2. Determine the correct SKU and DTB file:

   • Check the host-side flash log to identify your module’s SKU and the corresponding DTB file.
   • For the custom Orin Nano SOM mentioned, the DTB file is: kernel_tegra234-p3768-0000+p3767-0005-nv.dtb

3. Download the Jetson Linux source code:

   • Visit the official Nvidia Developer website: https://developer.nvidia.com/embedded/jetson-linux-r362
   • Download the source code package for Jetson Linux r36.2

4. Locate the DTS file:

   • Navigate to the kernel source directory in the downloaded package.
   • Find the file named tegra234-p3768-0000+p3767-0005-nv.dts
   • This is the source file you need to modify for customization.

5. Customize the DTS file:

   • Open the tegra234-p3768-0000+p3767-0005-nv.dts file in a text editor.
   • Make the necessary changes to reflect your custom carrier board configuration.
   • Common customizations include:
     • Modifying pin configurations
     • Adjusting clock settings
     • Enabling or disabling specific peripherals

6. Compile the modified DTS:

   • Use the device tree compiler (dtc) to compile your modified DTS file into a DTB:

     dtc -I dts -O dtb -o custom_tegra234-p3768-0000+p3767-0005-nv.dtb tegra234-p3768-0000+p3767-0005-nv.dts
     

7. Flash the custom DTB:

   • Replace the original DTB file with your custom one in the Jetson Linux image.
   • Flash the updated image to your Orin Nano device.

8. Test and iterate:

   • Boot your Orin Nano with the custom DTB.
   • Verify that your customizations are working as expected.
   • If issues arise, review your changes and repeat the process as necessary.

9. Consult official documentation:

   • Refer to the Nvidia Jetson Linux Developer Guide for detailed information on device tree customization.
   • Check the Jetson forum for community support and additional resources.

Remember to backup your original DTS file before making modifications, and document all changes for future reference and troubleshooting.