Jetson AGX Orin device tree location

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

Hi,

I have been looking into dts files for Jetson AGX Orin Developer kit for a while. Iintend to modify the device tree but am having difficulty locating the exact folder where the base device tree resides. From flash log it seems the dtb file being loaded is p3701-0005-nv.dtb. But I would like to know where this gets decided. From the config file used at the time of flash it seems a differnet dtb file gets loaded as I get the dtb file in /boot/dtb as p3701-0000-nv.dtb. So, I would like to know if I am looking at the right dtb file. Particularly, where does it get decided if the dtb has to be changed. Why would it pick p3701-0000 for the developer board?

2

Hello,

Thanks for visiting the NVIDIA Developer Forums.
To ensure better visibility and support, I’ve moved your post to the Jetson category where it’s more appropriate

Cheers,
Tom

1 Like
4

Hi @aleena.johns ,

I hope you are doing well.

Regarding your questions:

  1. The device tree file sources can be found under: Linux_for_Tegra/source/hardware/nvidia/t23x/nv-public/nv-platform/.

  2. The device tree being used is defined by the machine configuration file used for flashing. For example, machine configuration file jetson-agx-orin-devkit.conf defines the DTB here:

DTB_FILE=tegra234-p3737-0000+p3701-0000-nv.dtb;

If you are customizing the DTB, after compiling you need to copy the new DTB file to: Linux_for_Tegra/kernel/dtb to install.

Let me know if this helps.

Best regards,
Nico
Embedded Software Engineer at ProventusNova

6

Hi aleena.johns,

Are you using the devkit or custom board for AGX Orin?
What’s the Jetpack version in use?

Please refer to DTB Support for the workflow about how we load DTB.
It depends on if you’ve specified FDT entry in extlinux.conf.

9

Hi nico.morua,

Regarding the modification to dtb file, after modifying the dtb and placing it in kernel/dtb will not automatically let the board pick up this dtb file. For that the L4T configuration is to be modified and set to kernel partition. Follow the steps here for the same UEFI Adaptation — NVIDIA Jetson Linux Developer Guide 1 documentation . By default, the it would be extlinux which will have to be changed for the modified dtb to be used. Or you can specify the path to your modified dtb file using FDT and the specified dtb will be used. This is what worked for me.

10

Thanks for your response. My issue was a build script being used which redefined the wrong board sku resulting in a different dtb file being picked to the /boot/dtb directory but the board used the right sku dtb. Hence the confusion. It has been resolved.

12

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.