A question about dtb files

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

In the extlinux.conf file, I specified the DTB file as kernel_tegra234-p3768-0000+p3767-0005-nv.dtb.
This results in two imx219 device tree nodes appearing in the system.
However, when I convert this DTB file to DTS using dtc,
no imx219-related information appears in the DTS file.
What could be the reason for this discrepancy?


nvidia@ubuntu:~$ cat /boot/extlinux/extlinux.conf
TIMEOUT 30
DEFAULT JetsonIO

MENU TITLE L4T boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      FDT /boot/kernel_tegra234-p3768-0000+p3767-0005-nv.dtb
      INITRD /boot/initrd
      APPEND  root=PARTUUID=28cf5784-cf99-460f-8fd3-9d77573753f3 rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 nospectre_bhb video=efifb:off console=tty0 nv-auto-config

It seems the UEFI contains a DTBO file with imx219-related configurations.
I’ve attempted the following:

  1. Added both FDT and OVERLAYS to extlinux.conf

    • When OVERLAYS is present: The specified DTBO file is used

    • When OVERLAYS is omitted: UEFI still uses its own DTBO with imx291 configurations

  2. Added only OVERLAYS to extlinux.conf

    • The DTBO file specified in OVERLAYS fails to take effect

    • UEFI persistently uses its built-in imx291 DTBO

Critical question: How can I use my custom DTBO files without reflashing with flash.sh?

4

I don’t know the answer, but there are a few common questions to start with:

  • Is it correct that you checked that the extlinux.conf file you expected is in place after boot? You need to verify that on the running system the file is the one you’ve quoted above, and has not been altered from what you expected.
  • Did you check the serial console boot log to verify this extlinux.conf was loaded?
  • Does the serial console boot log verify this device tree was used?
  • Is this a dev kit running from an SD card, or does this have either a third party carrier board or a non-SD card boot media?
  • This only applies to an Orin NX on a third party carrier board: Are security fuses burned? Only models with eMMC have security fuses (those are third party carrier boards running a commercial module instead of a dev kit).
  • Did you remove the “APPEND” line’s “${cbootargs}”?
  • What do you see from “cat /proc/cmdline”?
  • What do you see from “head -n 1 /etc/nv_tegra_release”?
  • Please attach (A) a serial console boot log, and (B) “/etc/nv_boot_control.conf”.
6

Hi user9054,

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

Where did you specify the device nodes for IMX219?

You can refer to DTB Support to know how DTB been loaded.

7

I mistook one problem, I used the Orin nano 36.3.
There’s a problem similar to mine here:
https://forums.developer.nvidia.com/t/place-custom-overlay-file-via-extlinux-conf/298287

9

It seems device tree configurations are expected if you added both FDT and OVERLAYS in exlinux.conf.
Then you can just update the device tree through the DTB file you specified without reflashing.
May I know what’s the current issue?