OVERLAYS mechanism cannot be used to dynamically add the camera's dtbo on JP6.0

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
1

As mentioned in this link,I successfully added the camera’s dtbo dynamically under the Jetpack 6.0 system by adding the FDT and OVERLAYS fields in the /boot/extlinux/extlinux.conf file.

However, when I tried the same method on AGX Orin, I encountered failure.

FDT /boot/dtb/kernel_tegra234-p3737-0000+p3701-0000-nv.dtb
OVERLAYS /boot/tegra234-p3737-camera-mycamera-overlay.dtbo

There are no hints now that would allow me to debug further. Is there any way to carry out troubleshooting of the problem?

@JerryChang

3

hello xumm_td,

just double check your steps To Create and Apply a DTB Overlay File.
since Orin NX/Nano series they’re using different device tree with AGX Orin.

4

Of course I know this.

To verify my idea, I made a small modification to the source code provided by the official tegra234-p3737-camera-e3333-overlay.dts and attempted to modify /boot/extlinux/extlinux.conf by adding the following two lines:

FDT /boot/dtb/kernel_tegra234-p3737-0000+p3701-0000-nv.dtb
OVERLAYS /boot/tegra234-p3737-camera-e3333-overlay.dtbo

Specifically, my modification is as follows:
Changed

sysfs-device-tree = "/sys/firmware/devicetree/base/bus@0/i2c@3180000/tca9548@77/i2c@0/ov5693_a@36";

to

sysfs-device-tree = "/sys/firmware/devicetree/base/bus@0/i2c@3180000/tca9548@77/i2c@0/ov5693_aaa@36";

If the OVERLAYS mechanism is effective, I should see changes in the sysfs. However, there are no changes at all.

Therefore, I am seeking your help. How can I confirm that the OVERLAYS mechanism is effective on AGX Orin@JP6.0? Are there any better debugging methods or tools available?

5

hello xumm_td,

did you confirm you’re choosing correct boot options for loading those FDT/OVERLAYS entries?
you may also sharing your extlinux.conf for reference.

anyways,
we could confirm it’s worked normally on AGX Orin since we’ve using Jetson-IO to toggle CSI connector as following.
for instance,

LABEL JetsonIO
        MENU LABEL Custom Header Config: <CSI Jetson Camera Dual-IMX274>
        ...
        FDT /boot/dtb/kernel_tegra234-p3737-0000+p3701-0005-nv.dtb
        OVERLAYS /boot/tegra234-p3737-camera-dual-imx274-overlay.dtbo
6

extlinux.zip (748 Bytes)

Please check attachment.

7

@JerryChang

I did not use any of my own code but attempted to enable the e3333 camera using the jetson-io mechanism. The /boot/extlinux/extlinux.conf file is as follows:

$ cat /boot/extlinux/extlinux.conf
TIMEOUT 30
DEFAULT JetsonIO

MENU TITLE L4T boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      INITRD /boot/initrd
      APPEND ${cbootargs} root=PARTUUID=261d21c9-15e9-4998-8423-5fdb14dc5ea3 rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 nospectre_bhb video=efifb:off console=tty0 nv-auto-config 

LABEL JetsonIO
        MENU LABEL Custom Header Config: <CSI Jetson Camera E3333 module>
        LINUX /boot/Image
        FDT /boot/dtb/kernel_tegra234-p3737-0000+p3701-0000-nv.dtb
        INITRD /boot/initrd
        APPEND ${cbootargs} root=PARTUUID=261d21c9-15e9-4998-8423-5fdb14dc5ea3 rw rootwait rootfstype=ext4 mminit_loglevel=4 console=ttyTCU0,115200 console=ttyAMA0,115200 firmware_class.path=/etc/firmware fbcon=map:0 net.ifnames=0 nospectre_bhb video=efifb:off console=tty0 nv-auto-config
        OVERLAYS /boot/tegra234-p3737-camera-e3333-overlay.dtbo

According to the tegra234-p3737-camera-e3333-overlay.dts source code, a series of configurations related to ov5693 are enabled. However, this is not the case in reality.

$ cat /sys/firmware/devicetree/base/bus@0/i2c@3180000/tca9548@77/i2c@0/ov5693_a@36/status 
disabled

I connected to the debug serial port of the AGX Orin and saw the following information, which lacks the messages indicating loading the dtb and dtbo from the rootfs.

L4TLauncher: Attempting Direct Boot
L4T boot options
0: primary kernel
1: Custom Header Config: <CSI Jetson Camera E3333 module>
Press 0-1 to boot selection within 3.0 seconds.
Press any other key to boot default (Option: 1)
EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from configuration table
EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path
EFI stub: Exiting boot services...

In this case, how do I confirm that OVERLAYS setting is in effect?

I am at my wit’s end. Please help me, thank you!

8

hello xumm_td,

do you have e3333 camera module mounted for testing?
re-cap from [Release Notes (r36.3)].

This line causes the following tasks to completed:
● If a specific camera board is found when the kernel boots, the override data is
applied to that camera board’s tree nodes.
● The tree nodes are made available for the system to use.

12

hello xumm_td,

according to UEFI code snippet as following.

STATIC
EFI_STATUS
ProcessOverlayDeviceTree (...)
..

  TargetName = fdt_getprop (FdtOverlay, 0, "overlay-name", &TargetLen);
  if ((TargetName != NULL) && (TargetLen != 0)) {
    DEBUG ((DEBUG_ERROR, "Processing \"%a\" DTB overlay\n", TargetName));
  }

you may enable debug flags for checking all dtbo files loaded by UEFI.
please see-also Home · NVIDIA/edk2-nvidia Wiki · GitHub to rebuilt UEFI.

14

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