@veye_xumm Yes, I made sure to use the signed version and used the file you mentioned. I made sure that the signed DTB file tegra194-p3668-all-p3509-0000.dtb was in the /boot directory.

Also I edited the extlinux.conf file and the FDT line to the end, so it looks like this:

TIMEOUT 30
DEFAULT primary

MENU TITLE L4T boot options

LABEL primary
MENU LABEL primary kernel
LINUX /boot/arducam/Image
INITRD /boot/initrd
APPEND ${cbootargs} quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyTCU0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0
FDT /boot/tegra194-p3668-all-p3509-0000.dtb

I did a reboot but it didn't work. I ran the command "ls /sys/bus/i2c/drivers/" but there was no imx307 directory present. Also I ran the command "ls /proc/device-tree/cam_i2cmux/i2c@*" but the camera model was not listed.

Please let me know. Thanks!

@techies P.S. The text editor reformatted the extlinux.conf but the formatting on the Xavier NX is correct.

LABEL primary
MENU LABEL primary kernel
LINUX /boot/arducam/Image
FDT /boot/tegra194-p3668-all-p3509-0000.dtb
INITRD /boot/initrd
APPEND ${cbootargs} quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyTCU0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0

I followed the instructions found in http://wiki.veye.cc/index.php/VEYE_CS_Camera_for_Jetson_TX2

My environment:
cat /etc/nv_tegra_release

R32 (release), REVISION: 6.1, GCID: 27863751, BOARD: t186ref, EABI: aarch64, DATE: Mon Jul 26 19:36:31 UTC 2021

1. There seems to be a typo in the Image copy: it says,
   sudo cp <path to your Image dir>/Image /boot/Image -f
   sudo cp <path to your Image dir>/Image.sig /boot/Image -f

I believe it should be:
sudo cp <path to your Image dir>/Image /boot/Image -f
sudo cp <path to your Image dir>/Image.sig /boot/Image.sig -f

In other words, the SIG file should be copied to the SIG file in /boot

2. So I copied the correct Image and Image.sig files from Git to /boot, then I updated the extlinux.conf file:
   LABEL primary
   MENU LABEL primary kernel
   LINUX /boot/arducam/Image
   FDT /boot/tegra194-p3668-all-p3509-0000.dtb
   INITRD /boot/initrd
   APPEND ${cbootargs} quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyTCU0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0

I didn't work! After reboot, ls /sys/bus/i2c/drivers/ does not show the new driver and ls /proc/device-tree/cam_i2cmux/i2c@* does not show the camera model.

Please let me know what is the solution!