Flash Specific Device Tree

[marc.armstrong]

I’m working with the Jetson Xavier NX dev (I think, as it has 16gb local memory) and there are two available device trees to flash,

tegra194-p3668-0001-p3509-0000.dtb and tegra194-p3668-0000-p3509-0000.dtb.

I believe, both are very similar and I think the p3668-0001 device tree is the correct one, however I would liked to know how to flash the p3668-0000 tree, to keep the hardware team happy when diagnosing hardware issues.

To update the device tree, I use the command

sudo ./flash.sh -r -k kernel-dtb jetson-xavier-nx-devkit-emmc mmcblk0p1

This doesn’t allow me to specify the device tree though.

I can specify the device tree when flashing the kernel image.

sudo ./flash.sh -r -d kernel/dtb/tegra194-p3668-0001-p3509-0000.dtb -K kernel/Image jetson-xavier-nx-devkit-emmc mmcblk0p1

Can I do something similar when updating only the device tree?

Thanks.

[jchaves]

Hi,

I believe you should be able to update only a specific device tree by reducing your own command:

sudo ./flash.sh -r -d kernel/dtb/tegra194-p3668-0001-p3509-0000.dtb jetson-xavier-nx-devkit-emmc mmcblk0p1

Anyways another trick that I consider faster is to update only the device tree by modifying the /boot/extlinux/extlinux.conf file to something like:

TIMEOUT 30
DEFAULT primary

MENU TITLE L4T boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      INITRD /boot/initrd
      FDT /boot/dtb/tegra194-p3668-0001-p3509-0000.dtb
      APPEND ${cbootargs} quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 isolcpus=1-2

The new line that you should need is the FDT one. That way you should only need to copy (through scp or USB flash drive) the dtb file to the specified file path.

Jafet Chaves,
Embedded SW Engineer at RidgeRun
Contact us: support@ridgerun.com
Developers wiki: https://developer.ridgerun.com/
Website: www.ridgerun.com