What dtb file TX2 boot from?

Hi,everybody,

Before in TX1,the dtb file used indicate in /boot/extlinux/extlinux.conf

FDT /boot/tegra210-jetson-tx1-p2597-2180-a01-devkit.dtb

But now in TX2,there no code to indicate what dtb file TX2 boot from.

TIMEOUT 30
DEFAULT primary

MENU TITLE p2771-0000 eMMC boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      APPEND fbcon=map:0 net.ifnames=0 console=tty0 OS=l4t console=ttyS0,115200n8 memtype=0 video=tegrafb no_console_suspend=1 earlycon=uart8250,mmio32,0x03100000 gpt tegraid=18.1.2.0.0 tegra_keep_boot_clocks maxcpus=6 android.kerneltype=normal androidboot.serialno=0335115020673 vpr_resize root=/dev/mmcblk0p1 rw rootwait

And I found although I delete all dtb files,TX2 can boot normally.Why?

Hi CalmCar, please see this wiki page: http://elinux.org/Jetson/TX2_DTB

On TX2, you can add the FDT line back into extlinux.conf to manually specify the DTB.

Hi,dusty_nv

The second question:Why I delete all dtb file,TX2 can startup also?

Thanks

By default the boot doesn’t utilize the fdt method. Unless it is explicitly stated in the extlinux.conf it uses dts path [cospan’s post ]
However, if you like you could add the line pointing to dtb file to boot from.

Reference http://elinux.org/Jetson/TX2_DTB
https://devtalk.nvidia.com/default/topic/1001443/jetson-tx2/extlinux-conf-fdt-no-longer-used-for-dtb-file-specification-/post/5116102/#5116102

The boot loader itself sets up a device tree. The dtb file…if used…will override the U-Boot version. The version used by flash.sh is in a conf file, e.g., “jetson-tx2.conf” is a symbolic link to “p2771-0000-devkit-24x7.conf”, and this sets up with “tegra186-a02-bpmp-quill-p3310-1000-a00-00-te770d-ucm2.dtb”.