Is It correct that secureboot_R32.3.1_aarch64.tbz2 is a latest thing?
Applies to: Jetson Xavier NX and Jetson AGX Xavier series only
You can flash with initrd (initial RAM disk) to both internal media and external media connected to a Jetson device. This procedure uses initrd and USB device mode. It requires that the Secureboot package be installed; see Installing the Secureboot Package in the topic Secureboot.
Tools and instructions for flashing with initrd may be found in the directory /Linux_for_Tegra/tools/kernel_flash/. For more detailed information, see README_initrd_flash.txt in the same directory.
To flash jetson xavier nx with initrd, it require installing secure boot package.