Custom Kernel Build

Hi, We are trying to build the custom kernel and we have followed the procedure given by NVIDIA.
1.We have downloaded public resources , ran all the commands and output files are generated.
2.We have downloaded the Tegra186_Linux_R32.4.4_aarch64 package and replaced the img and dtsi files with new generated files.
3.Sample root files are copied into rootfs folder of Tegra186_Linux_R32.4.4_aarch64.
3.We ran the flash.sh command and during system img built, it is throwing an error of extlinux.conf not found.

Can any one check and let us know what to do further.

Issue solved, after executing applybinaries. she command.

Thank you