nrfutil pkg generate --application ble_app_blinky_pca10040e_s112.hex --application-version-string "1.1.0" --hw-version 52 --sd-req 0x0103 --key-file private.pem secure_dfu_test_images/app_dfu_pkg.zip
nrfutil pkg display secure_dfu_test_images/app_dfu_pkg.zip 
pause