*** Booting Zephyr OS build v2.3.0-rc1-ncs1  ***
[00:00:00.003,143] <inf> mcuboot: Starting bootloader
[00:00:00.009,460] <inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
[00:00:00.019,714] <inf> mcuboot: Boot source: none
[00:00:00.025,238] <wrn> mcuboot: Failed reading image headers; Image=0
[00:00:00.032,775] <err> mcuboot: Unable to find bootable image