I'm new to nRF52833 and when I am working with my DK of DFU modules, I'm getting really confused with option NRF_DFU_REQUIRE_SIGNED_APP_UPDATE and NRF_BL_APP_SIGNATURE_CHECK_REQUIRED. What exactly is the difference between these two?
I read nrf_dfu_validation.c and found NRF_DFU_REQUIRE_SIGNED_APP_UPDATE determined whether signature is required. So is the option responsible for secure firmware update? Then how about NRF_BL_APP_SIGNATURE_CHECK_REQUIRED? Dose it have something to do with DFU(Literally I think so)? How and When?