A request to enter the loader or replace the bootloader

InformationStart-up and what the board reports

What ArduPilot says:

Entering DFU mode
Refusing DFU for secure firmware
Magic not set
Bootloader not signed

These answer commands that touch how firmware gets onto the board. “Entering DFU mode”: the board restarts into the processor's own USB loader (DFU), the way a board is flashed for the first time; it vanishes from the ground station until it is power-cycled. “Refusing DFU for secure firmware” and “Bootloader not signed”: this firmware uses signed secure boot and will not take a step that goes round the signature. “Magic not set”: a command to rewrite the bootloader came without its confirmation number, and nothing was done.

Where to do it:Setup & Tuning Guide

The code that sends it

Entering DFU mode

libraries/GCS_MAVLink/GCS_Common.cpp GCS_MAVLINK::handle_preflight_reboot() · Open in ArduPilot Copter-4.7.1

Refusing DFU for secure firmware

libraries/GCS_MAVLink/GCS_Common.cpp GCS_MAVLINK::handle_preflight_reboot() · Open in ArduPilot Copter-4.7.1

Magic not set

libraries/GCS_MAVLink/GCS_Common.cpp GCS_MAVLINK::handle_command_flash_bootloader() · Open in ArduPilot Copter-4.7.1

Bootloader not signed

libraries/GCS_MAVLink/GCS_Common.cpp GCS_MAVLINK::handle_command_flash_bootloader() · Open in ArduPilot Copter-4.7.1