commander: enable arming on boot

src/modules/commander/Commander.cpp

@@ -1870,6 +1870,7 @@ void Commander::run()
 #endif // BOARD_HAS_POWER_CONTROL
 
 	_boot_timestamp = hrt_absolute_time();
+	_arm_on_boot_requested = _param_com_arm_on_boot.get();
 
 	arm_auth_init(&_mavlink_log_pub, &_vehicle_status.system_id);
 
@@ -1949,6 +1950,20 @@ void Commander::run()
 
 			perf_end(_preflight_check_perf);
 			checkAndInformReadyForTakeoff();
+
+			// Arm automatically on boot once preflight checks pass
+			// _arm_on_boot_done prevents re-arming after disarming
+			const bool should_arm_on_boot = _arm_on_boot_requested
+							&& !_arm_on_boot_done
+							&& !isArmed()
+							&& hrt_elapsed_time(&_boot_timestamp) > 5_s
+							&& pre_flight_checks_pass;
+
+			if (should_arm_on_boot) {
+				if (arm(arm_disarm_reason_t::mission_start, false) != TRANSITION_DENIED) {
+					_arm_on_boot_done = true;
+				}
+			}
 		}
 
 		// handle commands last, as the system needs to be updated to handle them