Arm prevention if Rescue is activated

src/main/fc/core.c

@@ -282,6 +282,11 @@ void updateArmingStatus(void)
             } else {
                 setArmingDisabled(ARMING_DISABLED_GPS);
             }
+            if (IS_RC_MODE_ACTIVE(BOXGPSRESCUE)) {
+                setArmingDisabled(ARMING_DISABLED_RESC);
+            } else {
+                unsetArmingDisabled(ARMING_DISABLED_RESC);
+            }
         }
 #endif
 
@@ -828,7 +833,7 @@ bool processRx(timeUs_t currentTimeUs)
     }
 
 #ifdef USE_GPS_RESCUE
-    if (IS_RC_MODE_ACTIVE(BOXGPSRESCUE) || (failsafeIsActive() && failsafeConfig()->failsafe_procedure == FAILSAFE_PROCEDURE_GPS_RESCUE)) {
+    if (ARMING_FLAG(ARMED) && (IS_RC_MODE_ACTIVE(BOXGPSRESCUE) || (failsafeIsActive() && failsafeConfig()->failsafe_procedure == FAILSAFE_PROCEDURE_GPS_RESCUE))) {
         if (!FLIGHT_MODE(GPS_RESCUE_MODE)) {
             ENABLE_FLIGHT_MODE(GPS_RESCUE_MODE);
         }

src/main/fc/runtime_config.c

@@ -53,7 +53,8 @@ const char *armingDisableFlagNames[]= {
     "MSP",
     "PARALYZE",
     "GPS",
-    "ARMSWITCH"
+    "RESCUE SW",
+    "ARMSWITCH",
 };
 
 static armingDisableFlags_e armingDisableFlags = 0;

src/main/fc/runtime_config.h

@@ -57,10 +57,11 @@ typedef enum {
     ARMING_DISABLED_MSP             = (1 << 16),
     ARMING_DISABLED_PARALYZE        = (1 << 17),
     ARMING_DISABLED_GPS             = (1 << 18),
-    ARMING_DISABLED_ARM_SWITCH      = (1 << 19), // Needs to be the last element, since it's always activated if one of the others is active when arming
+    ARMING_DISABLED_RESC            = (1 << 19),
+    ARMING_DISABLED_ARM_SWITCH      = (1 << 20), // Needs to be the last element, since it's always activated if one of the others is active when arming
 } armingDisableFlags_e;
 
-#define ARMING_DISABLE_FLAGS_COUNT 20
+#define ARMING_DISABLE_FLAGS_COUNT 21
 
 extern const char *armingDisableFlagNames[ARMING_DISABLE_FLAGS_COUNT];
 

src/main/flight/gps_rescue.c

@@ -427,17 +427,17 @@ void updateGPSRescueState(void)
             hoverThrottle = gpsRescueConfig()->throttleHover;
         }
 
-        // Minimum distance detection.  Disarm regardless of sanity check configuration.  Rescue too close is never a good idea.
+        // Minimum distance detection.
         if (rescueState.sensor.distanceToHomeM < gpsRescueConfig()->minRescueDth) {
-            // Never allow rescue mode to engage as a failsafe when too close or when disarmed.
-            if (rescueState.isFailsafe || !ARMING_FLAG(ARMED)) {
-                rescueState.failure = RESCUE_TOO_CLOSE;
+            rescueState.failure = RESCUE_TOO_CLOSE;
+            
+            // Never allow rescue mode to engage as a failsafe when too close.
+            if (rescueState.isFailsafe) {
                 setArmingDisabled(ARMING_DISABLED_ARM_SWITCH);
                 disarm();
-            } else {
-                // Leave it up to the sanity check setting
-                rescueState.failure = RESCUE_TOO_CLOSE;
             }
+            
+            // When not in failsafe mode: leave it up to the sanity check setting.
         }
 
         rescueState.phase = RESCUE_ATTAIN_ALT;

src/test/Makefile

@@ -39,6 +39,9 @@ arming_prevention_unittest_SRC := \
 		$(USER_DIR)/fc/runtime_config.c \
 		$(USER_DIR)/common/bitarray.c
 
+arming_prevention_unittest_DEFINES := \
+            USE_GPS_RESCUE=
+
 atomic_unittest_SRC := \
 		$(USER_DIR)/build/atomic.c \
 		$(TEST_DIR)/atomic_unittest_c.c

src/test/unit/arming_prevention_unittest.cc

@@ -43,6 +43,7 @@ extern "C" {
     #include "sensors/acceleration.h"
     #include "sensors/gyro.h"
     #include "telemetry/telemetry.h"
+    #include "flight/gps_rescue.h"
 
     PG_REGISTER(accelerometerConfig_t, accelerometerConfig, PG_ACCELEROMETER_CONFIG, 0);
     PG_REGISTER(blackboxConfig_t, blackboxConfig, PG_BLACKBOX_CONFIG, 0);
@@ -54,6 +55,7 @@ extern "C" {
     PG_REGISTER(systemConfig_t, systemConfig, PG_SYSTEM_CONFIG, 0);
     PG_REGISTER(telemetryConfig_t, telemetryConfig, PG_TELEMETRY_CONFIG, 0);
     PG_REGISTER(failsafeConfig_t, failsafeConfig, PG_FAILSAFE_CONFIG, 0);
+    PG_REGISTER(gpsRescueConfig_t, gpsRescueConfig, PG_GPS_RESCUE, 0);
 
     float rcCommand[4];
     int16_t rcData[MAX_SUPPORTED_RC_CHANNEL_COUNT];
@@ -612,6 +614,118 @@ TEST(ArmingPreventionTest, WhenUsingSwitched3DModeThenNormalThrottleArmingCondit
     EXPECT_EQ(0, getArmingDisableFlags());
 }
 
+TEST(ArmingPreventionTest, Rescue)
+{
+    // given
+    simulationFeatureFlags = 0;
+    simulationTime = 0;
+    gyroCalibDone = true;
+
+    // and
+    modeActivationConditionsMutable(0)->auxChannelIndex = 0;
+    modeActivationConditionsMutable(0)->modeId = BOXARM;
+    modeActivationConditionsMutable(0)->range.startStep = CHANNEL_VALUE_TO_STEP(1750);
+    modeActivationConditionsMutable(0)->range.endStep = CHANNEL_VALUE_TO_STEP(CHANNEL_RANGE_MAX);
+    modeActivationConditionsMutable(1)->auxChannelIndex = 1;
+    modeActivationConditionsMutable(1)->modeId = BOXGPSRESCUE;
+    modeActivationConditionsMutable(1)->range.startStep = CHANNEL_VALUE_TO_STEP(1750);
+    modeActivationConditionsMutable(1)->range.endStep = CHANNEL_VALUE_TO_STEP(CHANNEL_RANGE_MAX);
+    useRcControlsConfig(NULL);
+
+    // and
+    rxConfigMutable()->mincheck = 1050;
+
+    // given
+    rcData[THROTTLE] = 1000;
+    rcData[AUX1] = 1000;
+    rcData[AUX2] = 1800; // Start out with rescue enabled
+    ENABLE_STATE(SMALL_ANGLE);
+
+    // when
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_FALSE(ARMING_FLAG(ARMED));
+    EXPECT_TRUE(isArmingDisabled());
+    EXPECT_EQ(ARMING_DISABLED_RESC, getArmingDisableFlags());
+    EXPECT_TRUE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+
+    // given
+    // arm
+    rcData[AUX1] = 1800;
+
+    // when
+    tryArm();
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_FALSE(ARMING_FLAG(ARMED));
+    EXPECT_TRUE(isArmingDisabled());
+    EXPECT_EQ(ARMING_DISABLED_ARM_SWITCH|ARMING_DISABLED_RESC, getArmingDisableFlags());
+    EXPECT_TRUE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+
+    // given
+    // disarm
+    rcData[AUX1] = 1000;
+
+    // when
+    disarm();
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_FALSE(ARMING_FLAG(ARMED));
+    EXPECT_TRUE(isArmingDisabled());
+    EXPECT_EQ(ARMING_DISABLED_RESC, getArmingDisableFlags());
+    EXPECT_TRUE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+
+    // given
+    // disable Rescue
+    rcData[AUX2] = 1000;
+
+    // when
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_FALSE(ARMING_FLAG(ARMED));
+    EXPECT_FALSE(isArmingDisabled());
+    EXPECT_EQ(0, getArmingDisableFlags());
+    EXPECT_FALSE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+
+    // given
+    // arm
+    rcData[AUX1] = 1800;
+
+    // when
+    tryArm();
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_TRUE(ARMING_FLAG(ARMED));
+    EXPECT_FALSE(isArmingDisabled());
+    EXPECT_EQ(0, getArmingDisableFlags());
+    EXPECT_FALSE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+
+    // given
+    // disarm
+    rcData[AUX1] = 1000;
+
+    // when
+    disarm();
+    updateActivatedModes();
+    updateArmingStatus();
+
+    // expect
+    EXPECT_FALSE(ARMING_FLAG(ARMED));
+    EXPECT_FALSE(isArmingDisabled());
+    EXPECT_EQ(0, getArmingDisableFlags());
+    EXPECT_FALSE(IS_RC_MODE_ACTIVE(BOXGPSRESCUE));
+}
+
 TEST(ArmingPreventionTest, ParalyzeOnAtBoot)
 {
     // given