diff --git a/APMrover2/APMrover2.cpp b/APMrover2/APMrover2.cpp
index 6d40bb01bf..c0cc3068cb 100644
--- a/APMrover2/APMrover2.cpp
+++ b/APMrover2/APMrover2.cpp
@@ -417,6 +417,9 @@ void Rover::update_current_mode(void)
         set_reverse(false);
         if (rtl_complete || verify_RTL()) {
             // we have reached destination so stop where we are
+            if (channel_throttle->servo_out != g.throttle_min.get()) {
+                gcs_send_mission_item_reached_message(0);
+            }
             channel_throttle->servo_out = g.throttle_min.get();
             channel_steer->servo_out = 0;
             lateral_acceleration = 0;
diff --git a/libraries/AP_Arming/AP_Arming.cpp b/libraries/AP_Arming/AP_Arming.cpp
index 700be7c3f4..73b0e58c55 100644
--- a/libraries/AP_Arming/AP_Arming.cpp
+++ b/libraries/AP_Arming/AP_Arming.cpp
@@ -326,7 +326,9 @@ bool AP_Arming::gps_checks(bool report)
                                                  "PreArm: GPS %d has not been fully configured",
                                                   first_unconfigured);
             }
+#if CONFIG_HAL_BOARD != HAL_BOARD_SITL
             return false;
+#endif
         }
     }
     return true;
diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_LightWareSerial.cpp b/libraries/AP_RangeFinder/AP_RangeFinder_LightWareSerial.cpp
index bac5c389f9..7f52a04eaf 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_LightWareSerial.cpp
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_LightWareSerial.cpp
@@ -75,7 +75,7 @@ bool AP_RangeFinder_LightWareSerial::get_reading(uint16_t &reading_cm)
     }
 
     // we need to write a byte to prompt another reading
-    uart->write('\n');
+    uart->write('d');
 
     if (count == 0) {
         return false;
diff --git a/mk/px4_targets.mk b/mk/px4_targets.mk
index 6e59e16718..649c2edca5 100644
--- a/mk/px4_targets.mk
+++ b/mk/px4_targets.mk
@@ -83,10 +83,8 @@ module_mk:
 
 px4-v1: $(BUILDROOT)/make.flags CHECK_MODULES $(MAVLINK_HEADERS) $(PX4_ROOT)/Archives/px4fmu-v1.export $(SKETCHCPP) module_mk px4-io-v1
 	$(RULEHDR)
-	$(v) rm -f $(PX4_ROOT)/makefiles/$(PX4_V1_CONFIG_FILE)
 	$(v) cp $(PX4_V1_CONFIG_FILE) $(PX4_ROOT)/makefiles/nuttx/
 	$(v) $(PX4_MAKE) px4fmu-v1_APM
-	$(v) /bin/rm -f $(SKETCH)-v1.px4
 	$(v) arm-none-eabi-size $(PX4_ROOT)/Build/px4fmu-v1_APM.build/firmware.elf
 	$(v) cp $(PX4_ROOT)/Images/px4fmu-v1_APM.px4 $(SKETCH)-v1.px4
 	$(v) $(SKETCHBOOK)/Tools/scripts/add_git_hashes.py $(HASHADDER_FLAGS) "$(SKETCH)-v1.px4" "$(SKETCH)-v1.px4"
@@ -94,10 +92,8 @@ px4-v1: $(BUILDROOT)/make.flags CHECK_MODULES $(MAVLINK_HEADERS) $(PX4_ROOT)/Arc
 
 px4-v2: $(BUILDROOT)/make.flags CHECK_MODULES $(MAVLINK_HEADERS) $(PX4_ROOT)/Archives/px4fmu-v2.export $(SKETCHCPP) module_mk px4-io-v2
 	$(RULEHDR)
-	$(v) rm -f $(PX4_ROOT)/makefiles/$(PX4_V2_CONFIG_FILE)
 	$(v) cp $(PX4_V2_CONFIG_FILE) $(PX4_ROOT)/makefiles/nuttx/
 	$(PX4_MAKE) px4fmu-v2_APM
-	$(v) /bin/rm -f $(SKETCH)-v2.px4
 	$(v) arm-none-eabi-size $(PX4_ROOT)/Build/px4fmu-v2_APM.build/firmware.elf
 	$(v) cp $(PX4_ROOT)/Images/px4fmu-v2_APM.px4 $(SKETCH)-v2.px4
 	$(v) $(SKETCHBOOK)/Tools/scripts/add_git_hashes.py $(HASHADDER_FLAGS) "$(SKETCH)-v2.px4" "$(SKETCH)-v2.px4"
@@ -105,10 +101,8 @@ px4-v2: $(BUILDROOT)/make.flags CHECK_MODULES $(MAVLINK_HEADERS) $(PX4_ROOT)/Arc
 
 px4-v4: $(BUILDROOT)/make.flags CHECK_MODULES $(MAVLINK_HEADERS) $(PX4_ROOT)/Archives/px4fmu-v4.export $(SKETCHCPP) module_mk
 	$(RULEHDR)
-	$(v) rm -f $(PX4_ROOT)/makefiles/$(PX4_V4_CONFIG_FILE)
 	$(v) cp $(PX4_V4_CONFIG_FILE) $(PX4_ROOT)/makefiles/nuttx/
 	$(PX4_MAKE) px4fmu-v4_APM
-	$(v) /bin/rm -f $(SKETCH)-v4.px4
 	$(v) arm-none-eabi-size $(PX4_ROOT)/Build/px4fmu-v4_APM.build/firmware.elf
 	$(v) cp $(PX4_ROOT)/Images/px4fmu-v4_APM.px4 $(SKETCH)-v4.px4
 	$(v) cp $(SKETCHBOOK)/mk/PX4/bootloader/px4fmuv4_bl.bin $(MK_DIR)/PX4/ROMFS/bootloader/fmu_bl.bin
@@ -150,29 +144,22 @@ px4-archives-clean:
 
 px4-io-v1: $(PX4_ROOT)/Archives/px4io-v1.export
 	$(v)+ $(MAKE) -C $(PX4_ROOT) -f $(PX4_ROOT)/Makefile.make px4io-v1_default
-	$(v) /bin/rm -f px4io-v1.bin
 	$(v) cp $(PX4_ROOT)/Images/px4io-v1_default.bin px4io-v1.bin
 	$(v) cp $(PX4_ROOT)/Build/px4io-v1_default.build/firmware.elf px4io-v1.elf
 	$(v) mkdir -p $(MK_DIR)/PX4/ROMFS/px4io/
-	$(v) rm -f $(MK_DIR)/PX4/ROMFS/px4io/px4io.bin
 	$(v) cp px4io-v1.bin $(MK_DIR)/PX4/ROMFS/px4io/px4io.bin
 	$(v) mkdir -p $(MK_DIR)/PX4/ROMFS/bootloader/
-	$(v) rm -f $(MK_DIR)/PX4/ROMFS/bootloader/fmu_bl.bin
 	$(v) cp $(SKETCHBOOK)/mk/PX4/bootloader/px4fmu_bl.bin $(MK_DIR)/PX4/ROMFS/bootloader/fmu_bl.bin
 	$(v) echo "PX4IOv1 Firmware is in px4io-v1.bin"
 
 
 px4-io-v2: $(PX4_ROOT)/Archives/px4io-v2.export
 	$(v)+ $(MAKE) -C $(PX4_ROOT) -f $(PX4_ROOT)/Makefile.make px4io-v2_default
-	$(v) /bin/rm -f px4io-v2.bin
-	$(v) cp $(PX4_ROOT)/Build/px4io-v2_default.build/firmware.bin px4io-v2.bin
 	$(v) cp $(PX4_ROOT)/Images/px4io-v2_default.bin px4io-v2.bin
 	$(v) cp $(PX4_ROOT)/Build/px4io-v2_default.build/firmware.elf px4io-v2.elf
 	$(v) mkdir -p $(MK_DIR)/PX4/ROMFS/px4io/
-	$(v) rm -f $(MK_DIR)/PX4/ROMFS/px4io/px4io.bin
 	$(v) cp px4io-v2.bin $(MK_DIR)/PX4/ROMFS/px4io/px4io.bin
 	$(v) mkdir -p $(MK_DIR)/PX4/ROMFS/bootloader/
-	$(v) rm -f $(MK_DIR)/PX4/ROMFS/bootloader/fmu_bl.bin
 	$(v) cp $(SKETCHBOOK)/mk/PX4/bootloader/px4fmuv2_bl.bin $(MK_DIR)/PX4/ROMFS/bootloader/fmu_bl.bin
 	$(v) echo "PX4IOv2 Firmware is in px4io-v2.bin"