diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8ea64e142..96bc56e3e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -31,6 +31,7 @@ build_template_app:
     SDK_PATH: "$CI_PROJECT_DIR"
     IDF_PATH: "$CI_PROJECT_DIR"
     GIT_STRATEGY: clone
+    BATCH_BUILD: "1"
 
   script:
     - git clone https://github.com/espressif/esp-idf-template.git
@@ -39,13 +40,11 @@ build_template_app:
     # using on esp-idf. If it doesn't exist then just stick to the default
     # branch
     - git checkout ${CI_BUILD_REF_NAME} || echo "Using esp-idf-template default branch..."
-    - make defconfig
     # Test debug build (default)
     - make all V=1
     # Now test release build
     - make clean
     - sed -i.bak -e's/CONFIG_OPTIMIZATION_LEVEL_DEBUG\=y/CONFIG_OPTIMIZATION_LEVEL_RELEASE=y/' sdkconfig
-    - make defconfig
     - make all V=1
     # Check if there are any stray printf/ets_printf references in WiFi libs
     - cd ../components/esp32/lib
@@ -63,6 +62,8 @@ build_template_app:
     SDK_PATH: "$CI_PROJECT_DIR"
     IDF_PATH: "$CI_PROJECT_DIR"
     GIT_STRATEGY: clone
+    BATCH_BUILD: "1"
+
 
 build_ssc:
   <<: *build_template
@@ -103,7 +104,6 @@ build_esp_idf_tests:
   script:
     - cd tools/unit-test-app
     - git checkout ${CI_BUILD_REF_NAME} || echo "Using default branch..."
-    - make defconfig
     - make TESTS_ALL=1
     - python UnitTestParser.py
 
diff --git a/components/bootloader/src/main/Makefile.projbuild b/components/bootloader/src/main/Makefile.projbuild
new file mode 100644
index 000000000..c368c6841
--- /dev/null
+++ b/components/bootloader/src/main/Makefile.projbuild
@@ -0,0 +1,4 @@
+# Submodules normally added in component.mk, but fully qualified
+# paths can be added at this level (we need binary librtc to be
+# available to link bootloader).
+COMPONENT_SUBMODULES += $(IDF_PATH)/components/esp32/lib
diff --git a/components/bootloader/src/main/component.mk b/components/bootloader/src/main/component.mk
index 2069665d1..12fdf8efa 100644
--- a/components/bootloader/src/main/component.mk
+++ b/components/bootloader/src/main/component.mk
@@ -14,10 +14,10 @@ COMPONENT_ADD_LDFLAGS := -L $(COMPONENT_PATH) -lmain $(addprefix -T ,$(LINKER_SC
 
 COMPONENT_ADD_LINKER_DEPS := $(LINKER_SCRIPTS)
 
-ifdef IS_BOOTLOADER_BUILD
 # following lines are a workaround to link librtc into the
 # bootloader, until clock setting code is in a source-based esp-idf
 # component. See also rtc_printf() in bootloader_start.c
+#
+# See also matching COMPONENT_SUBMODULES line in Makefile.projbuild
 COMPONENT_ADD_LDFLAGS += -L $(IDF_PATH)/components/esp32/lib/ -lrtc_clk -lrtc
 COMPONENT_EXTRA_INCLUDES += $(IDF_PATH)/components/esp32/
-endif
diff --git a/components/bootloader_support/src/bootloader_random.c b/components/bootloader_support/src/bootloader_random.c
index b58ebe941..5a00d0cf5 100644
--- a/components/bootloader_support/src/bootloader_random.c
+++ b/components/bootloader_support/src/bootloader_random.c
@@ -135,4 +135,8 @@ void bootloader_random_disable(void)
     /* Reset i2s peripheral */
     SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_I2S0_RST);
     CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_I2S0_RST);
+
+    /* Disable pull supply voltage to SAR ADC */
+    CLEAR_PERI_REG_MASK(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_ENT_RTC);
+    SET_PERI_REG_BITS(RTC_CNTL_TEST_MUX_REG, RTC_CNTL_DTEST_RTC, 0, RTC_CNTL_DTEST_RTC_S);
 }
diff --git a/components/bt/Kconfig b/components/bt/Kconfig
index d2227868c..63dce8d1f 100644
--- a/components/bt/Kconfig
+++ b/components/bt/Kconfig
@@ -17,6 +17,15 @@ config BLUEDROID_MEM_DEBUG
 	help
 		Bluedroid memory debug
 
+config BT_DRAM_RELEASE
+	bool "Release DRAM from Classic BT controller"
+    depends on BT_ENABLED
+	default n
+	help
+		This option should only be used when BLE only.
+		Open this option will release about 30K DRAM from Classic BT.
+		The released DRAM will be used as system heap memory.
+
 # Memory reserved at start of DRAM for Bluetooth stack
 config BT_RESERVE_DRAM
     hex
diff --git a/components/bt/bluedroid/api/include/esp_gap_ble_api.h b/components/bt/bluedroid/api/include/esp_gap_ble_api.h
index 64aff1fb1..8b5882d27 100644
--- a/components/bt/bluedroid/api/include/esp_gap_ble_api.h
+++ b/components/bt/bluedroid/api/include/esp_gap_ble_api.h
@@ -46,6 +46,8 @@ typedef enum {
     ESP_GAP_BLE_SCAN_RESULT_EVT,                            /*!< When one scan result ready, the event comes each time */
     ESP_GAP_BLE_ADV_DATA_RAW_SET_COMPLETE_EVT,              /*!< When raw advertising data set complete, the event comes */
     ESP_GAP_BLE_SCAN_RSP_DATA_RAW_SET_COMPLETE_EVT,         /*!< When raw advertising data set complete, the event comes */
+    ESP_GAP_BLE_ADV_START_COMPLETE_EVT,                     /*!< When start advertising complete, the event comes */
+    ESP_GAP_BLE_SCAN_START_COMPLETE_EVT,                    /*!< When start scan complete, the event comes */
 } esp_gap_ble_cb_event_t;
 
 /// Advertising data maximum length
@@ -284,6 +286,18 @@ typedef union {
     struct ble_scan_rsp_data_raw_cmpl_evt_param {
         esp_bt_status_t status;                     /*!< Indicate the set raw advertising data operation success status */
     } scan_rsp_data_raw_cmpl;                       /*!< Event parameter of ESP_GAP_BLE_SCAN_RSP_DATA_RAW_SET_COMPLETE_EVT */
+    /**
+     * @brief ESP_GAP_BLE_ADV_START_COMPLETE_EVT
+     */
+    struct ble_adv_start_cmpl_evt_param {
+        esp_bt_status_t status;                     /*!< Indicate advertising start operation success status */
+    } adv_start_cmpl;                               /*!< Event parameter of ESP_GAP_BLE_ADV_START_COMPLETE_EVT */
+    /**
+     * @brief ESP_GAP_BLE_SCAN_START_COMPLETE_EVT
+     */
+    struct ble_scan_start_cmpl_evt_param {
+        esp_bt_status_t status;                     /*!< Indicate scan start operation success status */
+    } scan_start_cmpl;                              /*!< Event parameter of ESP_GAP_BLE_SCAN_START_COMPLETE_EVT */
 } esp_ble_gap_cb_param_t;
 
 /**
diff --git a/components/bt/bluedroid/bta/dm/bta_dm_act.c b/components/bt/bluedroid/bta/dm/bta_dm_act.c
index 66eb55dac..8ebd3a8f3 100644
--- a/components/bt/bluedroid/bta/dm/bta_dm_act.c
+++ b/components/bt/bluedroid/bta/dm/bta_dm_act.c
@@ -4534,12 +4534,11 @@ void bta_dm_ble_observe (tBTA_DM_MSG *p_data)
         bta_dm_search_cb.p_scan_cback = p_data->ble_observe.p_cback;
         if ((status = BTM_BleObserve(TRUE, p_data->ble_observe.duration,
                                      bta_dm_observe_results_cb, bta_dm_observe_cmpl_cb)) != BTM_CMD_STARTED) {
-            tBTA_DM_SEARCH  data;
             APPL_TRACE_WARNING(" %s BTM_BleObserve  failed. status %d\n", __FUNCTION__, status);
-            data.inq_cmpl.num_resps = 0;
-            if (bta_dm_search_cb.p_scan_cback) {
-                bta_dm_search_cb.p_scan_cback(BTA_DM_INQ_CMPL_EVT, &data);
-            }
+        }
+        if (p_data->ble_observe.p_start_scan_cback) {
+            status = (status == BTM_CMD_STARTED ? BTA_SUCCESS : BTA_FAILURE);
+            p_data->ble_observe.p_start_scan_cback(status);
         }
     } else {
         bta_dm_search_cb.p_scan_cback = NULL;
@@ -4576,13 +4575,21 @@ void bta_dm_ble_set_adv_params (tBTA_DM_MSG *p_data)
 *******************************************************************************/
 void bta_dm_ble_set_adv_params_all  (tBTA_DM_MSG *p_data)
 {
-    BTM_BleSetAdvParamsStartAdv(p_data->ble_set_adv_params_all.adv_int_min,
+    tBTA_STATUS status = BTA_FAILURE;
+
+    if (BTM_BleSetAdvParamsStartAdv(p_data->ble_set_adv_params_all.adv_int_min,
                                 p_data->ble_set_adv_params_all.adv_int_max,
                                 p_data->ble_set_adv_params_all.adv_type,
                                 p_data->ble_set_adv_params_all.addr_type_own,
                                 p_data->ble_set_adv_params_all.p_dir_bda,
                                 p_data->ble_set_adv_params_all.channel_map,
-                                p_data->ble_set_adv_params_all.adv_filter_policy);
+                                p_data->ble_set_adv_params_all.adv_filter_policy) == BTM_SUCCESS) {
+        status = BTA_SUCCESS;
+    }
+
+    if (p_data->ble_set_adv_params_all.p_start_adv_cback) {
+        (*p_data->ble_set_adv_params_all.p_start_adv_cback)(status);
+    }
 }
 
 /*******************************************************************************
diff --git a/components/bt/bluedroid/bta/dm/bta_dm_api.c b/components/bt/bluedroid/bta/dm/bta_dm_api.c
index 132d2ea8f..413d6de55 100644
--- a/components/bt/bluedroid/bta/dm/bta_dm_api.c
+++ b/components/bt/bluedroid/bta/dm/bta_dm_api.c
@@ -1009,7 +1009,7 @@ void BTA_DmSetBleAdvParams (UINT16 adv_int_min, UINT16 adv_int_max,
 void BTA_DmSetBleAdvParamsAll (UINT16 adv_int_min, UINT16 adv_int_max,
                                UINT8 adv_type, tBLE_ADDR_TYPE addr_type_own,
                                tBTM_BLE_ADV_CHNL_MAP chnl_map, tBTM_BLE_AFP adv_fil_pol,
-                               tBLE_BD_ADDR *p_dir_bda)
+                               tBLE_BD_ADDR *p_dir_bda, tBTA_START_ADV_CMPL_CBACK p_start_adv_cb)
 {
 #if BLE_INCLUDED == TRUE
     tBTA_DM_API_BLE_ADV_PARAMS_ALL    *p_msg;
@@ -1029,6 +1029,7 @@ void BTA_DmSetBleAdvParamsAll (UINT16 adv_int_min, UINT16 adv_int_max,
         p_msg->addr_type_own    = addr_type_own;
         p_msg->channel_map      = chnl_map;
         p_msg->adv_filter_policy    = adv_fil_pol;
+        p_msg->p_start_adv_cback    = p_start_adv_cb;
         if (p_dir_bda != NULL) {
             p_msg->p_dir_bda = (tBLE_BD_ADDR *)(p_msg + 1);
             memcpy(p_msg->p_dir_bda, p_dir_bda, sizeof(tBLE_BD_ADDR));
@@ -2127,7 +2128,8 @@ void BTA_DmCloseACL(BD_ADDR bd_addr, BOOLEAN remove_dev, tBTA_TRANSPORT transpor
 **
 *******************************************************************************/
 extern void BTA_DmBleObserve(BOOLEAN start, UINT8 duration,
-                             tBTA_DM_SEARCH_CBACK *p_results_cb)
+                             tBTA_DM_SEARCH_CBACK *p_results_cb,
+                             tBTA_START_SCAN_CMPL_CBACK *p_start_scan_cb)
 {
     tBTA_DM_API_BLE_OBSERVE   *p_msg;
 
@@ -2140,6 +2142,7 @@ extern void BTA_DmBleObserve(BOOLEAN start, UINT8 duration,
         p_msg->start = start;
         p_msg->duration = duration;
         p_msg->p_cback = p_results_cb;
+        p_msg->p_start_scan_cback = p_start_scan_cb;
 
         bta_sys_sendmsg(p_msg);
     }
diff --git a/components/bt/bluedroid/bta/dm/bta_dm_int.h b/components/bt/bluedroid/bta/dm/bta_dm_int.h
index 7475ad254..9c5cbc4d8 100644
--- a/components/bt/bluedroid/bta/dm/bta_dm_int.h
+++ b/components/bt/bluedroid/bta/dm/bta_dm_int.h
@@ -471,7 +471,8 @@ typedef struct {
     BT_HDR                  hdr;
     BOOLEAN                 start;
     UINT16                  duration;
-    tBTA_DM_SEARCH_CBACK *p_cback;
+    tBTA_DM_SEARCH_CBACK    *p_cback;
+    tBTA_START_SCAN_CMPL_CBACK *p_start_scan_cback;
 } tBTA_DM_API_BLE_OBSERVE;
 
 typedef struct {
@@ -506,6 +507,7 @@ typedef struct {
     tBTM_BLE_ADV_CHNL_MAP   channel_map;
     tBTM_BLE_AFP            adv_filter_policy;
     tBLE_BD_ADDR            *p_dir_bda;
+    tBTA_START_ADV_CMPL_CBACK  *p_start_adv_cback;
 } tBTA_DM_API_BLE_ADV_PARAMS_ALL;
 
 
diff --git a/components/bt/bluedroid/bta/include/bta_api.h b/components/bt/bluedroid/bta/include/bta_api.h
index 1b97dc4fc..8e4b927aa 100644
--- a/components/bt/bluedroid/bta/include/bta_api.h
+++ b/components/bt/bluedroid/bta/include/bta_api.h
@@ -400,6 +400,8 @@ typedef struct {
 
 typedef void (tBTA_SET_ADV_DATA_CMPL_CBACK) (tBTA_STATUS status);
 
+typedef void (tBTA_START_ADV_CMPL_CBACK) (tBTA_STATUS status);
+
 /* advertising channel map */
 #define BTA_BLE_ADV_CHNL_37 BTM_BLE_ADV_CHNL_37
 #define BTA_BLE_ADV_CHNL_38 BTM_BLE_ADV_CHNL_38
@@ -1095,6 +1097,8 @@ typedef void (tBTA_BLE_SCAN_SETUP_CBACK) (tBTA_BLE_BATCH_SCAN_EVT evt,
         tBTA_DM_BLE_REF_VALUE ref_value,
         tBTA_STATUS status);
 
+typedef void (tBTA_START_SCAN_CMPL_CBACK) (tBTA_STATUS status); 
+
 typedef void (tBTA_BLE_TRACK_ADV_CMPL_CBACK)(int action, tBTA_STATUS status,
         tBTA_DM_BLE_PF_AVBL_SPACE avbl_space,
         tBTA_DM_BLE_REF_VALUE ref_value);
@@ -1891,7 +1895,7 @@ extern void BTA_DmSetBleAdvParams (UINT16 adv_int_min, UINT16 adv_int_max,
 extern void BTA_DmSetBleAdvParamsAll (UINT16 adv_int_min, UINT16 adv_int_max,
                                       UINT8 adv_type, tBLE_ADDR_TYPE addr_type_own,
                                       tBTM_BLE_ADV_CHNL_MAP chnl_map, tBTM_BLE_AFP adv_fil_pol,
-                                      tBLE_BD_ADDR *p_dir_bda);
+                                      tBLE_BD_ADDR *p_dir_bda, tBTA_START_ADV_CMPL_CBACK p_start_adv_cb);
 
 
 /*******************************************************************************
@@ -1997,7 +2001,8 @@ extern void BTA_DmSetEncryption(BD_ADDR bd_addr, tBTA_TRANSPORT transport,
 **
 *******************************************************************************/
 extern void BTA_DmBleObserve(BOOLEAN start, UINT8 duration,
-                             tBTA_DM_SEARCH_CBACK *p_results_cb);
+                             tBTA_DM_SEARCH_CBACK *p_results_cb,
+                             tBTA_START_SCAN_CMPL_CBACK *p_start_scan_cb);
 
 extern void BTA_DmBleStopAdvertising(void);
 
diff --git a/components/bt/bluedroid/btc/profile/std/gap/btc_gap_ble.c b/components/bt/bluedroid/btc/profile/std/gap/btc_gap_ble.c
index 339ff6842..8fea801b0 100644
--- a/components/bt/bluedroid/btc/profile/std/gap/btc_gap_ble.c
+++ b/components/bt/bluedroid/btc/profile/std/gap/btc_gap_ble.c
@@ -367,7 +367,26 @@ static void btc_ble_set_scan_rsp_data_raw(uint8_t *raw_scan_rsp, uint32_t raw_sc
     BTA_DmBleSetScanRspRaw(raw_scan_rsp, raw_scan_rsp_len, p_scan_rsp_data_cback);
 }
 
-static void btc_ble_start_advertising (esp_ble_adv_params_t *ble_adv_params)
+static void btc_start_adv_callback(tBTA_STATUS status)
+{
+    esp_ble_gap_cb_param_t param;
+    bt_status_t ret;
+    btc_msg_t msg;
+
+    msg.sig = BTC_SIG_API_CB;
+    msg.pid = BTC_PID_GAP_BLE;
+    msg.act = ESP_GAP_BLE_ADV_START_COMPLETE_EVT;
+    param.adv_start_cmpl.status = status;
+
+    ret = btc_transfer_context(&msg, &param,
+                               sizeof(esp_ble_gap_cb_param_t), NULL);
+
+    if (ret != BT_STATUS_SUCCESS) {
+        LOG_ERROR("%s btc_transfer_context failed\n", __func__);
+    }
+}
+
+static void btc_ble_start_advertising (esp_ble_adv_params_t *ble_adv_params, tBTA_START_ADV_CMPL_CBACK start_adv_cback)
 {
     tBLE_BD_ADDR peer_addr;
 
@@ -398,7 +417,8 @@ static void btc_ble_start_advertising (esp_ble_adv_params_t *ble_adv_params)
                              ble_adv_params->own_addr_type,
                              ble_adv_params->channel_map,
                              ble_adv_params->adv_filter_policy,
-                             &peer_addr);
+                             &peer_addr,
+                             start_adv_cback);
 }
 
 
@@ -487,12 +507,33 @@ static void btc_search_callback(tBTA_DM_SEARCH_EVT event, tBTA_DM_SEARCH *p_data
     btc_transfer_context(&msg, &param, sizeof(esp_ble_gap_cb_param_t), NULL);
 }
 
-
-static void btc_ble_start_scanning(uint8_t duration, tBTA_DM_SEARCH_CBACK *results_cb)
+static void btc_start_scan_callback(tBTA_STATUS status)
 {
-    if ((duration != 0) && (results_cb != NULL)) {
+    esp_ble_gap_cb_param_t param;
+    bt_status_t ret;
+    btc_msg_t msg;
+
+    msg.sig = BTC_SIG_API_CB;
+    msg.pid = BTC_PID_GAP_BLE;
+    msg.act = ESP_GAP_BLE_SCAN_START_COMPLETE_EVT;
+    param.scan_start_cmpl.status = status;
+
+
+    ret = btc_transfer_context(&msg, &param,
+                               sizeof(esp_ble_gap_cb_param_t), NULL);
+
+    if (ret != BT_STATUS_SUCCESS) {
+        LOG_ERROR("%s btc_transfer_context failed\n", __func__);
+    }
+}
+
+static void btc_ble_start_scanning(uint8_t duration,
+                                   tBTA_DM_SEARCH_CBACK *results_cb,
+                                   tBTA_START_SCAN_CMPL_CBACK *start_scan_cb)
+{
+    if ((duration != 0) && (results_cb != NULL) && (start_scan_cb != NULL)) {
         ///Start scan the device
-        BTA_DmBleObserve(true, duration, results_cb);
+        BTA_DmBleObserve(true, duration, results_cb, start_scan_cb);
     } else {
         LOG_ERROR("The scan duration or p_results_cb invalid\n");
     }
@@ -501,7 +542,7 @@ static void btc_ble_start_scanning(uint8_t duration, tBTA_DM_SEARCH_CBACK *resul
 static void btc_ble_stop_scanning(void)
 {
     uint8_t duration = 0;
-    BTA_DmBleObserve(false, duration, NULL);
+    BTA_DmBleObserve(false, duration, NULL, NULL);
 }
 
 
@@ -576,6 +617,12 @@ void btc_gap_ble_cb_handler(btc_msg_t *msg)
     case ESP_GAP_BLE_SCAN_RSP_DATA_RAW_SET_COMPLETE_EVT:
         btc_gap_ble_cb_to_app(ESP_GAP_BLE_SCAN_RSP_DATA_RAW_SET_COMPLETE_EVT, param);
         break;
+    case ESP_GAP_BLE_ADV_START_COMPLETE_EVT:
+        btc_gap_ble_cb_to_app(ESP_GAP_BLE_ADV_START_COMPLETE_EVT, param);
+        break;
+    case ESP_GAP_BLE_SCAN_START_COMPLETE_EVT:
+        btc_gap_ble_cb_to_app(ESP_GAP_BLE_SCAN_START_COMPLETE_EVT, param);
+        break;
     default:
         break;
 
@@ -695,13 +742,13 @@ void btc_gap_ble_call_handler(btc_msg_t *msg)
         btc_ble_set_scan_params(&arg->set_scan_param.scan_params, btc_scan_params_callback);
         break;
     case BTC_GAP_BLE_ACT_START_SCAN:
-        btc_ble_start_scanning(arg->start_scan.duration, btc_search_callback);
+        btc_ble_start_scanning(arg->start_scan.duration, btc_search_callback, btc_start_scan_callback);
         break;
     case BTC_GAP_BLE_ACT_STOP_SCAN:
         btc_ble_stop_scanning();
         break;
     case BTC_GAP_BLE_ACT_START_ADV:
-        btc_ble_start_advertising(&arg->start_adv.adv_params);
+        btc_ble_start_advertising(&arg->start_adv.adv_params, btc_start_adv_callback);
         break;
     case BTC_GAP_BLE_ACT_STOP_ADV:
         btc_ble_stop_advertising();
diff --git a/components/bt/bluedroid/stack/btm/btm_ble_gap.c b/components/bt/bluedroid/stack/btm/btm_ble_gap.c
index 4cfce3b66..07c63b496 100644
--- a/components/bt/bluedroid/stack/btm/btm_ble_gap.c
+++ b/components/bt/bluedroid/stack/btm/btm_ble_gap.c
@@ -2935,14 +2935,18 @@ tBTM_STATUS btm_ble_start_scan(void)
     tBTM_BLE_INQ_CB *p_inq = &btm_cb.ble_ctr_cb.inq_var;
     tBTM_STATUS status = BTM_CMD_STARTED;
 
-    /* start scan, disable duplicate filtering */
-    if (!btsnd_hcic_ble_set_scan_enable (BTM_BLE_SCAN_ENABLE, p_inq->scan_duplicate_filter)) {
+    if (p_inq->adv_mode != BTM_BLE_ADV_DISABLE) {
         status = BTM_NO_RESOURCES;
     } else {
-        if (p_inq->scan_type == BTM_BLE_SCAN_MODE_ACTI) {
-            btm_ble_set_topology_mask(BTM_BLE_STATE_ACTIVE_SCAN_BIT);
+        /* start scan, disable duplicate filtering */
+        if (!btsnd_hcic_ble_set_scan_enable (BTM_BLE_SCAN_ENABLE, p_inq->scan_duplicate_filter)) {
+            status = BTM_NO_RESOURCES;
         } else {
-            btm_ble_set_topology_mask(BTM_BLE_STATE_PASSIVE_SCAN_BIT);
+            if (p_inq->scan_type == BTM_BLE_SCAN_MODE_ACTI) {
+                btm_ble_set_topology_mask(BTM_BLE_STATE_ACTIVE_SCAN_BIT);
+            } else {
+                btm_ble_set_topology_mask(BTM_BLE_STATE_PASSIVE_SCAN_BIT);
+            }
         }
     }
     return status;
@@ -2961,15 +2965,17 @@ void btm_ble_stop_scan(void)
 {
     BTM_TRACE_EVENT ("btm_ble_stop_scan ");
 
-    /* Clear the inquiry callback if set */
-    btm_cb.ble_ctr_cb.inq_var.scan_type = BTM_BLE_SCAN_MODE_NONE;
+    if (btm_cb.ble_ctr_cb.inq_var.adv_mode == BTM_BLE_ADV_DISABLE) {
+        /* Clear the inquiry callback if set */
+        btm_cb.ble_ctr_cb.inq_var.scan_type = BTM_BLE_SCAN_MODE_NONE;
 
-    /* stop discovery now */
-    btsnd_hcic_ble_set_scan_enable (BTM_BLE_SCAN_DISABLE, BTM_BLE_DUPLICATE_ENABLE);
+        /* stop discovery now */
+        btsnd_hcic_ble_set_scan_enable (BTM_BLE_SCAN_DISABLE, BTM_BLE_DUPLICATE_ENABLE);
 
-    btm_update_scanner_filter_policy(SP_ADV_ALL);
+        btm_update_scanner_filter_policy(SP_ADV_ALL);
 
-    btm_cb.ble_ctr_cb.wl_state &= ~BTM_BLE_WL_SCAN;
+        btm_cb.ble_ctr_cb.wl_state &= ~BTM_BLE_WL_SCAN;
+    }
 }
 /*******************************************************************************
 **
@@ -3089,9 +3095,15 @@ static BOOLEAN btm_ble_adv_states_operation(BTM_TOPOLOGY_FUNC_PTR *p_handler, UI
 *******************************************************************************/
 tBTM_STATUS btm_ble_start_adv(void)
 {
+    tBTM_BLE_CB *p_ble_cb = & btm_cb.ble_ctr_cb;
     tBTM_BLE_INQ_CB *p_cb = &btm_cb.ble_ctr_cb.inq_var;
     tBTM_STATUS     rt = BTM_NO_RESOURCES;
     BTM_TRACE_EVENT ("btm_ble_start_adv\n");
+
+    if (BTM_BLE_IS_OBS_ACTIVE(p_ble_cb->scan_activity)) {
+        return BTM_NO_RESOURCES;
+    }
+
     if (!btm_ble_adv_states_operation (btm_ble_topology_check, p_cb->evt_type)) {
         return BTM_WRONG_MODE;
     }
@@ -3133,10 +3145,12 @@ tBTM_STATUS btm_ble_start_adv(void)
 *******************************************************************************/
 tBTM_STATUS btm_ble_stop_adv(void)
 {
+    tBTM_BLE_CB *p_ble_cb = & btm_cb.ble_ctr_cb;
     tBTM_BLE_INQ_CB *p_cb = &btm_cb.ble_ctr_cb.inq_var;
     tBTM_STATUS rt = BTM_SUCCESS;
 
-    if (p_cb->adv_mode == BTM_BLE_ADV_ENABLE) {
+    if (p_cb->adv_mode == BTM_BLE_ADV_ENABLE
+            && !BTM_BLE_IS_OBS_ACTIVE(p_ble_cb->scan_activity)) {
         if (btsnd_hcic_ble_set_adv_enable (BTM_BLE_ADV_DISABLE)) {
             p_cb->fast_adv_on = FALSE;
             p_cb->adv_mode = BTM_BLE_ADV_DISABLE;
diff --git a/components/bt/bluedroid/stack/gatt/gatt_db.c b/components/bt/bluedroid/stack/gatt/gatt_db.c
index 03919d483..bb9bfc5f7 100644
--- a/components/bt/bluedroid/stack/gatt/gatt_db.c
+++ b/components/bt/bluedroid/stack/gatt/gatt_db.c
@@ -597,11 +597,14 @@ UINT16 gatts_add_char_descr (tGATT_SVC_DB *p_db, tGATT_PERM perm,
             }
             p_char_dscptr->p_value->attr_val.attr_len = attr_val->attr_len;
             p_char_dscptr->p_value->attr_val.attr_max_len  = attr_val->attr_max_len;
-            if (attr_val->attr_val != NULL) {
+            if (attr_val->attr_max_len != 0) {
                 p_char_dscptr->p_value->attr_val.attr_val = GKI_getbuf(attr_val->attr_max_len);
                 if (p_char_dscptr->p_value->attr_val.attr_val != NULL) {
                     memset(p_char_dscptr->p_value->attr_val.attr_val, 0, attr_val->attr_max_len);
-                    memcpy(p_char_dscptr->p_value->attr_val.attr_val, attr_val->attr_val, attr_val->attr_len);
+                    if(attr_val->attr_val != NULL) {
+                        memcpy(p_char_dscptr->p_value->attr_val.attr_val, 
+                               attr_val->attr_val, attr_val->attr_len);
+                    }
                 }
             }
         }
@@ -873,7 +876,7 @@ tGATT_STATUS gatts_write_attr_value_by_handle(tGATT_SVC_DB *p_db,
                 }
 
                 if (p_attr->p_value != NULL && (p_attr->p_value->attr_val.attr_max_len >=
-                                                offset + len)) {
+                                                offset + len) && p_attr->p_value->attr_val.attr_val != NULL) {
                     memcpy(p_attr->p_value->attr_val.attr_val + offset, p_value, len);
                     p_attr->p_value->attr_val.attr_len = len + offset;
                     return GATT_SUCCESS;
diff --git a/components/bt/bt.c b/components/bt/bt.c
index 6a81d11ac..4943b9acb 100644
--- a/components/bt/bt.c
+++ b/components/bt/bt.c
@@ -32,9 +32,14 @@
 
 #if CONFIG_BT_ENABLED
 
+/* Bluetooth system and controller config */
+#define BTDM_CFG_BT_EM_RELEASE      (1<<0)
+#define BTDM_CFG_BT_DATA_RELEASE    (1<<1)
+/* Other reserved for future */
+
 /* not for user call, so don't put to include file */
 extern void btdm_osi_funcs_register(void *osi_funcs);
-extern void btdm_controller_init(void);
+extern void btdm_controller_init(uint32_t config_mask);
 extern void btdm_controller_schedule(void);
 extern void btdm_controller_deinit(void);
 extern int btdm_controller_enable(esp_bt_mode_t mode);
@@ -154,11 +159,25 @@ void esp_vhci_host_register_callback(const esp_vhci_host_callback_t *callback)
     API_vhci_host_register_callback((const vhci_host_callback_t *)callback);
 }
 
+static uint32_t btdm_config_mask_load(void)
+{
+    uint32_t mask = 0x0;
+
+#ifdef CONFIG_BT_DRAM_RELEASE
+    mask |= (BTDM_CFG_BT_EM_RELEASE | BTDM_CFG_BT_DATA_RELEASE);
+#endif
+    return mask;
+}
+
 static void bt_controller_task(void *pvParam)
 {
+    uint32_t btdm_cfg_mask = 0;
+
     btdm_osi_funcs_register(&osi_funcs);
 
-    btdm_controller_init();
+    btdm_cfg_mask = btdm_config_mask_load();
+    btdm_controller_init(btdm_cfg_mask);
+
     btdm_controller_status = ESP_BT_CONTROLLER_STATUS_INITED;
 
     /* Loop */
diff --git a/components/bt/lib b/components/bt/lib
index dbac82b5c..9f9f6a004 160000
--- a/components/bt/lib
+++ b/components/bt/lib
@@ -1 +1 @@
-Subproject commit dbac82b5c2694f2639161b0a2b3c0bd8c7d3efc5
+Subproject commit 9f9f6a004e42519f54555c42a037b8ef25bf2238
diff --git a/components/driver/spi_master.c b/components/driver/spi_master.c
index f37f7aaf1..17a68c323 100644
--- a/components/driver/spi_master.c
+++ b/components/driver/spi_master.c
@@ -600,7 +600,7 @@ static void IRAM_ATTR spi_intr(void *arg)
             } else {
                 data=trans->rx_buffer;
             }
-            if (trans->rxlength<THRESH_DMA_TRANS) {
+            if (trans->rxlength <= THRESH_DMA_TRANS) {
                 //No need for DMA; we'll copy the result out of the work registers directly later.
             } else {
                 host->hw->user.usr_miso_highpart=0;
@@ -625,9 +625,9 @@ static void IRAM_ATTR spi_intr(void *arg)
             } else {
                 data=(uint32_t *)trans->tx_buffer;
             }
-            if (trans->rxlength < 8*32) {
+            if (trans->length <= THRESH_DMA_TRANS) {
                 //No need for DMA.
-                for (int x=0; x < trans->rxlength; x+=32) {
+                for (int x=0; x < trans->length; x+=32) {
                     //Use memcpy to get around alignment issues for txdata
                     uint32_t word;
                     memcpy(&word, &data[x/32], 4);
@@ -656,7 +656,7 @@ static void IRAM_ATTR spi_intr(void *arg)
             host->hw->addr=trans->address & 0xffffffff;
         }
         host->hw->user.usr_mosi=(trans->tx_buffer==NULL)?0:1;
-        host->hw->user.usr_miso=(trans->tx_buffer==NULL)?0:1;
+        host->hw->user.usr_miso=(trans->rx_buffer==NULL)?0:1;
 
         //Call pre-transmission callback, if any
         if (dev->cfg.pre_cb) dev->cfg.pre_cb(trans);
diff --git a/components/esp32/deep_sleep.c b/components/esp32/deep_sleep.c
index 3eef7ca29..4d672402e 100644
--- a/components/esp32/deep_sleep.c
+++ b/components/esp32/deep_sleep.c
@@ -22,6 +22,7 @@
 #include "rom/uart.h"
 #include "soc/cpu.h"
 #include "soc/rtc_cntl_reg.h"
+#include "soc/sens_reg.h"
 #include "soc/dport_reg.h"
 #include "driver/rtc_io.h"
 #include "freertos/FreeRTOS.h"
@@ -111,6 +112,13 @@ void IRAM_ATTR esp_deep_sleep_start()
     // Decide which power domains can be powered down
     uint32_t pd_flags = get_power_down_flags();
 
+    // Shut down parts of RTC which may have been left enabled by the wireless drivers
+    CLEAR_PERI_REG_MASK(RTC_CNTL_ANA_CONF_REG,
+            RTC_CNTL_CKGEN_I2C_PU | RTC_CNTL_PLL_I2C_PU |
+            RTC_CNTL_RFRX_PBUS_PU | RTC_CNTL_TXRF_I2C_PU);
+
+    SET_PERI_REG_BITS(SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_SAR_M, 0, SENS_FORCE_XPD_SAR_S);
+
     // Configure pins for external wakeup
     if (s_config.wakeup_triggers & EXT_EVENT0_TRIG_EN) {
         ext0_wakeup_prepare();
diff --git a/components/esp32/heap_alloc_caps.c b/components/esp32/heap_alloc_caps.c
index a4ff870f3..7d2a26e64 100644
--- a/components/esp32/heap_alloc_caps.c
+++ b/components/esp32/heap_alloc_caps.c
@@ -193,8 +193,14 @@ void heap_alloc_caps_init() {
     disable_mem_region((void*)0x3ffe0000, (void*)0x3ffe8000); //knock out ROM data region
 
 #if CONFIG_BT_ENABLED
+#if CONFIG_BT_DRAM_RELEASE
+    disable_mem_region((void*)0x3ffb0000, (void*)0x3ffb3000); //knock out BT data region
+    disable_mem_region((void*)0x3ffb8000, (void*)0x3ffbbb28); //knock out BT data region
+    disable_mem_region((void*)0x3ffbdb28, (void*)0x3ffc0000); //knock out BT data region
+#else
     disable_mem_region((void*)0x3ffb0000, (void*)0x3ffc0000); //knock out BT data region
 #endif
+#endif
 
 #if CONFIG_MEMMAP_TRACEMEM
 #if CONFIG_MEMMAP_TRACEMEM_TWOBANKS
diff --git a/components/esp32/include/esp_deep_sleep.h b/components/esp32/include/esp_deep_sleep.h
index a6251e2de..aba74b30d 100644
--- a/components/esp32/include/esp_deep_sleep.h
+++ b/components/esp32/include/esp_deep_sleep.h
@@ -164,6 +164,14 @@ void esp_deep_sleep_start() __attribute__((noreturn));
  * Call to this function is equivalent to a call to esp_deep_sleep_enable_timer_wakeup
  * followed by a call to esp_deep_sleep_start.
  *
+ * esp_deep_sleep does not shut down WiFi, BT, and higher level protocol
+ * connections gracefully.
+ * Make sure relevant WiFi and BT stack functions are called to close any
+ * connections and deinitialize the peripherals. These include:
+ *     - esp_bluedroid_disable
+ *     - esp_bt_controller_disable
+ *     - esp_wifi_stop
+ *
  * This function does not return.
  *
  * @param time_in_us  deep-sleep time, unit: microsecond
diff --git a/components/esp32/include/esp_wifi.h b/components/esp32/include/esp_wifi.h
index 0f7e2996e..9f3b1ed70 100755
--- a/components/esp32/include/esp_wifi.h
+++ b/components/esp32/include/esp_wifi.h
@@ -422,6 +422,7 @@ esp_err_t esp_wifi_get_bandwidth(wifi_interface_t ifx, wifi_bandwidth_t *bw);
   * @brief     Set primary/secondary channel of ESP32
   *
   * @attention 1. This is a special API for sniffer
+  * @attention 2. This API should be called after esp_wifi_start() or esp_wifi_set_promiscuous()
   *
   * @param     primary  for HT20, primary is the channel number, for HT40, primary is the primary channel
   * @param     second   for HT20, second is ignored, for HT40, second is the second channel
diff --git a/components/esp32/ld/esp32.common.ld b/components/esp32/ld/esp32.common.ld
index 43775a6c4..bc28e5ca9 100644
--- a/components/esp32/ld/esp32.common.ld
+++ b/components/esp32/ld/esp32.common.ld
@@ -84,6 +84,7 @@ SECTIONS
     *libphy.a:(.literal .text .literal.* .text.*)
     *librtc.a:(.literal .text .literal.* .text.*)
     *librtc_clk.a:(.literal .text .literal.* .text.*)
+    *libpp.a:pp.o(.literal .text .literal.* .text.*)
     *libpp.a:lmac.o(.literal .text .literal.* .text.*)
     *libpp.a:wdev.o(.literal .text .literal.* .text.*)
     *libcore.a:ets_timer.o(.literal .text .literal.* .text.*)
diff --git a/components/esp32/lib b/components/esp32/lib
index ed85cf915..28c6ee924 160000
--- a/components/esp32/lib
+++ b/components/esp32/lib
@@ -1 +1 @@
-Subproject commit ed85cf9156f2ef358c29d07fb849a73c5758eecb
+Subproject commit 28c6ee924ca6efc71bb77dcb040efd07d4d8a000
diff --git a/components/fatfs/src/vfs_fat_sdmmc.c b/components/fatfs/src/vfs_fat_sdmmc.c
index e5956dd7b..77620f5d8 100644
--- a/components/fatfs/src/vfs_fat_sdmmc.c
+++ b/components/fatfs/src/vfs_fat_sdmmc.c
@@ -39,14 +39,19 @@ esp_err_t esp_vfs_fat_sdmmc_mount(const char* base_path,
     sdmmc_host_init();
 
     // enable card slot
-    sdmmc_host_init_slot(host_config->slot, slot_config);
+    esp_err_t err = sdmmc_host_init_slot(host_config->slot, slot_config);
+    if (err != ESP_OK) {
+        return err;
+    }
+
     s_card = malloc(sizeof(sdmmc_card_t));
     if (s_card == NULL) {
-        return ESP_ERR_NO_MEM;
+        err = ESP_ERR_NO_MEM;
+        goto fail;
     }
 
     // probe and initialize card
-    esp_err_t err = sdmmc_card_init(host_config, s_card);
+    err = sdmmc_card_init(host_config, s_card);
     if (err != ESP_OK) {
         ESP_LOGD(TAG, "sdmmc_card_init failed 0x(%x)", err);
         goto fail;
@@ -104,6 +109,7 @@ esp_err_t esp_vfs_fat_sdmmc_mount(const char* base_path,
     return ESP_OK;
 
 fail:
+    sdmmc_host_deinit();
     free(workbuf);
     esp_vfs_unregister(base_path);
     free(s_card);
diff --git a/components/fatfs/test/test_fatfs.c b/components/fatfs/test/test_fatfs.c
index 4f6482740..d518652bc 100644
--- a/components/fatfs/test/test_fatfs.c
+++ b/components/fatfs/test/test_fatfs.c
@@ -52,6 +52,25 @@ static void create_file_with_text(const char* name, const char* text)
     TEST_ASSERT_EQUAL(0, fclose(f));
 }
 
+TEST_CASE("Mount fails cleanly without card inserted", "[fatfs][ignore]")
+{
+    HEAP_SIZE_CAPTURE();
+    sdmmc_host_t host = SDMMC_HOST_DEFAULT();
+    sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
+    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
+        .format_if_mount_failed = false,
+        .max_files = 5
+    };
+
+    for (int i = 0; i < 3; ++i) {
+        printf("Initializing card, attempt %d ", i);
+        esp_err_t err = esp_vfs_fat_sdmmc_mount("/sdcard", &host, &slot_config, &mount_config, NULL);
+        printf(" err=%d\n", err);
+        TEST_ESP_ERR(ESP_FAIL, err);
+    }
+    HEAP_SIZE_CHECK(0);
+}
+
 TEST_CASE("can create and write file on sd card", "[fatfs][ignore]")
 {
     HEAP_SIZE_CAPTURE();
diff --git a/components/freertos/tasks.c b/components/freertos/tasks.c
index 02d184287..0804bb3eb 100644
--- a/components/freertos/tasks.c
+++ b/components/freertos/tasks.c
@@ -1056,11 +1056,15 @@ static void prvAddNewTaskToReadyList( TCB_t *pxNewTCB, TaskFunction_t pxTaskCode
 	taskENTER_CRITICAL(&xTaskQueueMutex);
 	{
 		uxCurrentNumberOfTasks++;
-		if( pxCurrentTCB[ xPortGetCoreID() ] == NULL )
+		//If the task has no affinity and nothing is scheduled on this core, just throw it this core.
+		//If it has affinity, throw it on the core that needs it if nothing is already scheduled there.
+		BaseType_t xMyCore = xCoreID;
+		if ( xMyCore == tskNO_AFFINITY) xMyCore = xPortGetCoreID();
+		if( pxCurrentTCB[ xMyCore ] == NULL )
 		{
 			/* There are no other tasks, or all the other tasks are in
 			the suspended state - make this the current task. */
-			pxCurrentTCB[ xPortGetCoreID() ] = pxNewTCB;
+			pxCurrentTCB[ xMyCore ] = pxNewTCB;
 
 			if( uxCurrentNumberOfTasks == ( UBaseType_t ) 1 )
 			{
@@ -1121,12 +1125,13 @@ static void prvAddNewTaskToReadyList( TCB_t *pxNewTCB, TaskFunction_t pxTaskCode
 
 		portSETUP_TCB( pxNewTCB );
 	}
-        curTCB =  pxCurrentTCB[ xPortGetCoreID() ];
+
 	taskEXIT_CRITICAL(&xTaskQueueMutex);
 
 	if( xSchedulerRunning != pdFALSE )
 	{
 	       taskENTER_CRITICAL(&xTaskQueueMutex);
+		curTCB = pxCurrentTCB[ xPortGetCoreID() ];
 		/* Scheduler is running. If the created task is of a higher priority than an executing task
 	       then it should run now.
 		   ToDo: This only works for the current core. If a task is scheduled on an other processor,
@@ -1141,7 +1146,7 @@ static void prvAddNewTaskToReadyList( TCB_t *pxNewTCB, TaskFunction_t pxTaskCode
 			*/
 			if( tskCAN_RUN_HERE( xCoreID ) && curTCB->uxPriority < pxNewTCB->uxPriority )
 			{
-				taskYIELD_IF_USING_PREEMPTION();
+				taskYIELD_IF_USING_PREEMPTION_MUX(&xTaskQueueMutex);
 			}
 			else if( xCoreID != xPortGetCoreID() ) {
 				taskYIELD_OTHER_CORE(xCoreID, pxNewTCB->uxPriority);
@@ -2659,11 +2664,13 @@ BaseType_t xSwitchRequired = pdFALSE;
 
 void vTaskSwitchContext( void )
 {
-	tskTCB * pxTCB;
-	//This can be called both from IRQ as well as normal context, so we can't 
-	//use taskENTER_CRITICAL() here. Instead, save the irq status and disable
-	//IRQs, so we can use taskENTER_CRITICAL_ISR and friends.
+	//Note: This can be called from interrupt context as well as from non-interrupt context (voluntary yield). The
+	//taskENTER_CRITICAL/taskEXIT_CRITICAL is modified to work in both scenarios for the ESP32, so we can freely use
+	//them here. However, in case of a voluntary yield, a nonvoluntary yield can still happen *during* the voluntary
+	//yield. Disabling interrupts using portENTER_CRITICAL_NESTED puts a stop to this and makes the rest of the code a 
+	//bit neater.
 	int irqstate=portENTER_CRITICAL_NESTED();
+	tskTCB * pxTCB;
 	if( uxSchedulerSuspended[ xPortGetCoreID() ] != ( UBaseType_t ) pdFALSE )
 	{
 		/* The scheduler is currently suspended - do not allow a context
diff --git a/components/partition_table/gen_esp32part.py b/components/partition_table/gen_esp32part.py
index 56bfe29fb..d57059f4e 100755
--- a/components/partition_table/gen_esp32part.py
+++ b/components/partition_table/gen_esp32part.py
@@ -4,9 +4,12 @@
 #
 # Converts partition tables to/from CSV and binary formats.
 #
-# See the sdkng README.md file for details about how to use this tool.
-import struct
+# See http://esp-idf.readthedocs.io/en/latest/partition-tables.html for explanation of
+# partition table structure and uses.
 import argparse
+import os
+import re
+import struct
 import sys
 
 MAX_PARTITION_LENGTH = 0xC00   # 3K for partition data (96 entries) leaves 1K in a 4K sector for signature
@@ -163,7 +166,13 @@ class PartitionDefinition(object):
     def from_csv(cls, line):
         """ Parse a line from the CSV """
         line_w_defaults = line + ",,,,"  # lazy way to support default fields
-        fields = [ f.strip() for f in line_w_defaults.split(",") ]
+        def expand_vars(f):
+            f = os.path.expandvars(f)
+            m = re.match(r'(?<!\\)\$([A-Za-z_][A-Za-z0-9_]*)', f)
+            if m:
+                raise InputError("unknown variable '%s'" % m.group(1))
+            return f
+        fields = [ expand_vars(f.strip()) for f in line_w_defaults.split(",") ]
 
         res = PartitionDefinition()
         res.name = fields[0]
@@ -346,5 +355,5 @@ if __name__ == '__main__':
     try:
         main()
     except InputError as e:
-        print(e)
+        print >>sys.stderr, e
         sys.exit(2)
diff --git a/components/spi_flash/cache_utils.c b/components/spi_flash/cache_utils.c
index df9d18c44..5e880ab49 100644
--- a/components/spi_flash/cache_utils.c
+++ b/components/spi_flash/cache_utils.c
@@ -205,16 +205,16 @@ void spi_flash_op_unlock()
 
 void IRAM_ATTR spi_flash_disable_interrupts_caches_and_other_cpu()
 {
-    esp_intr_noniram_disable();
     spi_flash_op_lock();
+    esp_intr_noniram_disable();
     spi_flash_disable_cache(0, &s_flash_op_cache_state[0]);
 }
 
 void IRAM_ATTR spi_flash_enable_interrupts_caches_and_other_cpu()
 {
     spi_flash_restore_cache(0, s_flash_op_cache_state[0]);
-    spi_flash_op_unlock();
     esp_intr_noniram_enable();
+    spi_flash_op_unlock();
 }
 
 void IRAM_ATTR spi_flash_disable_interrupts_caches_and_other_cpu_no_os()
diff --git a/components/spi_flash/flash_ops.c b/components/spi_flash/flash_ops.c
index 3581b3414..324c02a3d 100644
--- a/components/spi_flash/flash_ops.c
+++ b/components/spi_flash/flash_ops.c
@@ -202,7 +202,9 @@ esp_err_t IRAM_ATTR spi_flash_write(size_t dst, const void *srcv, size_t size)
     size_t mid_size = (size - left_size) & ~3U;
     size_t right_off = left_size + mid_size;
     size_t right_size = size - mid_size - left_size;
+    spi_flash_guard_start();
     rc = spi_flash_unlock();
+    spi_flash_guard_end();
     if (rc != SPI_FLASH_RESULT_OK) {
         goto out;
     }
@@ -289,7 +291,9 @@ esp_err_t IRAM_ATTR spi_flash_write_encrypted(size_t dest_addr, const void *src,
     COUNTER_START();
     spi_flash_disable_interrupts_caches_and_other_cpu();
     SpiFlashOpResult rc;
+    spi_flash_guard_start();
     rc = spi_flash_unlock();
+    spi_flash_guard_end();
     spi_flash_enable_interrupts_caches_and_other_cpu();
 
     if (rc == SPI_FLASH_RESULT_OK) {
diff --git a/components/spi_flash/test/test_spi_flash.c b/components/spi_flash/test/test_spi_flash.c
index 90d0cc1fd..597568ec6 100644
--- a/components/spi_flash/test/test_spi_flash.c
+++ b/components/spi_flash/test/test_spi_flash.c
@@ -65,19 +65,24 @@ static void flash_test_task(void *arg)
 TEST_CASE("flash write and erase work both on PRO CPU and on APP CPU", "[spi_flash][ignore]")
 {
     SemaphoreHandle_t done = xSemaphoreCreateCounting(4, 0);
-    struct flash_test_ctx ctx[4] = {
+    struct flash_test_ctx ctx[] = {
             { .offset = 0x100 + 6, .done = done },
             { .offset = 0x100 + 7, .done = done },
             { .offset = 0x100 + 8, .done = done },
+#ifndef CONFIG_FREERTOS_UNICORE
             { .offset = 0x100 + 9, .done = done }
+#endif
     };
 
-    xTaskCreatePinnedToCore(flash_test_task, "1", 2048, &ctx[0], 3, NULL, 0);
-    xTaskCreatePinnedToCore(flash_test_task, "2", 2048, &ctx[1], 3, NULL, 1);
-    xTaskCreatePinnedToCore(flash_test_task, "3", 2048, &ctx[2], 3, NULL, tskNO_AFFINITY);
-    xTaskCreatePinnedToCore(flash_test_task, "4", 2048, &ctx[3], 3, NULL, tskNO_AFFINITY);
+    xTaskCreatePinnedToCore(flash_test_task, "t0", 2048, &ctx[0], 3, NULL, 0);
+    xTaskCreatePinnedToCore(flash_test_task, "t1", 2048, &ctx[1], 3, NULL, tskNO_AFFINITY);
+    xTaskCreatePinnedToCore(flash_test_task, "t2", 2048, &ctx[2], 3, NULL, tskNO_AFFINITY);
+#ifndef CONFIG_FREERTOS_UNICORE
+    xTaskCreatePinnedToCore(flash_test_task, "t3", 2048, &ctx[3], 3, NULL, 1);
+#endif
 
-    for (int i = 0; i < 4; ++i) {
+    const size_t task_count = sizeof(ctx)/sizeof(ctx[0]);
+    for (int i = 0; i < task_count; ++i) {
         xSemaphoreTake(done, portMAX_DELAY);
         TEST_ASSERT_FALSE(ctx[i].fail);
     }
diff --git a/docs/api/bluetooth/esp_gap_ble.rst b/docs/api/bluetooth/esp_gap_ble.rst
index fea937630..41bffa095 100644
--- a/docs/api/bluetooth/esp_gap_ble.rst
+++ b/docs/api/bluetooth/esp_gap_ble.rst
@@ -93,6 +93,12 @@ Structures
 .. doxygenstruct:: esp_ble_gap_cb_param_t::ble_scan_rsp_data_raw_cmpl_evt_param
     :members:
 
+.. doxygenstruct:: esp_ble_gap_cb_param_t::ble_adv_start_cmpl_evt_param
+    :members:
+
+.. doxygenstruct:: esp_ble_gap_cb_param_t::ble_scan_start_cmpl_evt_param
+    :members:
+
 
 Functions
 ^^^^^^^^^
diff --git a/docs/build-system.rst b/docs/build-system.rst
index 0973eeb31..b3abbd28f 100644
--- a/docs/build-system.rst
+++ b/docs/build-system.rst
@@ -305,6 +305,17 @@ Second Level: Component Makefiles
 
 To better understand the component make process, have a read through the ``component_wrapper.mk`` file and some of the ``component.mk`` files included with esp-idf.
 
+Running Make Non-Interactively
+------------------------------
+
+When running ``make`` in a situation where you don't want interactive prompts (for example: inside an IDE or an automated build system) append ``BATCH_BUILD=1`` to the make arguments (or set it as an environment variable).
+
+Setting ``BATCH_BUILD`` implies the following:
+
+- Verbose output (same as ``V=1``, see below). If you don't want verbose output, also set ``V=0``.
+- If the project configuration is missing new configuration items (from new components or esp-idf updates) then the project use the default values, instead of prompting the user for each item.
+- If the build system needs to invoke ``menuconfig``, an error is printed and the build fails.
+
 Debugging The Make Process
 --------------------------
 
diff --git a/docs/eclipse-setup-windows.rst b/docs/eclipse-setup-windows.rst
new file mode 100644
index 000000000..aeb011c0c
--- /dev/null
+++ b/docs/eclipse-setup-windows.rst
@@ -0,0 +1,77 @@
+Eclipse IDE on Windows
+**********************
+
+Configuring Eclipse on Windows requires some different steps. The full configuration steps for Windows are shown below.
+
+(For OS X and Linux instructions, see the :doc:`Eclipse IDE page <eclipse-setup>`.)
+
+Installing Eclipse IDE
+======================
+
+Follow the steps under :ref:`Installing Eclipse IDE <eclipse-install-steps>` for all platforms.
+
+.. _eclipse-windows-setup:
+
+Setting up Eclipse on Windows
+=============================
+
+Once your new Eclipse installation launches, follow these steps:
+
+Import New Project
+------------------
+
+* Eclipse makes use of the Makefile support in ESP-IDF. This means you need to start by creating an ESP-IDF project. You can use the idf-template project from github, or open one of the examples in the esp-idf examples subdirectory.
+
+* Once Eclipse is running, choose File -> Import...
+
+* In the dialog that pops up, choose "C/C++" -> "Existing Code as Makefile Project" and click Next.
+
+* On the next page, enter "Existing Code Location" to be the directory of your IDF project. Don't specify the path to the ESP-IDF directory itself (that comes later). The directory you specify should contain a file named "Makefile" (the project Makefile).
+
+* On the same page, under "Toolchain for Indexer Settings" uncheck "Show only available toolchains that support this platform".
+
+* On the extended list that appears, choose "Cygwin GCC". Then click Finish.
+
+*Note: you may see warnings in the UI that Cygwin GCC Toolchain could not be found. This is OK, we're going to reconfigure Eclipse to find our toolchain.*
+
+Project Properties
+------------------
+
+* The new project will appear under Project Explorer. Right-click the project and choose Properties from the context menu.
+
+* Click on the "C/C++ Build" properties page (top-level):
+
+  * Uncheck "Use default build command" and enter this for the custom build command: ``python ${IDF_PATH}/tools/windows/eclipse_make.py``.
+
+* Click on the "Environment" properties page under "C/C++ Build":
+
+  * Click "Add..." and enter name ``BATCH_BUILD`` and value ``1``.
+
+  * Click "Add..." again, and enter name ``IDF_PATH``. The value should be the full path where ESP-IDF is installed. The IDF_PATH directory should be specified using forwards slashes not backslashes, ie *C:/Users/MyUser/Development/esp-idf*.
+
+  * Edit the PATH environment variable. Delete the existing value and replace it with ``C:\msys32\usr\bin;C:\msys32\mingw32\bin;C:\msys32\opt\xtensa-esp32-elf\bin`` (If you installed msys32 to a different directory then you'll need to change these paths to match).
+
+* Click on "C/C++ General" -> "Preprocessor Include Paths, Macros,etc." property page:
+
+  * Click the "Providers" tab
+
+     * In the list of providers, click "CDT GCC Built-in Compiler Settings Cygwin". Under "Command to get compiler specs", replace the text ``${COMMAND}`` at the beginning of the line with ``xtensa-esp32-elf-gcc``. This means the full "Command to get compiler specs" should be ``xtensa-esp32-elf-gcc ${FLAGS} -E -P -v -dD "${INPUTS}"``.
+
+     * In the list of providers, click "CDT GCC Build Output Parser" and type ``xtensa-esp32-elf-`` at the beginning of the Compiler command pattern. This means the full Compiler command pattern should be ``xtensa-esp32-elf-(g?cc)|([gc]\+\+)|(clang)``
+
+
+Building in Eclipse
+-------------------
+
+Continue from :ref:`Building in Eclipse <eclipse-build-project>` for all platforms.
+
+Technical Details
+=================
+
+**Of interest to Windows gurus or very curious parties, only.**
+
+Explanations of the technical reasons for some of these steps. You don't need to know this in order to use esp-idf with Eclipse on Windows, but it may be helpful background knowledge if you plan to do dig into the Eclipse support:
+
+* The xtensa-esp32-elf-gcc cross-compiler is *not* a Cygwin toolchain, even though we tell Eclipse that it is one. This is because msys2 uses Cygwin and supports Cygwin paths (of the type ``/c/blah`` instead of ``c:/blah`` or ``c:\\blah``). In particular, xtensa-esp32-elf-gcc reports to the Eclipse "built-in compiler settings" function that its built-in include directories are all under ``/usr/``, which is a Unix/Cygwin-style path that Eclipse otherwise can't resolve. By telling Eclipse the compiler is Cygwin, it resolves these paths internally using the ``cygpath`` utility.
+
+* The same problem occurs when parsing make output from esp-idf. Eclipse parses this output to find header directories, but it can't resolve include directories of the form ``/c/blah`` without using ``cygpath``. There is a heuristic that Eclipse Build Output Parser uses to determine whether it should call ``cygpath``, but for currently unknown reasons the esp-idf configuration doesn't trigger it. For this reason the ``eclipse_make.py`` wrapper script is used to call ``make`` and then use ``cygpath`` to process the output for Eclipse.
diff --git a/docs/eclipse-setup.rst b/docs/eclipse-setup.rst
index fbad93be6..140e81e17 100644
--- a/docs/eclipse-setup.rst
+++ b/docs/eclipse-setup.rst
@@ -1,6 +1,8 @@
 Build and Flash with Eclipse IDE
 ********************************
 
+.. _eclipse-install-steps:
+
 Installing Eclipse IDE
 ======================
 
@@ -8,10 +10,17 @@ The Eclipse IDE gives you a graphical integrated development environment for wri
 
 * Start by installing the esp-idf for your platform (see files in this directory with steps for Windows, OS X, Linux).
 
+* We suggest building a project from the command line first, to get a feel for how that process works. You also need to use the command line to configure your esp-idf project (via ``make menuconfig``), this is not currently supported inside Eclipse.
+
 * Download the Eclipse Installer for your platform from eclipse.org_.
 
 * When running the Eclipse Installer, choose "Eclipse for C/C++ Development" (in other places you'll see this referred to as CDT.)
 
+Windows Users
+=============
+
+Using ESP-IDF with Eclipse on Windows requires different configuration steps. :ref:`See the Eclipse IDE on Windows guide <eclipse-windows-setup>`.
+
 Setting up Eclipse
 ==================
 
@@ -20,13 +29,13 @@ Once your new Eclipse installation launches, follow these steps:
 Import New Project
 ------------------
 
-* Eclipse makes use of the Makefile support in ESP-IDF. This means you need to start by creating an ESP-IDF project. You can use the skeleton project from github.
+* Eclipse makes use of the Makefile support in ESP-IDF. This means you need to start by creating an ESP-IDF project. You can use the idf-template project from github, or open one of the examples in the esp-idf examples subdirectory.
 
 * Once Eclipse is running, choose File -> Import...
 
 * In the dialog that pops up, choose "C/C++" -> "Existing Code as Makefile Project" and click Next.
 
-* On the next page, enter "Existing Code Location" to be the directory of your IDF project. Don't specify the path to the ESP-IDF directory itself.
+* On the next page, enter "Existing Code Location" to be the directory of your IDF project. Don't specify the path to the ESP-IDF directory itself (that comes later). The directory you specify should contain a file named "Makefile" (the project Makefile).
 
 * On the same page, under "Toolchain for Indexer Settings" choose "Cross GCC". Then click Finish.
 
@@ -36,15 +45,9 @@ Project Properties
 
 * The new project will appear under Project Explorer. Right-click the project and choose Properties from the context menu.
 
-* Click on the "Environment" properties page under "C/C++ Build". Click "Add..." and enter name ``V`` and value ``1``.
+* Click on the "Environment" properties page under "C/C++ Build". Click "Add..." and enter name ``BATCH_BUILD`` and value ``1``.
 
-* Click "Add..." again, and enter name ``IDF_PATH``. The value should be the full path where ESP-IDF is installed. *Windows users: Use forward-slashes not backslashes for this path, ie C:/Users/MyUser/Development/esp-idf*.
-
-*Windows users only, follow these two additional steps:*
-
-* On the same Environment property page, edit the PATH environment variable. Delete the existing value and replace it with ``C:\msys32\usr\bin;C:\msys32\mingw32\bin;C:\msys32\opt\xtensa-esp32-elf\bin`` (If you installed msys32 to a different directory then you'll need to change these paths to match).
-
-* Click on the "C/C++ Build" top-level properties page then uncheck "Use default build command" and enter this for the custom build command: ``bash ${IDF_PATH}/tools/windows/eclipse_make.sh``.
+* Click "Add..." again, and enter name ``IDF_PATH``. The value should be the full path where ESP-IDF is installed.
 
 *All users, continue with these steps:*
 
@@ -56,7 +59,22 @@ Navigate to "C/C++ General" -> "Preprocessor Include Paths" property page:
 
 * In the list of providers, click "CDT GCC Build Output Parser" and type ``xtensa-esp32-elf-`` at the beginning of the Compiler command pattern. This means the full Compiler command pattern should be ``xtensa-esp32-elf-(g?cc)|([gc]\+\+)|(clang)``
 
-* Click OK to close the Properties dialog, and choose Project -> Build to build your project.
+.. _eclipse-build-project:
+
+Building in Eclipse
+-------------------
+
+Before your project is first built, Eclipse may show a lot of errors and warnings about undefined values. This is because some source files are automatically generated as part of the esp-idf build process. These errors and warnings will go away after you build the project.
+
+* Click OK to close the Properties dialog in Eclipse.
+
+* Outside Eclipse, open a command line prompt. Navigate to your project directory, and run ``make menuconfig`` to configure your project's esp-idf settings. This step currently has to be run outside Eclipse.
+
+*If you try to build without running a configuration step first, esp-idf will prompt for configuration on the command line - but Eclipse is not able to deal with this, so the build will hang or fail.*
+
+* Back in Eclipse, choose Project -> Build to build your project.
+
+**TIP**: If your project had already been built outside Eclipse, you may need to do a Project -> Clean before chosing Project -> Build. This is so Eclipse can see the compiler arguments for all source files. It uses these to determine the header include paths.
 
 Flash from Eclipse
 ------------------
@@ -77,7 +95,3 @@ Follow the same steps to add ``bootloader`` and ``partition_table`` targets, if
 
 .. _eclipse.org: http://www.eclipse.org/
 
-Eclipse Troubleshooting
------------------------
-
-* ``*** Make was invoked from ... However please do not run make from the sdk or a component directory; ...`` - Eclipse will detect any directory with a Makefile in it as being a possible directory to run "make" in. All component directories also contain a Makefile (the wrong one), so it is important when using Project -> Make Target to always select the top-level project directory in Project Explorer.
diff --git a/examples/bluetooth/gatt_client/main/gattc_demo.c b/examples/bluetooth/gatt_client/main/gattc_demo.c
index 4a2fa0051..290448491 100644
--- a/examples/bluetooth/gatt_client/main/gattc_demo.c
+++ b/examples/bluetooth/gatt_client/main/gattc_demo.c
@@ -295,6 +295,12 @@ static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *par
         esp_ble_gap_start_scanning(duration);
         break;
     }
+    case ESP_GAP_BLE_SCAN_START_COMPLETE_EVT:
+        //scan start complete event to indicate scan start successfully or failed
+        if (param->scan_start_cmpl.status != ESP_BT_STATUS_SUCCESS) {
+            ESP_LOGE(GATTC_TAG, "Scan start failed\n");
+        }
+        break;
     case ESP_GAP_BLE_SCAN_RESULT_EVT: {
         esp_ble_gap_cb_param_t *scan_result = (esp_ble_gap_cb_param_t *)param;
         switch (scan_result->scan_rst.search_evt) {
diff --git a/examples/bluetooth/gatt_server/main/gatts_demo.c b/examples/bluetooth/gatt_server/main/gatts_demo.c
index acbf9195a..39d33286a 100644
--- a/examples/bluetooth/gatt_server/main/gatts_demo.c
+++ b/examples/bluetooth/gatt_server/main/gatts_demo.c
@@ -151,6 +151,12 @@ static void gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param
     case ESP_GAP_BLE_SCAN_RSP_DATA_RAW_SET_COMPLETE_EVT:
         esp_ble_gap_start_advertising(&test_adv_params);
         break;
+    case ESP_GAP_BLE_ADV_START_COMPLETE_EVT:
+        //advertising start complete event to indicate advertising start successfully or failed
+        if (param->adv_start_cmpl.status != ESP_BT_STATUS_SUCCESS) {
+            ESP_LOGE(GATTS_TAG, "Advertising start failed\n");
+        }
+        break;
     default:
         break;
     }
diff --git a/examples/bluetooth/gatt_server_service_table/main/gatts_table_creat_demo.c b/examples/bluetooth/gatt_server_service_table/main/gatts_table_creat_demo.c
index 71baf1842..9bb03e7e8 100644
--- a/examples/bluetooth/gatt_server_service_table/main/gatts_table_creat_demo.c
+++ b/examples/bluetooth/gatt_server_service_table/main/gatts_table_creat_demo.c
@@ -203,6 +203,12 @@ static void gap_event_handler(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param
     case ESP_GAP_BLE_ADV_DATA_SET_COMPLETE_EVT:
         esp_ble_gap_start_advertising(&heart_rate_adv_params);
         break;
+    case ESP_GAP_BLE_ADV_START_COMPLETE_EVT:
+        //advertising start complete event to indicate advertising start successfully or failed
+        if (param->adv_start_cmpl.status != ESP_BT_STATUS_SUCCESS) {
+            ESP_LOGE(GATTS_TABLE_TAG, "Advertising start failed\n");
+        }
+        break;
     default:
         break;
     }
diff --git a/examples/protocols/sntp/main/sntp_main.c b/examples/protocols/sntp/main/sntp_main.c
index f128323dc..438505d7b 100644
--- a/examples/protocols/sntp/main/sntp_main.c
+++ b/examples/protocols/sntp/main/sntp_main.c
@@ -110,6 +110,8 @@ static void obtain_time(void)
         time(&now);
         localtime_r(&now, &timeinfo);
     }
+
+    ESP_ERROR_CHECK( esp_wifi_stop() );
 }
 
 static void initialize_sntp(void)
diff --git a/make/build_examples.sh b/make/build_examples.sh
index e85ec26a7..ee429309e 100755
--- a/make/build_examples.sh
+++ b/make/build_examples.sh
@@ -9,6 +9,9 @@
 #
 [ -z ${IDF_PATH} ] && echo "IDF_PATH is not set" && exit 1
 
+export BATCH_BUILD=1
+export V=0 # only build verbose if there's an error
+
 EXAMPLE_NUM=1
 RESULT=0
 FAILED_EXAMPLES=""
@@ -36,7 +39,7 @@ for category in ${IDF_PATH}/examples/*; do
             set -e
             make clean defconfig
             make $* all 2>&1 | tee $BUILDLOG
-        ) || { RESULT=$?; FAILED_EXAMPLES+=" ${example}"; make V=1; } # only build verbose if there's an error
+        ) || { RESULT=$?; FAILED_EXAMPLES+=" ${example}"; make V=1; } # verbose output for errors
         popd
         EXAMPLE_NUM=$(( $EXAMPLE_NUM + 1 ))
 
diff --git a/make/common.mk b/make/common.mk
index 605b8ab86..41a87b3a6 100644
--- a/make/common.mk
+++ b/make/common.mk
@@ -7,9 +7,14 @@
 # (Note that we only rebuild this makefile automatically for some
 # targets, see project_config.mk for details.)
 SDKCONFIG_MAKEFILE ?= $(abspath $(BUILD_DIR_BASE)/include/config/auto.conf)
--include $(SDKCONFIG_MAKEFILE)
+include $(SDKCONFIG_MAKEFILE)
 export SDKCONFIG_MAKEFILE  # sub-makes (like bootloader) will reuse this path
 
+# BATCH_BUILD flag disables interactive terminal features, defaults to verbose build
+ifdef BATCH_BUILD
+V ?= 1
+endif
+
 #Handling of V=1/VERBOSE=1 flag
 #
 # if V=1, $(summary) does nothing and $(details) will echo extra details
diff --git a/make/project.mk b/make/project.mk
index bebb1fc7d..04015a8a8 100644
--- a/make/project.mk
+++ b/make/project.mk
@@ -49,14 +49,23 @@ endif
 # make IDF_PATH a "real" absolute path
 # * works around the case where a shell character is embedded in the environment variable value.
 # * changes Windows-style C:/blah/ paths to MSYS/Cygwin style /c/blah
-export IDF_PATH:=$(realpath $(wildcard $(IDF_PATH)))
+ifeq ("$(OS)","Windows_NT")
+# On Windows MSYS2, make wildcard function returns empty string for paths of form /xyz
+# where /xyz is a directory inside the MSYS root - so we don't use it.
+SANITISED_IDF_PATH:=$(realpath $(IDF_PATH))
+else
+SANITISED_IDF_PATH:=$(realpath $(wildcard $(IDF_PATH)))
+endif
+
+export IDF_PATH := $(SANITISED_IDF_PATH)
 
 ifndef IDF_PATH
 $(error IDF_PATH variable is not set to a valid directory.)
 endif
 
-ifneq ("$(IDF_PATH)","$(realpath $(wildcard $(IDF_PATH)))")
-# due to the way make manages variables, this is hard to account for
+ifneq ("$(IDF_PATH)","$(SANITISED_IDF_PATH)")
+# implies IDF_PATH was overriden on make command line.
+# Due to the way make manages variables, this is hard to account for
 #
 # if you see this error, do the shell expansion in the shell ie
 # make IDF_PATH=~/blah not make IDF_PATH="~/blah"
@@ -370,12 +379,7 @@ $(BUILD_DIR_BASE)/$(2)/lib$(2).a: $(2)-build
 # If any component_project_vars.mk file is out of date, the make
 # process will call this target to rebuild it and then restart.
 #
-# Note: $(SDKCONFIG) is a normal prereq as we need to rebuild these
-# files whenever the config changes. $(SDKCONFIG_MAKEFILE) is an
-# order-only prereq because if it hasn't been rebuilt, we need to
-# build it first - but including it as a normal prereq can lead to
-# infinite restarts as the conf process will keep updating it.
-$(BUILD_DIR_BASE)/$(2)/component_project_vars.mk: $(1)/component.mk $(COMMON_MAKEFILES) $(SDKCONFIG) | $(BUILD_DIR_BASE)/$(2) $(SDKCONFIG_MAKEFILE)
+$(BUILD_DIR_BASE)/$(2)/component_project_vars.mk: $(1)/component.mk $(COMMON_MAKEFILES) $(SDKCONFIG_MAKEFILE) | $(BUILD_DIR_BASE)/$(2)
 	$(call ComponentMake,$(1),$(2)) component_project_vars.mk
 endef
 
diff --git a/make/project_config.mk b/make/project_config.mk
index 011aa1ff0..c0369f95f 100644
--- a/make/project_config.mk
+++ b/make/project_config.mk
@@ -20,59 +20,77 @@ $(KCONFIG_TOOL_DIR)/mconf $(KCONFIG_TOOL_DIR)/conf:
 	MAKEFLAGS=$(ORIGINAL_MAKEFLAGS) CC=$(HOSTCC) LD=$(HOSTLD) \
 	$(MAKE) -C $(KCONFIG_TOOL_DIR)
 
-# use a wrapper environment for where we run Kconfig tools
-KCONFIG_TOOL_ENV=KCONFIG_AUTOHEADER=$(abspath $(BUILD_DIR_BASE)/include/sdkconfig.h) \
-	COMPONENT_KCONFIGS="$(COMPONENT_KCONFIGS)" KCONFIG_CONFIG=$(SDKCONFIG) \
-	COMPONENT_KCONFIGS_PROJBUILD="$(COMPONENT_KCONFIGS_PROJBUILD)"
-
-menuconfig: $(KCONFIG_TOOL_DIR)/mconf $(IDF_PATH)/Kconfig $(call prereq_if_explicit,defconfig)
-	$(summary) MENUCONFIG
-	$(KCONFIG_TOOL_ENV) $(KCONFIG_TOOL_DIR)/mconf $(IDF_PATH)/Kconfig
-
 ifeq ("$(wildcard $(SDKCONFIG))","")
-ifeq ("$(call prereq_if_explicit,defconfig)","")
-# if not configuration is present and defconfig is not a target, run defconfig then menuconfig
-$(SDKCONFIG): defconfig menuconfig
+ifeq ("$(filter defconfig, $(MAKECMDGOALS))","")
+# if no configuration file is present and defconfig is not a named
+# target, run defconfig then menuconfig to get the initial config
+$(SDKCONFIG): menuconfig
+menuconfig: defconfig
 else
-# otherwise, just defconfig
+# otherwise, just run defconfig
 $(SDKCONFIG): defconfig
 endif
 endif
 
+# macro for the commands to run kconfig tools conf or mconf.
+# $1 is the name (& args) of the conf tool to run
+define RunConf
+	mkdir -p $(BUILD_DIR_BASE)/include/config
+	cd $(BUILD_DIR_BASE); KCONFIG_AUTOHEADER=$(abspath $(BUILD_DIR_BASE)/include/sdkconfig.h) \
+	COMPONENT_KCONFIGS="$(COMPONENT_KCONFIGS)" KCONFIG_CONFIG=$(SDKCONFIG) \
+	COMPONENT_KCONFIGS_PROJBUILD="$(COMPONENT_KCONFIGS_PROJBUILD)" \
+	$(KCONFIG_TOOL_DIR)/$1 $(IDF_PATH)/Kconfig
+endef
+
+ifeq ("$(MAKE_RESTARTS)","")
+# menuconfig, defconfig and "GENCONFIG" configuration generation only
+# ever run on the first make pass, subsequent passes don't run these
+# (make often wants to re-run them as the conf tool can regenerate the
+# sdkconfig input file as an output file, but this is not what the
+# user wants - a single config pass is enough to produce all output
+# files.)
+#
+# To prevent problems missing genconfig, ensure none of these targets
+# depend on any prerequisite that may cause a make restart as part of
+# the prerequisite's own recipe.
+
+menuconfig: $(KCONFIG_TOOL_DIR)/mconf
+	$(summary) MENUCONFIG
+ifdef BATCH_BUILD
+	@echo "Can't run interactive configuration inside non-interactive build process."
+	@echo ""
+	@echo "Open a command line terminal and run 'make menuconfig' from there."
+	@echo "See esp-idf documentation for more details."
+	@exit 1
+else
+	$(call RunConf,mconf)
+endif
+
 # defconfig creates a default config, based on SDKCONFIG_DEFAULTS if present
-defconfig: $(KCONFIG_TOOL_DIR)/mconf $(IDF_PATH)/Kconfig $(BUILD_DIR_BASE)
+defconfig: $(KCONFIG_TOOL_DIR)/conf
 	$(summary) DEFCONFIG
 ifneq ("$(wildcard $(SDKCONFIG_DEFAULTS))","")
 	cat $(SDKCONFIG_DEFAULTS) >> $(SDKCONFIG)  # append defaults to sdkconfig, will override existing values
 endif
-	mkdir -p $(BUILD_DIR_BASE)/include/config
-	$(KCONFIG_TOOL_ENV) $(KCONFIG_TOOL_DIR)/conf --olddefconfig $(IDF_PATH)/Kconfig
+	$(call RunConf,conf --olddefconfig)
 
-# Work out of whether we have to build the Kconfig makefile
-# (auto.conf), or if we're in a situation where we don't need it
-NON_CONFIG_TARGETS := clean %-clean help menuconfig defconfig
-AUTO_CONF_REGEN_TARGET := $(SDKCONFIG_MAKEFILE)
-
-# disable AUTO_CONF_REGEN_TARGET if all targets are non-config targets
-# (and not building default target)
-ifneq ("$(MAKECMDGOALS)","")
-ifeq ($(filter $(NON_CONFIG_TARGETS), $(MAKECMDGOALS)),$(MAKECMDGOALS))
-AUTO_CONF_REGEN_TARGET :=
-# dummy target
-$(SDKCONFIG_MAKEFILE):
-endif
-endif
-
-$(AUTO_CONF_REGEN_TARGET) $(BUILD_DIR_BASE)/include/sdkconfig.h: $(SDKCONFIG) $(KCONFIG_TOOL_DIR)/conf $(COMPONENT_KCONFIGS) $(COMPONENT_KCONFIGS_PROJBUILD)
+# if neither defconfig or menuconfig are requested, use the GENCONFIG rule to
+# ensure generated config files are up to date
+$(SDKCONFIG_MAKEFILE) $(BUILD_DIR_BASE)/include/sdkconfig.h: $(KCONFIG_TOOL_DIR)/conf $(SDKCONFIG) $(COMPONENT_KCONFIGS) $(COMPONENT_KCONFIGS_PROJBUILD) | $(call prereq_if_explicit,defconfig) $(call prereq_if_explicit,menuconfig)
 	$(summary) GENCONFIG
-	mkdir -p $(BUILD_DIR_BASE)/include/config
-	cd $(BUILD_DIR_BASE); $(KCONFIG_TOOL_ENV) $(KCONFIG_TOOL_DIR)/conf --silentoldconfig $(IDF_PATH)/Kconfig
-	touch $(AUTO_CONF_REGEN_TARGET) $(BUILD_DIR_BASE)/include/sdkconfig.h
-# touch to ensure both output files are newer - as 'conf' can also update sdkconfig (a dependency). Without this,
-# sometimes you can get an infinite make loop on Windows where sdkconfig always gets regenerated newer
-# than the target(!)
+ifdef BATCH_BUILD  # can't prompt for new config values like on terminal
+	$(call RunConf,conf --olddefconfig)
+endif
+	$(call RunConf,conf --silentoldconfig)
+	touch $(SDKCONFIG_MAKEFILE) $(BUILD_DIR_BASE)/include/sdkconfig.h  # ensure newer than sdkconfig
 
-.PHONY: config-clean
+else  # "$(MAKE_RESTARTS)" != ""
+# on subsequent make passes, skip config generation entirely
+defconfig:
+menuconfig:
+endif
+
+.PHONY: config-clean defconfig menuconfig
 config-clean:
 	$(summary RM CONFIG)
 	$(MAKE) -C $(KCONFIG_TOOL_DIR) clean
diff --git a/tools/kconfig/.gitignore b/tools/kconfig/.gitignore
index be603c4fe..977c274ce 100644
--- a/tools/kconfig/.gitignore
+++ b/tools/kconfig/.gitignore
@@ -20,3 +20,11 @@ nconf
 qconf
 gconf
 kxgettext
+
+# configuration programs, Windows
+conf.exe
+mconf.exe
+nconf.exe
+qconf.exe
+gconf.exe
+kxgettext.exe
diff --git a/tools/windows/eclipse_make.py b/tools/windows/eclipse_make.py
new file mode 100644
index 000000000..e65cfc9cc
--- /dev/null
+++ b/tools/windows/eclipse_make.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+#
+# Wrapper to run make and preprocess any paths in the output from MSYS/Cygwin paths
+# to Windows paths, for Eclipse
+from __future__ import print_function, division
+import sys, subprocess, os.path, re
+
+UNIX_PATH_RE = re.compile(r'(/[^ \'"]+)+')
+
+paths = {}
+def check_path(path):
+    try:
+        return paths[path]
+    except KeyError:
+        pass
+    paths[path] = path  # cache as failed, replace with success if it works
+    try:
+        winpath = subprocess.check_output(["cygpath", "-w", path]).strip()
+    except subprocess.CalledProcessError:
+        return path  # something went wrong running cygpath, assume this is not a path!
+    if not os.path.exists(winpath):
+        return path  # not actually a valid path
+    winpath = winpath.replace("\\", "/")  # make consistent with forward-slashes used elsewhere
+    paths[path] = winpath
+    return winpath
+
+def main():
+    print("Running make in '%s'" % check_path(os.getcwd()))
+    make = subprocess.Popen(["make"] + sys.argv[1:] + ["BATCH_BUILD=1"], stdout=subprocess.PIPE)
+    for line in iter(make.stdout.readline, ''):
+         line = re.sub(UNIX_PATH_RE, lambda m: check_path(m.group(0)), line)
+         print(line.rstrip())
+    sys.exit(make.wait())
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/windows/eclipse_make.sh b/tools/windows/eclipse_make.sh
index 200d798ff..769bca269 100755
--- a/tools/windows/eclipse_make.sh
+++ b/tools/windows/eclipse_make.sh
@@ -1,9 +1,4 @@
 #!/bin/bash
-# A wrapper for make on Windows with Eclipse
-#
-# Eclipse's output parser expects to see output of the form C:/dir/dir/file but our Make
-# process uses MinGW paths of the form /c/dir/dir/file. So parse these out...
-#
-# (regexp deliberate only matches after a space character to try and avoid false-positives.)
-echo "Running make in $(pwd)"
-make $@ V=1 | sed -E "s@ /([a-z])/(.+)/@ \1:/\2/@g" | sed -E "s@-I/([a-z])/(.+)/@-I\1:/\2/@g" | sed -E "s@-L/([a-z])/(.+)/@-L\1:/\2/@g"
+echo "eclipse_make.sh has been replaced with eclipse_make.py. Check the Windows Eclipse docs for the new command."
+echo "This shell script will continue to work until the next major release."
+python ${IDF_PATH}/tools/windows/eclipse_make.py $@