diff --git a/components/bt/bluedroid/btc/profile/esp/blufi/blufi_prf.c b/components/bt/bluedroid/btc/profile/esp/blufi/blufi_prf.c
index 7379192577..800f8d8d75 100644
--- a/components/bt/bluedroid/btc/profile/esp/blufi/blufi_prf.c
+++ b/components/bt/bluedroid/btc/profile/esp/blufi/blufi_prf.c
@@ -345,7 +345,7 @@ static void btc_blufi_send_notify(uint8_t *pkt, int pkt_len)
 static void btc_blufi_recv_handler(uint8_t *data, int len)
 {
     struct blufi_hdr *hdr = (struct blufi_hdr *)data;
-    uint16_t checksum;
+    uint16_t checksum, checksum_pkt;
     int ret;
 
     if (hdr->seq != blufi_env.recv_seq) {
@@ -369,8 +369,9 @@ static void btc_blufi_recv_handler(uint8_t *data, int len)
     if (BLUFI_FC_IS_CHECK(hdr->fc)
             && (blufi_env.cbs && blufi_env.cbs->checksum_func)) {
         checksum = blufi_env.cbs->checksum_func(hdr->seq, &hdr->seq, hdr->data_len + 2);
-        if (memcmp(&checksum, &hdr->data[hdr->data_len], 2) != 0) {
-            LOG_ERROR("%s checksum error %04x, pkt %04x\n", __func__, checksum, *(uint16_t *)&hdr->data[hdr->data_len]);
+        checksum_pkt = hdr->data[hdr->data_len] | (((uint16_t) hdr->data[hdr->data_len + 1]) << 8);
+        if (checksum != checksum_pkt) {
+            LOG_ERROR("%s checksum error %04x, pkt %04x\n", __func__, checksum, checksum_pkt);
             return;
         }
     }
@@ -381,7 +382,7 @@ static void btc_blufi_recv_handler(uint8_t *data, int len)
 
     if (BLUFI_FC_IS_FRAG(hdr->fc)) {
         if (blufi_env.offset == 0) {
-            blufi_env.total_len = *(uint16_t *)(hdr->data);
+            blufi_env.total_len = hdr->data[0] | (((uint16_t) hdr->data[1]) << 8);
             blufi_env.aggr_buf = GKI_getbuf(blufi_env.total_len);
             if (blufi_env.aggr_buf == NULL) {
                 LOG_ERROR("%s no mem, len %d\n", __func__, blufi_env.total_len);
@@ -420,7 +421,8 @@ void btc_blufi_send_encap(uint8_t type, uint8_t *data, int total_data_len)
             }
             hdr->fc = 0x0;
             hdr->data_len = blufi_env.frag_size + 2;
-            *(uint16_t *)hdr->data = remain_len;
+            hdr->data[0] = remain_len & 0xff;
+            hdr->data[1] = (remain_len >> 8) & 0xff;
             memcpy(hdr->data + 2, &data[total_data_len - remain_len], blufi_env.frag_size); //copy first, easy for check sum
             hdr->fc |= BLUFI_FC_FRAG;
         } else {
diff --git a/components/bt/bluedroid/stack/btu/btu_task.c b/components/bt/bluedroid/stack/btu/btu_task.c
index 4c640fad7c..feaa50faf8 100644
--- a/components/bt/bluedroid/stack/btu/btu_task.c
+++ b/components/bt/bluedroid/stack/btu/btu_task.c
@@ -223,8 +223,11 @@ static void btu_hci_msg_process(BT_HDR *p_msg)
     /* Determine the input message type. */
     switch (p_msg->event & BT_EVT_MASK) {
     case BTU_POST_TO_TASK_NO_GOOD_HORRIBLE_HACK: // TODO(zachoverflow): remove this
-        ((post_to_task_hack_t *)(&p_msg->data[0]))->callback(p_msg);
+      {
+        post_to_task_hack_t *ph = (post_to_task_hack_t *) &p_msg->data[0];
+        ph->callback(p_msg);
         break;
+      }
     case BT_EVT_TO_BTU_HCI_ACL:
         /* All Acl Data goes to L2CAP */
         l2c_rcv_acl_data (p_msg);
diff --git a/components/driver/ledc.c b/components/driver/ledc.c
index e1a124b5ec..9cea7b5ec7 100644
--- a/components/driver/ledc.c
+++ b/components/driver/ledc.c
@@ -541,6 +541,7 @@ esp_err_t ledc_set_fade_with_step(ledc_mode_t speed_mode, ledc_channel_t channel
     int duty_cur = LEDC.channel_group[speed_mode].channel[channel].duty_rd.duty_read >> LEDC_DUTY_DECIMAL_BIT_NUM;
     int duty_delta = target_duty > duty_cur ? target_duty - duty_cur : duty_cur - target_duty;
     if (duty_delta == 0) {
+        portEXIT_CRITICAL(&ledc_spinlock);
         return ESP_OK;
     }
     s_ledc_fade_rec[speed_mode][channel]->speed_mode = speed_mode;
diff --git a/components/driver/spi_master.c b/components/driver/spi_master.c
index 23aaf5df5e..8951371fdc 100644
--- a/components/driver/spi_master.c
+++ b/components/driver/spi_master.c
@@ -698,8 +698,8 @@ esp_err_t spi_device_queue_trans(spi_device_handle_t handle, spi_transaction_t *
 {
     BaseType_t r;
     SPI_CHECK(handle!=NULL, "invalid dev handle", ESP_ERR_INVALID_ARG);
-    SPI_CHECK((trans_desc->flags & SPI_TRANS_USE_RXDATA)==0 ||trans_desc->length <= 32, "rxdata transfer > 32bytes", ESP_ERR_INVALID_ARG);
-    SPI_CHECK((trans_desc->flags & SPI_TRANS_USE_TXDATA)==0 ||trans_desc->length <= 32, "txdata transfer > 32bytes", ESP_ERR_INVALID_ARG);
+    SPI_CHECK((trans_desc->flags & SPI_TRANS_USE_RXDATA)==0 ||trans_desc->rxlength <= 32, "rxdata transfer > 32 bits", ESP_ERR_INVALID_ARG);
+    SPI_CHECK((trans_desc->flags & SPI_TRANS_USE_TXDATA)==0 ||trans_desc->length <= 32, "txdata transfer > 32 bits", ESP_ERR_INVALID_ARG);
     SPI_CHECK(!((trans_desc->flags & (SPI_TRANS_MODE_DIO|SPI_TRANS_MODE_QIO)) && (handle->cfg.flags & SPI_DEVICE_3WIRE)), "incompatible iface params", ESP_ERR_INVALID_ARG);
     SPI_CHECK(!((trans_desc->flags & (SPI_TRANS_MODE_DIO|SPI_TRANS_MODE_QIO)) && (!(handle->cfg.flags & SPI_DEVICE_HALFDUPLEX))), "incompatible iface params", ESP_ERR_INVALID_ARG);
     r=xQueueSend(handle->trans_queue, (void*)&trans_desc, ticks_to_wait);
diff --git a/examples/system/ota/README.md b/examples/system/ota/README.md
index 886dbf5fbb..2b0e0202b0 100644
--- a/examples/system/ota/README.md
+++ b/examples/system/ota/README.md
@@ -16,7 +16,7 @@ In this example, the ESP32 has 3 images in flash: factory, OTA_0, OTA_1. Each of
 Flashing the example over serial with "make flash" updates the factory app image. On first boot, the bootloader loads this factory app image which then performs an OTA update (triggered in the example code). The update downloads a new image from an http server and saves it into the OTA_0 partition. At this point the example code updates the ota_data partition to indicate the new app partition, and resets. The bootloader reads ota_data, determines the new OTA image has been selected, and runs it.
 
 
-# Worflow
+# Workflow
 
 The OTA_workflow.png diagram demonstrates the overall workflow:
 
diff --git a/make/project.mk b/make/project.mk
index fd85ef4e55..1c868ad307 100644
--- a/make/project.mk
+++ b/make/project.mk
@@ -189,9 +189,9 @@ endif
 IDF_VER := $(shell cd ${IDF_PATH} && git describe --always --tags --dirty)
 
 # Set default LDFLAGS
-
+SRCDIRS_COMPONENT_NAMES := $(sort $(foreach comp,$(SRCDIRS),$(lastword $(subst /, ,$(comp)))))
 LDFLAGS ?= -nostdlib \
-	$(addprefix -L$(BUILD_DIR_BASE)/,$(COMPONENTS) $(TEST_COMPONENT_NAMES) $(SRCDIRS) ) \
+	$(addprefix -L$(BUILD_DIR_BASE)/,$(COMPONENTS) $(TEST_COMPONENT_NAMES) $(SRCDIRS_COMPONENT_NAMES) ) \
 	-u call_user_start_cpu0	\
 	$(EXTRA_LDFLAGS) \
 	-Wl,--gc-sections	\