diff --git a/features/FEATURE_BLE/ble/deprecate.h b/features/FEATURE_BLE/ble/deprecate.h
index 47fd3bb2d5..f0b7d38cb8 100644
--- a/features/FEATURE_BLE/ble/deprecate.h
+++ b/features/FEATURE_BLE/ble/deprecate.h
@@ -23,4 +23,4 @@
 	#define __deprecated_message(msg)
 #endif
 
-#endif
\ No newline at end of file
+#endif
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/common/ble_conn_state.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/common/ble_conn_state.c
index 739cf1f638..a5f5461595 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/common/ble_conn_state.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/common/ble_conn_state.c
@@ -169,7 +169,7 @@ static void record_purge_disconnected()
                                    m_bcs.valid_conn_handles,
                                  (~m_bcs.flags.connected_flags) & (m_bcs.flags.valid_flags));
 
-    for (int i = 0; i < disconnected_list.len; i++)
+    for (uint32_t i = 0; i < disconnected_list.len; i++)
     {
         record_invalidate(disconnected_list.flag_keys[i]);
     }
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/peer_database.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/peer_database.c
index a34fc78fb3..8a790c02dd 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/peer_database.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/peer_database.c
@@ -172,7 +172,7 @@ static pdb_buffer_record_t * write_buffer_record_find_unused(void)
  */
 static void write_buffer_record_release(pdb_buffer_record_t * p_write_buffer_record)
 {
-    for (int i = 0; i < p_write_buffer_record->n_bufs; i++)
+    for (uint32_t i = 0; i < p_write_buffer_record->n_bufs; i++)
     {
         pm_buffer_release(&m_pdb.write_buffer, p_write_buffer_record->buffer_block_id + i);
     }
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/pm_buffer.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/pm_buffer.c
index 87379e3ac0..4299793732 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/pm_buffer.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/ble/peer_manager/pm_buffer.c
@@ -93,7 +93,7 @@ uint8_t pm_buffer_block_acquire(pm_buffer_t * p_buffer, uint32_t n_blocks)
             {
                 first_locked_mutex = i;
             }
-            if ((i - first_locked_mutex + 1) == n_blocks)
+            if ((i - first_locked_mutex + 1) >= 0 && ((uint32_t)(i - first_locked_mutex + 1)) == n_blocks)
             {
                 return first_locked_mutex;
             }
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/drivers_nrf/delay/nrf_delay.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/drivers_nrf/delay/nrf_delay.h
index 79ba8872fb..85e2c3c8ba 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/drivers_nrf/delay/nrf_delay.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/drivers_nrf/delay/nrf_delay.h
@@ -191,8 +191,8 @@ __STATIC_INLINE void nrf_delay_us(uint32_t volatile number_of_us)
 
 #elif defined ( __GNUC__ )
 
-static void __INLINE nrf_delay_us(uint32_t volatile number_of_us) __attribute__((always_inline));
-static void __INLINE nrf_delay_us(uint32_t volatile number_of_us)
+static __INLINE void nrf_delay_us(uint32_t volatile number_of_us) __attribute__((always_inline));
+static __INLINE void nrf_delay_us(uint32_t volatile number_of_us)
 {
 register uint32_t delay __ASM ("r0") = number_of_us;
 __ASM volatile (
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds.c
index 6de311a34b..edcefd3010 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds.c
@@ -40,6 +40,10 @@
 #include "nrf_error.h"
 #include "app_util.h"
 
+static void fs_callback(uint8_t             op_code,
+                        uint32_t            result,
+                        uint32_t    const * p_data,
+                        fs_length_t         length_words);
 
 /** Our fstorage configuration.
  *  The other fields will be assigned automatically during compilation. */
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds_types_internal.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds_types_internal.h
index a97a6af196..9429285333 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds_types_internal.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fds/fds_types_internal.h
@@ -68,7 +68,7 @@
 #define FDS_CMD_QUEUE_SIZE_GC       (1)
 
 
-static uint8_t m_nested_critical;
+//static uint8_t m_nested_critical;
 
 /** Macros to enable and disable application interrupts. */
 #define CRITICAL_SECTION_ENTER()    //sd_nvic_critical_region_enter(&m_nested_critical)
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.c
index d75df2ecb1..8cc8cc1af0 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.c
@@ -559,7 +559,7 @@ void fs_debug_print()
     printf("Num items: 0x%08lx\r\n",        (unsigned long)FS_SECTION_VARS_COUNT);
     printf("===== ITEMS %lu =====\r\n",     (unsigned long)FS_SECTION_VARS_COUNT);
 
-    for(int i = 0; i < FS_SECTION_VARS_COUNT; i++)
+    for(uint32_t i = 0; i < FS_SECTION_VARS_COUNT; i++)
     {
         fs_config_t* config = FS_SECTION_VARS_GET(i);
         printf( "Address: 0x%08lx, CB: 0x%08lx\r\n",
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.h
index cf19e2e25b..6f364ca27c 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/fstorage/fstorage.h
@@ -74,23 +74,6 @@ typedef void (*fs_cb_t)(uint8_t             op_code,
                         fs_length_t         length_words);
 
 
-/**@brief Function prototype for a callback handler.
- *
- * @details This function is expected to be implemented by the module that 
- *          registers for fstorage usage. Its usage is described
- *          in the function pointer type fs_cb_t.
- *
- * @param[in]   op_code         Flash operation code.
- * @param[in]   result          Result of the flash operation.
- * @param[in]   p_data          Pointer to the resulting data (or NULL if not in use).
- * @param[in]   length_words    Length of data in words.
- */
-static void fs_callback(uint8_t             op_code,
-                        uint32_t            result,
-                        uint32_t    const * p_data,
-                        fs_length_t         length_words);
-
-
 /**@brief Flash storage config variable.
  *
  * @details     The fstorage module will update the start_addr and end_address according to 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/app_util_platform.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/app_util_platform.h
index de07685736..dd5c984357 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/app_util_platform.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/app_util_platform.h
@@ -68,8 +68,6 @@ typedef enum
 #define EXTERNAL_INT_VECTOR_OFFSET 16
 /**@endcond */
 
-#define PACKED(TYPE) __packed TYPE
-
 void critical_region_enter (void);
 void critical_region_exit (void);
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/sdk_mapped_flags.c b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/sdk_mapped_flags.c
index 93a17d7e9f..78d3929ea8 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/sdk_mapped_flags.c
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/libraries/util/sdk_mapped_flags.c
@@ -111,7 +111,7 @@ void sdk_mapped_flags_bulk_update_by_key(uint16_t           * p_keys,
         {
             if (p_keys[i] == key)
             {
-                for (int j = 0; j < n_flag_collections; j++)
+                for (uint32_t j = 0; j < n_flag_collections; j++)
                 {
                     if (value)
                     {
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/softdevice/s130/headers/nrf_svc.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/softdevice/s130/headers/nrf_svc.h
index e7b8f59471..9311be90cc 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/softdevice/s130/headers/nrf_svc.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/sdk/source/softdevice/s130/headers/nrf_svc.h
@@ -42,11 +42,11 @@
 #define SVCALL(number, return_type, signature) return_type __svc(number) signature
 #elif defined (__GNUC__)
 #define SVCALL(number, return_type, signature) \
-  _Pragma("GCC diagnostic ignored \"-Wunused-function\"") \
-  _Pragma("GCC diagnostic ignored \"-Wunused-parameter\"") \
   _Pragma("GCC diagnostic push") \
   _Pragma("GCC diagnostic ignored \"-Wreturn-type\"") \
-  __attribute__((naked)) static return_type signature \
+  __attribute__((naked))                                \
+  __attribute__((unused))                               \
+  static return_type signature                          \
   { \
     __asm( \
         "svc %0\n" \
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle.cpp
index cee1cfca9e..0bb0c400fe 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle.cpp
@@ -234,7 +234,7 @@ static void btle_handler(ble_evt_t *p_ble_evt)
 /*! @brief      Callback when an error occurs inside the SoftDevice */
 void assert_nrf_callback(uint16_t line_num, const uint8_t *p_file_name)
 {
-    ASSERT(false, (void) 0);
+    ASSERT_TRUE(false, (void) 0);
 }
 
 /*!
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle_discovery.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle_discovery.cpp
index 4d5eea004d..d6f815d64e 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle_discovery.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/btle_discovery.cpp
@@ -23,7 +23,6 @@
 void bleGattcEventHandler(const ble_evt_t *p_ble_evt)
 {
     nRF5xn                &ble         = nRF5xn::Instance(BLE::DEFAULT_INSTANCE);
-    nRF5xGap              &gap         = (nRF5xGap &) ble.getGap();
     nRF5xGattClient       &gattClient  = (nRF5xGattClient &) ble.getGattClient();
     nRF5xServiceDiscovery &sdSingleton = gattClient.discovery();
     nRF5xCharacteristicDescriptorDiscoverer &characteristicDescriptorDiscoverer =
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/custom/custom_helper.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/custom/custom_helper.cpp
index 60ff8544c5..b7fbb61d77 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/custom/custom_helper.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/btle/custom/custom_helper.cpp
@@ -135,7 +135,7 @@ ble_uuid_t custom_convert_to_nordic_uuid(const UUID &uuid)
     #define CFG_CUSTOM_UUID_BASE  "\x6E\x40\x00\x00\xB5\xA3\xF3\x93\xE0\xA9\xE5\x0E\x24\xDC\xCA\x9E"
 
     uint8_t uuid_type = custom_add_uuid_base(CFG_CUSTOM_UUID_BASE);
-    ASSERT(uuid_type > 0, ERROR_NOT_FOUND);
+    ASSERT_TRUE(uuid_type > 0, ERROR_NOT_FOUND);
 
     // We can now safely add the primary service and any characteristics
     // for our custom service ...
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/common/assertion.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/common/assertion.h
index c0bd8c0d66..71bacb3e81 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/common/assertion.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/common/assertion.h
@@ -125,7 +125,6 @@ static inline void debugger_breakpoint(void)
 //--------------------------------------------------------------------+
 // Logical Assert
 //--------------------------------------------------------------------+
-#define ASSERT(...)                      ASSERT_TRUE(__VA_ARGS__)
 #define ASSERT_TRUE(condition  , error)  ASSERT_DEFINE( , (condition), error, "%s", "evaluated to false")
 #define ASSERT_FALSE(condition , error)  ASSERT_DEFINE( ,!(condition), error, "%s", "evaluated to true")
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.cpp
index 629f471c9f..77cb11b91d 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.cpp
@@ -96,7 +96,7 @@ ble_error_t nRF5xGap::setAdvertisingData(const GapAdvertisingData &advData, cons
     //}
 
     /* Send advertising data! */
-    ASSERT(ERROR_NONE ==
+    ASSERT_TRUE(ERROR_NONE ==
            sd_ble_gap_adv_data_set(advData.getPayload(),
                                    advData.getPayloadLen(),
                                    scanResponse.getPayload(),
@@ -105,7 +105,7 @@ ble_error_t nRF5xGap::setAdvertisingData(const GapAdvertisingData &advData, cons
 
     /* Make sure the GAP Service appearance value is aligned with the
      *appearance from GapAdvertisingData */
-    ASSERT(ERROR_NONE == sd_ble_gap_appearance_set(advData.getAppearance()),
+    ASSERT_TRUE(ERROR_NONE == sd_ble_gap_appearance_set(advData.getAppearance()),
            BLE_ERROR_PARAM_OUT_OF_RANGE);
 
     /* ToDo: Perform some checks on the payload, for example the Scan Response can't */
@@ -196,7 +196,7 @@ ble_error_t nRF5xGap::startAdvertising(const GapAdvertisingParams &params)
     adv_para.interval    = params.getIntervalInADVUnits(); // advertising interval (in units of 0.625 ms)
     adv_para.timeout     = params.getTimeout();
 
-    ASSERT(ERROR_NONE == sd_ble_gap_adv_start(&adv_para), BLE_ERROR_PARAM_OUT_OF_RANGE);
+    ASSERT_TRUE(ERROR_NONE == sd_ble_gap_adv_start(&adv_para), BLE_ERROR_PARAM_OUT_OF_RANGE);
 
     return BLE_ERROR_NONE;
 }
@@ -267,7 +267,7 @@ ble_error_t nRF5xGap::stopScan(void) {
 ble_error_t nRF5xGap::stopAdvertising(void)
 {
     /* Stop Advertising */
-    ASSERT(ERROR_NONE == sd_ble_gap_adv_stop(), BLE_ERROR_PARAM_OUT_OF_RANGE);
+    ASSERT_TRUE(ERROR_NONE == sd_ble_gap_adv_stop(), BLE_ERROR_PARAM_OUT_OF_RANGE);
 
     state.advertising = 0;
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.h
index 25c507c19a..90a2e2a383 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGap.h
@@ -220,7 +220,7 @@ private:
      */
     void processRadioNotificationEvent(bool param) {
         radioNotificationCallbackParam = param;
-        radioNotificationTimeout.attach_us(this, &nRF5xGap::postRadioNotificationCallback, 0);
+        radioNotificationTimeout.attach_us(mbed::callback(this, &nRF5xGap::postRadioNotificationCallback), 0);
     }
     friend void radioNotificationStaticCallback(bool param); /* allow invocations of processRadioNotificationEvent() */
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGattServer.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGattServer.cpp
index db0647583a..4c5365f1b7 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGattServer.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/source/nRF5xGattServer.cpp
@@ -52,7 +52,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
     nordicUUID = custom_convert_to_nordic_uuid(service.getUUID());
 
     uint16_t serviceHandle;
-    ASSERT( ERROR_NONE ==
+    ASSERT_TRUE( ERROR_NONE ==
             sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY,
                                      &nordicUUID,
                                      &serviceHandle),
@@ -88,7 +88,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
             }
         }
 
-        ASSERT ( ERROR_NONE ==
+        ASSERT_TRUE ( ERROR_NONE ==
                  custom_add_in_characteristic(BLE_GATT_HANDLE_INVALID,
                                               &nordicUUID,
                                               p_char->getProperties(),
@@ -123,7 +123,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
 
             nordicUUID = custom_convert_to_nordic_uuid(p_desc->getUUID());
 
-            ASSERT(ERROR_NONE ==
+            ASSERT_TRUE(ERROR_NONE ==
                    custom_add_in_descriptor(BLE_GATT_HANDLE_INVALID,
                                             &nordicUUID,
                                             p_desc->getValuePtr(),
@@ -177,7 +177,7 @@ ble_error_t nRF5xGattServer::read(Gap::Handle_t connectionHandle, GattAttribute:
         .p_value = buffer,
     };
 
-    ASSERT( ERROR_NONE ==
+    ASSERT_TRUE( ERROR_NONE ==
             sd_ble_gatts_value_get(connectionHandle, attributeHandle, &value),
             BLE_ERROR_PARAM_OUT_OF_RANGE);
     *lengthP = value.len;
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/btle/btle.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/btle/btle.cpp
index afe6c77d8f..f004d86cb1 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/btle/btle.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/btle/btle.cpp
@@ -292,7 +292,7 @@ static void btle_handler(ble_evt_t *p_ble_evt)
 /*! @brief      Callback when an error occurs inside the SoftDevice */
 void assert_nrf_callback(uint16_t line_num, const uint8_t *p_file_name)
 {
-    ASSERT(false, (void) 0);
+    ASSERT_TRUE(false, (void) 0);
 }
 
 /*!
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/common/assertion.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/common/assertion.h
index c0bd8c0d66..71bacb3e81 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/common/assertion.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/common/assertion.h
@@ -125,7 +125,6 @@ static inline void debugger_breakpoint(void)
 //--------------------------------------------------------------------+
 // Logical Assert
 //--------------------------------------------------------------------+
-#define ASSERT(...)                      ASSERT_TRUE(__VA_ARGS__)
 #define ASSERT_TRUE(condition  , error)  ASSERT_DEFINE( , (condition), error, "%s", "evaluated to false")
 #define ASSERT_FALSE(condition , error)  ASSERT_DEFINE( ,!(condition), error, "%s", "evaluated to true")
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.cpp
index a2f59dd4da..f874bfefe5 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.cpp
@@ -96,7 +96,7 @@ ble_error_t nRF5xGap::setAdvertisingData(const GapAdvertisingData &advData, cons
     //}
 
     /* Send advertising data! */
-    ASSERT(ERROR_NONE ==
+    ASSERT_TRUE(ERROR_NONE ==
            sd_ble_gap_adv_data_set(advData.getPayload(),
                                    advData.getPayloadLen(),
                                    scanResponse.getPayload(),
@@ -105,7 +105,7 @@ ble_error_t nRF5xGap::setAdvertisingData(const GapAdvertisingData &advData, cons
 
     /* Make sure the GAP Service appearance value is aligned with the
      *appearance from GapAdvertisingData */
-    ASSERT(ERROR_NONE == sd_ble_gap_appearance_set(advData.getAppearance()),
+    ASSERT_TRUE(ERROR_NONE == sd_ble_gap_appearance_set(advData.getAppearance()),
            BLE_ERROR_PARAM_OUT_OF_RANGE);
 
     /* ToDo: Perform some checks on the payload, for example the Scan Response can't */
@@ -273,7 +273,7 @@ ble_error_t nRF5xGap::stopScan(void) {
 ble_error_t nRF5xGap::stopAdvertising(void)
 {
     /* Stop Advertising */
-    ASSERT(ERROR_NONE == sd_ble_gap_adv_stop(), BLE_ERROR_PARAM_OUT_OF_RANGE);
+    ASSERT_TRUE(ERROR_NONE == sd_ble_gap_adv_stop(), BLE_ERROR_PARAM_OUT_OF_RANGE);
 
     state.advertising = 0;
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.h b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.h
index adb80851dd..cdcd9fa8fe 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.h
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGap.h
@@ -221,7 +221,7 @@ private:
      */
     void processRadioNotificationEvent(bool param) {
         radioNotificationCallbackParam = param;
-        radioNotificationTimeout.attach_us(this, &nRF5xGap::postRadioNotificationCallback, 0);
+        radioNotificationTimeout.attach_us(mbed::callback(this, &nRF5xGap::postRadioNotificationCallback), 0);
     }
     friend void radioNotificationStaticCallback(bool param); /* allow invocations of processRadioNotificationEvent() */
 
diff --git a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGattServer.cpp b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGattServer.cpp
index 4f4c562920..7d079855cb 100644
--- a/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGattServer.cpp
+++ b/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5/source/nRF5xGattServer.cpp
@@ -52,7 +52,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
     nordicUUID = custom_convert_to_nordic_uuid(service.getUUID());
 
     uint16_t serviceHandle;
-    ASSERT( ERROR_NONE ==
+    ASSERT_TRUE( ERROR_NONE ==
             sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY,
                                      &nordicUUID,
                                      &serviceHandle),
@@ -88,7 +88,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
             }
         }
 
-        ASSERT ( ERROR_NONE ==
+        ASSERT_TRUE ( ERROR_NONE ==
                  custom_add_in_characteristic(BLE_GATT_HANDLE_INVALID,
                                               &nordicUUID,
                                               p_char->getProperties(),
@@ -123,7 +123,7 @@ ble_error_t nRF5xGattServer::addService(GattService &service)
 
             nordicUUID = custom_convert_to_nordic_uuid(p_desc->getUUID());
 
-            ASSERT(ERROR_NONE ==
+            ASSERT_TRUE(ERROR_NONE ==
                    custom_add_in_descriptor(BLE_GATT_HANDLE_INVALID,
                                             &nordicUUID,
                                             p_desc->getValuePtr(),
@@ -177,7 +177,7 @@ ble_error_t nRF5xGattServer::read(Gap::Handle_t connectionHandle, GattAttribute:
         .p_value = buffer,
     };
 
-    ASSERT( ERROR_NONE ==
+    ASSERT_TRUE( ERROR_NONE ==
             sd_ble_gatts_value_get(connectionHandle, attributeHandle, &value),
             BLE_ERROR_PARAM_OUT_OF_RANGE);
     *lengthP = value.len;
diff --git a/hal/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/nrf_delay.h b/hal/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/nrf_delay.h
index 4ce34e15e1..be4b9f4e15 100644
--- a/hal/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/nrf_delay.h
+++ b/hal/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/nrf_delay.h
@@ -45,7 +45,7 @@ __ASM (
        " BNE loop\n\t");
 }
 #elif defined   (  __GNUC__  )
-__INLINE static void nrf_delay_us(uint32_t volatile number_of_us)
+static __INLINE void nrf_delay_us(uint32_t volatile number_of_us)
 {
     do 
     {
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c b/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c
index 35ad304b85..8e745ba6c3 100755
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/spi_api.c
@@ -32,7 +32,7 @@ extern volatile i2c_spi_peripheral_t i2c1_spi1_peripheral;
 
 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
 {
-    SPIName spi;
+    SPIName spi = SPI_0;
     
     if (ssel == NC && i2c0_spi0_peripheral.usage == I2C_SPI_PERIPHERAL_FOR_SPI &&
             i2c0_spi0_peripheral.sda_mosi == (uint8_t)mosi &&
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c b/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c
index bdbb3abddb..0781f1689b 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c
@@ -588,6 +588,4 @@ uint32_t os_tick_val(void) {
 
         return clock_cycles_by_tick - ((current_counter - next_tick_cc_value) % clock_cycles_by_tick);
     }
-
-    return 0;
 }
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/ble/peer_manager/pm_buffer.c b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/ble/peer_manager/pm_buffer.c
index 20ea66b521..f185b5358e 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/ble/peer_manager/pm_buffer.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/ble/peer_manager/pm_buffer.c
@@ -100,7 +100,7 @@ uint8_t pm_buffer_block_acquire(pm_buffer_t * p_buffer, uint32_t n_blocks)
             {
                 first_locked_mutex = i;
             }
-            if ((i - first_locked_mutex + 1) == n_blocks)
+            if ((i - first_locked_mutex + 1) >= 0 && ((uint32_t) (i - first_locked_mutex + 1)) == n_blocks)
             {
                 return first_locked_mutex;
             }
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/drivers_nrf/delay/nrf_delay.h b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/drivers_nrf/delay/nrf_delay.h
index c68bd9a941..a9b110b092 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/drivers_nrf/delay/nrf_delay.h
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/drivers_nrf/delay/nrf_delay.h
@@ -159,8 +159,8 @@ __STATIC_INLINE void nrf_delay_us(uint32_t volatile number_of_us)
 
 #elif defined ( __GNUC__ )
 
-static void __INLINE nrf_delay_us(uint32_t volatile number_of_us) __attribute__((always_inline));
-static void __INLINE nrf_delay_us(uint32_t volatile number_of_us)
+static __INLINE void nrf_delay_us(uint32_t volatile number_of_us) __attribute__((always_inline));
+static __INLINE void nrf_delay_us(uint32_t volatile number_of_us)
 {
 register uint32_t delay __ASM ("r0") = number_of_us;
 __ASM volatile (
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/pwm/app_pwm.c b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/pwm/app_pwm.c
index 83ad686cbb..760b410f20 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/pwm/app_pwm.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/pwm/app_pwm.c
@@ -375,10 +375,10 @@ static void pwm_transition_n_to_m(app_pwm_t const * const p_instance,
 
 #ifdef NRF52
     if (ticks + ((nrf_timer_frequency_get(p_instance->p_timer->p_reg) == 
-        (m_use_ppi_delay_workaround ? NRF_TIMER_FREQ_8MHz : NRF_TIMER_FREQ_16MHz) ) ? 1 : 0)
+        (m_use_ppi_delay_workaround ? NRF_TIMER_FREQ_8MHz : NRF_TIMER_FREQ_16MHz) ) ? 1U : 0U)
         < p_ch_cb->pulsewidth)
 #else
-    if (ticks + ((nrf_timer_frequency_get(p_instance->p_timer->p_reg) == NRF_TIMER_FREQ_16MHz) ? 1 : 0)
+    if (ticks + ((nrf_timer_frequency_get(p_instance->p_timer->p_reg) == NRF_TIMER_FREQ_16MHz) ? 1U : 0U)
         < p_ch_cb->pulsewidth)
 #endif
     {
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/util/app_util_platform.h b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/util/app_util_platform.h
index 9eb20b7e43..0d082e2e65 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/util/app_util_platform.h
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/sdk/libraries/util/app_util_platform.h
@@ -111,10 +111,6 @@ typedef enum
 #define EXTERNAL_INT_VECTOR_OFFSET 16
 /**@endcond */
 
-#ifndef PACKED
-    #define PACKED(TYPE) __packed TYPE
-#endif
-
 void app_util_critical_region_enter (uint8_t *p_nested);
 void app_util_critical_region_exit (uint8_t nested);
 
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/serial_api.c b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/serial_api.c
index d1a0fe6218..8589cd4c62 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/serial_api.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/serial_api.c
@@ -310,7 +310,7 @@ void serial_init(serial_t *obj, PinName tx, PinName rx) {
         nrf_uart_configure(UART_INSTANCE, UART_CB.parity, UART_CB.hwfc);
         if (UART_CB.hwfc == NRF_UART_HWFC_ENABLED) {
             serial_set_flow_control(obj, FlowControlRTSCTS,
-                UART_CB.pselrts, UART_CB.pselcts);
+                (PinName) UART_CB.pselrts, (PinName) UART_CB.pselcts);
         }
         nrf_uart_enable(UART_INSTANCE);
 
diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/us_ticker.c b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/us_ticker.c
index da93ae5a5a..35045fdb3f 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/us_ticker.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/us_ticker.c
@@ -284,7 +284,7 @@ US_TICKER_HANDLER
     push {r3, lr}
     bl common_rtc_irq_handler
     pop {r3, pc}
-    nop /* padding */
+    ; ALIGN ;
 }
 
 #elif defined (__GNUC__)        /* GNU Compiler */