diff --git a/targets/esp8266/Makefile.esp8266 b/targets/esp8266/Makefile.esp8266
index e400d4dade..cea2c02d95 100644
--- a/targets/esp8266/Makefile.esp8266
+++ b/targets/esp8266/Makefile.esp8266
@@ -48,10 +48,10 @@ JERRY_BUILD_FILES := $(SRCPATH)/jerry_extapi.c
 JERRY_BUILD_FILES := $(JERRY_BUILD_FILES);$(SRCPATH)/jerry_run.c
 
 
-.PHONY: jerry js2c mbed check-env flash clean
+.PHONY: jerry js2c mkbin check-env flash clean
 
 
-all: check-env jerry js2c mbed
+all: check-env jerry js2c mkbin
 
 
 jerry:
@@ -83,7 +83,7 @@ js2c:
 	cd targets/esp8266; ../tools/js2c.py
 
 
-mbed:
+mkbin:
 	cd targets/esp8266; \
 	 make clean; \
 	 BOOT=new APP=1 SPI_SPEED=40 SPI_MODE=QIO SPI_SIZE_MAP=3 make; \
diff --git a/targets/esp8266/include/jerry_extapi.h b/targets/esp8266/include/jerry_extapi.h
index f10d527fd1..856a79c587 100644
--- a/targets/esp8266/include/jerry_extapi.h
+++ b/targets/esp8266/include/jerry_extapi.h
@@ -24,14 +24,14 @@
 
 #define API_DATA_IS_FUNCTION(val_p) \
     (API_DATA_IS_OBJECT(val_p) && \
-     jerry_api_is_function((val_p)->v_object))
+     jerry_api_is_function((val_p)->u.v_object))
 
 #define JS_VALUE_TO_NUMBER(val_p) \
     ((val_p)->type == JERRY_API_DATA_TYPE_FLOAT32 ? \
-     (double) ((val_p)->v_float32) : \
+     (double) ((val_p)->u.v_float32) : \
      (val_p)->type == JERRY_API_DATA_TYPE_FLOAT64 ? \
-       (double) ((val_p)->v_float64) : \
-       (double) ((val_p)->v_uint32))
+       (double) ((val_p)->u.v_float64) : \
+       (double) ((val_p)->u.v_uint32))
 
 
 #ifdef __cplusplus
diff --git a/targets/esp8266/readme.md b/targets/esp8266/readme.md
index 44c5f2c590..396677cf3f 100644
--- a/targets/esp8266/readme.md
+++ b/targets/esp8266/readme.md
@@ -1,8 +1,9 @@
 ### About
 
 Files in this folder (embedding/esp8266) are copied from
-examples/project_template of esp_iot_rtos_sdk and modified for JerryScript.
-You can view online from [this](https://github.com/espressif/esp_iot_rtos_sdk/tree/master/examples/project_template) page.
+`examples/project_template` of `esp_iot_rtos_sdk` and modified for JerryScript.
+You can view online from
+[this](https://github.com/espressif/esp_iot_rtos_sdk/tree/master/examples/project_template) page.
 
 
 ### How to build JerryScript for ESP8266
@@ -21,7 +22,9 @@ Below is a summary after SDK patch is applied.
 
 ```
 cd ~/harmony/jerryscript
+# clean build
 make -f ./targets/esp8266/Makefile.esp8266 clean
+# or just normal build
 make -f ./targets/esp8266/Makefile.esp8266
 ```
 
@@ -29,7 +32,7 @@ Output files should be placed at $BIN_PATH
 
 #### 4. Flashing for ESP8266 ESP-01 board (WiFi Module)
 
-Steps are for ESP8266 ESP-01(WiFi) board. Others may vary.
+Steps are for `ESP8266 ESP-01(WiFi)` board. Others may vary.
 Refer http://www.esp8266.com/wiki/doku.php?id=esp8266-module-family page.
 
 ##### 4.1 GPIO0 and GPIO2
diff --git a/targets/esp8266/source/jerry_extapi.c b/targets/esp8266/source/jerry_extapi.c
index c4fb8ae969..9698929cb9 100644
--- a/targets/esp8266/source/jerry_extapi.c
+++ b/targets/esp8266/source/jerry_extapi.c
@@ -41,12 +41,12 @@ NAME ## _handler (const jerry_api_object_t * function_obj_p __UNSED__, \
 #define REGISTER_HANDLER(NAME) \
   register_native_function ( # NAME, NAME ## _handler)
 
-//-----------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
 
 DELCARE_HANDLER(assert) {
   if (args_cnt == 1
       && args_p[0].type == JERRY_API_DATA_TYPE_BOOLEAN
-      && args_p[0].v_bool == true)
+      && args_p[0].u.v_bool == true)
   {
     printf (">> Jerry assert true\r\n");
     return true;
@@ -65,13 +65,13 @@ DELCARE_HANDLER(print) {
     printf(">> print(%d) :", (int)args_cnt);
     for (cc=0; cc<args_cnt; cc++)
     {
-      if (args_p[cc].type == JERRY_API_DATA_TYPE_STRING && args_p[cc].v_string)
+      if (args_p[cc].type == JERRY_API_DATA_TYPE_STRING && args_p[cc].u.v_string)
       {
         static char buffer[128];
-        int length, maxlength;
-        length = -jerry_api_string_to_char_buffer (args_p[0].v_string, NULL, 0);
+        jerry_api_size_t length, maxlength;
+        length = -jerry_api_string_to_char_buffer (args_p[0].u.v_string, NULL, 0);
         maxlength  = MIN(length, 126);
-        jerry_api_string_to_char_buffer (args_p[cc].v_string,
+        jerry_api_string_to_char_buffer (args_p[cc].u.v_string,
                                          (jerry_api_char_t *) buffer,
                                          maxlength);
         *(buffer + length) = 0;
@@ -88,15 +88,15 @@ DELCARE_HANDLER(print) {
 }
 
 
-//-----------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
 
 DELCARE_HANDLER(gpio_dir) {
+  int port, value;
   if (args_cnt < 2)
   {
     return false;
   }
 
-  int port, value;
   port = (int)JS_VALUE_TO_NUMBER (&args_p[0]);
   value = (int)JS_VALUE_TO_NUMBER (&args_p[1]);
 
@@ -106,12 +106,12 @@ DELCARE_HANDLER(gpio_dir) {
 } /* gpio_dir_handler */
 
 DELCARE_HANDLER(gpio_set) {
+  int port, value;
   if (args_cnt < 2)
   {
     return false;
   }
 
-  int port, value;
   port = (int)JS_VALUE_TO_NUMBER (&args_p[0]);
   value = (int)JS_VALUE_TO_NUMBER (&args_p[1]);
 
@@ -122,24 +122,25 @@ DELCARE_HANDLER(gpio_set) {
 
 
 DELCARE_HANDLER(gpio_get) {
+  int port, value;
   if (args_cnt < 1)
   {
     return false;
   }
 
-  int port, value;
   port = (int)JS_VALUE_TO_NUMBER (&args_p[0]);
 
   value = native_gpio_get (port) ? 1 : 0;
 
   ret_val_p->type = JERRY_API_DATA_TYPE_FLOAT64;
-  ret_val_p->v_float64 = (double)value;
+  ret_val_p->u.v_float64 = (double)value;
 
   return true;
 } /* gpio_dir_handler */
 
 
-//-----------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
+
 static bool
 register_native_function (const char* name,
                           jerry_external_handler_t handler)
@@ -163,7 +164,7 @@ register_native_function (const char* name,
 
   jerry_api_acquire_object (reg_func_p);
   reg_value.type = JERRY_API_DATA_TYPE_OBJECT;
-  reg_value.v_object = reg_func_p;
+  reg_value.u.v_object = reg_func_p;
 
   bok = jerry_api_set_object_field_value (global_obj_p,
                                           (jerry_api_char_t *)name,
@@ -182,7 +183,7 @@ register_native_function (const char* name,
 }
 
 
-//-----------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
 
 void js_register_functions (void)
 {
diff --git a/targets/esp8266/source/jerry_run.c b/targets/esp8266/source/jerry_run.c
index 6ecda39f0c..cb483bdc82 100644
--- a/targets/esp8266/source/jerry_run.c
+++ b/targets/esp8266/source/jerry_run.c
@@ -24,19 +24,20 @@
 static const char* fn_sys_loop_name = "sysloop";
 
 
-//-----------------------------------------------------------------------------
+/*---------------------------------------------------------------------------*/
 
 int js_entry (const char *source_p, const size_t source_size)
 {
   const jerry_api_char_t *jerry_src = (const jerry_api_char_t *) source_p;
   jerry_completion_code_t ret_code = JERRY_COMPLETION_CODE_OK;
   jerry_flag_t flags = JERRY_FLAG_EMPTY;
+  jerry_api_object_t *err_obj_p = NULL;
 
   jerry_init (flags);
 
   js_register_functions ();
 
-  if (!jerry_parse (jerry_src, source_size))
+  if (!jerry_parse ((jerry_api_char_t *)jerry_src, source_size, &err_obj_p))
   {
     printf ("Error: jerry_parse failed\r\n");
     ret_code = JERRY_COMPLETION_CODE_UNHANDLED_EXCEPTION;
@@ -45,7 +46,8 @@ int js_entry (const char *source_p, const size_t source_size)
   {
     if ((flags & JERRY_FLAG_PARSE_ONLY) == 0)
     {
-      ret_code = jerry_run ();
+      jerry_api_value_t err_value = jerry_api_create_void_value ();
+      ret_code = jerry_run (&err_value);
     }
   }
 
@@ -72,6 +74,9 @@ int js_loop (uint32_t ticknow)
 {
   jerry_api_object_t *global_obj_p;
   jerry_api_value_t sysloop_func;
+  jerry_api_value_t* val_args;
+  uint16_t val_argv;
+  jerry_api_value_t res;
   bool is_ok;
 
   global_obj_p = jerry_api_get_global ();
@@ -93,16 +98,12 @@ int js_loop (uint32_t ticknow)
     return -2;
   }
 
-  jerry_api_value_t* val_args;
-  uint16_t val_argv;
-
   val_argv = 1;
   val_args = (jerry_api_value_t*)malloc (sizeof (jerry_api_value_t) * val_argv);
   val_args[0].type = JERRY_API_DATA_TYPE_UINT32;
-  val_args[0].v_uint32 = ticknow;
+  val_args[0].u.v_uint32 = ticknow;
 
-  jerry_api_value_t res;
-  is_ok = jerry_api_call_function (sysloop_func.v_object,
+  is_ok = jerry_api_call_function (sysloop_func.u.v_object,
                                    global_obj_p,
                                    &res,
                                    val_args,
diff --git a/targets/esp8266/user/jerry_port.c b/targets/esp8266/user/jerry_port.c
index a17e459562..2c3fffe33c 100644
--- a/targets/esp8266/user/jerry_port.c
+++ b/targets/esp8266/user/jerry_port.c
@@ -1,4 +1,4 @@
-/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
+/* Copyright 2014-2016 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -46,11 +46,45 @@ int jerry_port_errormsg (const char* format, ...)
   return count;
 }
 
+
+/** exit - cause normal process termination  */
 void exit (int status)
 {
-  printf ("!!!! EXIT: %d\n", status);
   while (true)
   {
-    ;
   }
 } /* exit */
+
+/** abort - cause abnormal process termination  */
+void abort (void)
+{
+  while (true)
+  {
+  }
+} /* abort */
+
+/**
+ * fwrite
+ *
+ * @return number of bytes written
+ */
+size_t
+fwrite (const void *ptr, /**< data to write */
+        size_t size, /**< size of elements to write */
+        size_t nmemb, /**< number of elements */
+        FILE *stream) /**< stream pointer */
+{
+  return size * nmemb;
+} /* fwrite */
+
+/**
+ * This function can get the time as well as a timezone.
+ *
+ * @return 0 if success, -1 otherwise
+ */
+int
+gettimeofday (void *tp,  /**< struct timeval */
+              void *tzp) /**< struct timezone */
+{
+  return -1;
+} /* gettimeofday */
diff --git a/targets/esp8266/user/user_main.c b/targets/esp8266/user/user_main.c
index 925c994498..c53a43aa9e 100644
--- a/targets/esp8266/user/user_main.c
+++ b/targets/esp8266/user/user_main.c
@@ -98,7 +98,6 @@ void jerry_task(void *pvParameters) {
  */
 void ICACHE_FLASH_ATTR user_init(void)
 {
-  const portTickType onesec = 1000 / portTICK_RATE_MS;
   uart_div_modify(UART0, UART_CLK_FREQ / (BIT_RATE_115200));
 
   show_free_mem(0);