diff --git a/.gitignore b/.gitignore
index bab9c0778..def6aaec1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@ nbproject
 *~
 js.files
 core
+**.orig
 
 # ctags and ID database
 tags
diff --git a/Makefile.mak b/Makefile.mak
index 6bdfbe040..ec77a95d2 100644
--- a/Makefile.mak
+++ b/Makefile.mak
@@ -110,7 +110,7 @@ CFLAGS_CORTEXM4 ?= -mlittle-endian -mcpu=cortex-m4 -march=armv7e-m -mthumb \
 # Common
 #
 
-CFLAGS_COMMON ?= $(INCLUDES) -std=c99 -fsanitize=address -fdiagnostics-color=always 
+CFLAGS_COMMON ?= $(INCLUDES) -std=c99 #-fsanitize=address -fdiagnostics-color=always 
 
 LDFLAGS ?= 
 
diff --git a/src/generated.h b/src/generated.h
index fae8816bc..68e831091 100644
--- a/src/generated.h
+++ b/src/generated.h
@@ -15,17 +15,6 @@
 
 #include "globals.h"
 
-static const char* generated_source __unused = ""
-"while (true) {\n"
-"LEDToggle (LED3);\n"
-"LEDToggle (LED6);\n"
-"LEDToggle (LED7);\n"
-"LEDToggle (LED4);\n"
-"LEDToggle (LED10);\n"
-"LEDToggle (LED8);\n"
-"LEDToggle (LED9);\n"
-"LEDToggle (LED5);\n"
-"\n"
-"wait(500);\n"
-"}\n"
+static const char* generated_source  = ""
+"LEDToggle (14);\n"
 ;
diff --git a/src/libcoreint/interpreter.c b/src/libcoreint/interpreter.c
index 821cb9328..dfc9a8b3b 100644
--- a/src/libcoreint/interpreter.c
+++ b/src/libcoreint/interpreter.c
@@ -13,8 +13,12 @@
  * limitations under the License.
  */
 
+#include "deserializer.h"
+#include "ecma-globals.h"
 #include "ecma-helpers.h"
+#include "globals.h"
 #include "interpreter.h"
+#include "jerry-libc.h"
 
 #define INIT_OP_FUNC(name) [ __op__idx_##name ] = opfunc_##name,
 static const opfunc __opfuncs[LAST_OP] = {
@@ -42,15 +46,17 @@ run_int (void)
 {
   JERRY_ASSERT( __program != NULL );
 
-  struct __int_data int_data;
-  int_data.pos = 0;
-  int_data.this_binding_p = NULL;
-  int_data.lex_env_p = ecma_create_lexical_environment( NULL,
-                                                        ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE);
+  const int start_pos = 0;
+  ecma_object_t *this_binding_p = NULL;
+  ecma_object_t *lex_env_p = ecma_create_lexical_environment (NULL,
+                                                              ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE);
   FIXME( Strict mode );
-  int_data.is_strict = false;
+  const bool is_strict = false;
 
-  ecma_completion_value_t completion = run_int_from_pos( &int_data);
+  ecma_completion_value_t completion = run_int_from_pos (start_pos,
+                                                         this_binding_p,
+                                                         lex_env_p,
+                                                         is_strict);
 
   switch ( (ecma_completion_type_t)completion.type )
   {
@@ -82,16 +88,43 @@ run_int (void)
 }
 
 ecma_completion_value_t
-run_int_from_pos (struct __int_data *int_data)
+run_int_from_pos (int start_pos,
+                  ecma_object_t *this_binding_p,
+                  ecma_object_t *lex_env_p,
+                  bool is_strict)
 {
   ecma_completion_value_t completion;
 
+  const OPCODE *curr = &__program[start_pos];
+  JERRY_ASSERT( curr->op_idx == __op__idx_reg_var_decl );
+
+  const T_IDX min_reg_num = curr->data.reg_var_decl.min;
+  const T_IDX max_reg_num = curr->data.reg_var_decl.max;
+  JERRY_ASSERT( max_reg_num >= min_reg_num );
+
+  const uint32_t regs_num = (uint32_t) (max_reg_num - min_reg_num + 1);
+
+  ecma_value_t regs[ regs_num ];
+
+  /* memseting with zero initializes each 'register' to empty value */
+  __memset (regs, 0, sizeof(regs));
+  JERRY_ASSERT( ecma_is_value_empty( regs[0]) );
+
+  struct __int_data int_data;
+  int_data.pos = start_pos + 1;
+  int_data.this_binding_p = this_binding_p;
+  int_data.lex_env_p = lex_env_p;
+  int_data.is_strict = is_strict;
+  int_data.min_reg_num = min_reg_num;
+  int_data.max_reg_num = max_reg_num;
+  int_data.regs_p = regs;
+
   while ( true )
     {
       do
         {
-          const OPCODE *curr = &__program[int_data->pos];
-          completion = __opfuncs[curr->op_idx](*curr, int_data);
+          const OPCODE *curr = &__program[int_data.pos];
+          completion = __opfuncs[curr->op_idx](*curr, &int_data);
 
           JERRY_ASSERT( !ecma_is_completion_value_normal( completion)
                         || ecma_is_completion_value_normal_simple_value(completion,
@@ -111,6 +144,13 @@ run_int_from_pos (struct __int_data *int_data)
           continue;
         }
 
+      for ( uint32_t reg_index = 0;
+            reg_index < regs_num;
+            reg_index++ )
+        {
+          ecma_free_value( regs[ reg_index ] );
+        }
+
       return completion;
     }
 }
@@ -128,18 +168,19 @@ try_get_string_by_idx(T_IDX idx, /**< literal id */
 {
   TODO( Actual string literal retrievement );
 
-  ssize_t req_length = 2; // TODO
-
-  JERRY_ASSERT( idx < 'z' - 'a' + 1 );
+  const ecma_char_t *str_p = deserialize_string_by_id( idx);
+  JERRY_ASSERT( str_p != NULL );
+  
+  FIXME( strlen for ecma_char_t );
+  ssize_t req_length = (ssize_t)__strlen( (const char*)str_p) + 1;
 
   if ( buffer_size < req_length )
   {
     return -req_length;
   }
 
-  // TODO
-  buffer_p[0] = (ecma_char_t) ('a' + idx);
-  buffer_p[1] = 0;
+  FIXME( strncpy for ecma_char_t );
+  __strncpy( (char*)buffer_p, (const char*)str_p, (size_t)req_length);
 
   return req_length;
 } /* try_get_string_by_idx */
@@ -154,5 +195,8 @@ get_number_by_idx(T_IDX idx) /**< literal id */
 {
   TODO( Actual number literal retrievement );
 
-  return (ecma_number_t)idx;
+  FIXME( /* conversion of value returned from deserialize_num_by_id to ecma_number_t */ );
+  ecma_number_t num = (ecma_number_t) deserialize_num_by_id( idx);
+
+  return num;
 } /* get_number_by_idx */
diff --git a/src/libcoreint/interpreter.h b/src/libcoreint/interpreter.h
index 5825b25eb..253b77565 100644
--- a/src/libcoreint/interpreter.h
+++ b/src/libcoreint/interpreter.h
@@ -26,11 +26,17 @@ struct __int_data
   ecma_object_t *this_binding_p; /**< this binding for current context */
   ecma_object_t *lex_env_p; /**< current lexical environment */
   bool is_strict; /**< is current code execution mode strict? */
+  T_IDX min_reg_num; /**< minimum idx used for register identification */
+  T_IDX max_reg_num; /**< maximum idx used for register identification */
+  ecma_value_t *regs_p; /**< register variables */
 };
 
 void init_int (const OPCODE* program_p);
 bool run_int (void);
-ecma_completion_value_t run_int_from_pos (struct __int_data *);
+ecma_completion_value_t run_int_from_pos (int start_pos,
+                                          ecma_object_t *this_binding_p,
+                                          ecma_object_t *lex_env_p,
+                                          bool is_strict);
 
 ssize_t try_get_string_by_idx( T_IDX idx, ecma_char_t *buffer_p, ssize_t buffer_size);
 ecma_number_t get_number_by_idx(T_IDX idx);
diff --git a/src/libcoreint/opcodes.c b/src/libcoreint/opcodes.c
index af9357c26..783ab449f 100644
--- a/src/libcoreint/opcodes.c
+++ b/src/libcoreint/opcodes.c
@@ -25,6 +25,10 @@
 #include "mem-heap.h"
 #include "opcodes.h"
 
+#include "actuators.h"
+#include "common-io.h"
+#include "sensors.h"
+
 /**
  * Note:
  *      The note describes exception handling in opcode handlers that perform operations,
@@ -183,27 +187,42 @@ get_variable_value(struct __int_data *int_data, /**< interpreter context */
                    bool do_eval_or_arguments_check) /** run 'strict eval or arguments reference' check
                                                         See also: do_strict_eval_arguments_check */
 {
-  string_literal_copy var_name;
-  ecma_reference_t ref;
   ecma_completion_value_t ret_value;
 
-  init_string_literal_copy( var_idx, &var_name);
-  ref = ecma_op_get_identifier_reference( int_data->lex_env_p,
-                                       var_name.str_p,
-                                       int_data->is_strict);
+  if ( var_idx >= int_data->min_reg_num
+       && var_idx <= int_data->max_reg_num )
+  {
+    ecma_value_t reg_value = int_data->regs_p[ var_idx - int_data->min_reg_num ];
 
-  if ( unlikely( do_eval_or_arguments_check
-                 && do_strict_eval_arguments_check( ref) ) )
+    JERRY_ASSERT( !ecma_is_value_empty( reg_value) );
+
+    ret_value = ecma_make_completion_value (ECMA_COMPLETION_TYPE_NORMAL,
+                                            ecma_copy_value( reg_value),
+                                            ECMA_TARGET_ID_RESERVED);
+  }
+  else
+  {
+    string_literal_copy var_name;
+    ecma_reference_t ref;
+
+    init_string_literal_copy( var_idx, &var_name);
+    ref = ecma_op_get_identifier_reference( int_data->lex_env_p,
+        var_name.str_p,
+        int_data->is_strict);
+
+    if ( unlikely( do_eval_or_arguments_check
+          && do_strict_eval_arguments_check( ref) ) )
     {
       ret_value = ecma_make_throw_value( ecma_new_standard_error( ECMA_ERROR_SYNTAX));
     }
-  else
+    else
     {
       ret_value = ecma_op_get_value( ref);
     }
 
-  ecma_free_reference( ref);
-  free_string_literal_copy( &var_name);
+    ecma_free_reference( ref);
+    free_string_literal_copy( &var_name);
+  }
 
   return ret_value;
 } /* get_variable_value */
@@ -219,26 +238,44 @@ set_variable_value(struct __int_data *int_data, /**< interpreter context */
                    T_IDX var_idx, /**< variable identifier */
                    ecma_value_t value) /**< value to set */
 {
-  string_literal_copy var_name;
-  ecma_reference_t ref;
   ecma_completion_value_t ret_value;
 
-  init_string_literal_copy( var_idx, &var_name);
-  ref = ecma_op_get_identifier_reference( int_data->lex_env_p,
-                                       var_name.str_p,
-                                       int_data->is_strict);
+  if ( var_idx >= int_data->min_reg_num
+       && var_idx <= int_data->max_reg_num )
+  {
+    ecma_value_t reg_value = int_data->regs_p[ var_idx - int_data->min_reg_num ];
 
-  if ( unlikely( do_strict_eval_arguments_check( ref) ) )
+    if ( !ecma_is_value_empty( reg_value) )
+    {
+      ecma_free_value( reg_value);
+    }
+
+    int_data->regs_p[ var_idx - int_data->min_reg_num ] = ecma_copy_value( value);
+
+    ret_value = ecma_make_empty_completion_value();
+  }
+  else
+  {
+    string_literal_copy var_name;
+    ecma_reference_t ref;
+
+    init_string_literal_copy( var_idx, &var_name);
+    ref = ecma_op_get_identifier_reference( int_data->lex_env_p,
+        var_name.str_p,
+        int_data->is_strict);
+
+    if ( unlikely( do_strict_eval_arguments_check( ref) ) )
     {
       ret_value = ecma_make_throw_value( ecma_new_standard_error( ECMA_ERROR_SYNTAX));
     }
-  else
+    else
     {
       ret_value = ecma_op_put_value( ref, value);
     }
 
-  ecma_free_reference( ref);
-  free_string_literal_copy( &var_name);
+    ecma_free_reference( ref);
+    free_string_literal_copy( &var_name);
+  }
 
   return ret_value;
 } /* set_variable_value */
@@ -376,20 +413,23 @@ do_number_arithmetic(struct __int_data *int_data, /**< interpreter context */
     op(post_decr)                       \
     op(pre_incr)                        \
     op(pre_decr)                        \
-    op(reg_var_decl)                   
+    static char __unused unimplemented_list_end
 
 #define DEFINE_UNIMPLEMENTED_OP(op) \
   ecma_completion_value_t opfunc_ ## op(OPCODE opdata, struct __int_data *int_data) { \
     JERRY_UNIMPLEMENTED_REF_UNUSED_VARS( opdata, int_data); \
   }
-OP_UNIMPLEMENTED_LIST(DEFINE_UNIMPLEMENTED_OP)
+OP_UNIMPLEMENTED_LIST(DEFINE_UNIMPLEMENTED_OP);
 #undef DEFINE_UNIMPLEMENTED_OP
 
 ecma_completion_value_t
 opfunc_call_1 (OPCODE opdata __unused, struct __int_data *int_data)
-{
+{  
+  ecma_completion_value_t ret_value;
+  ret_value = ecma_make_empty_completion_value ();
+
 #ifdef __HOST
-  __printf ("%d::op_call_1:idx:%d:%d\n",
+  __printf ("%d::op_call_1:idx:%d:%d\t",
           int_data->pos,
           opdata.data.call_1.name_lit_idx,
           opdata.data.call_1.arg1_lit_idx);
@@ -397,8 +437,27 @@ opfunc_call_1 (OPCODE opdata __unused, struct __int_data *int_data)
 
   int_data->pos++;
 
-  // FIXME
-  return ecma_make_empty_completion_value();
+  string_literal_copy str_value;
+  init_string_literal_copy( opdata.data.call_1.name_lit_idx, &str_value);
+
+#ifdef __HOST
+  __printf("%s\n", str_value.str_p);
+#endif
+  
+  if (!__strcmp ((const char*)str_value.str_p, "LEDToggle"))
+  {
+    TRY_CATCH (cond_value, get_variable_value (int_data, opdata.data.call_1.arg1_lit_idx, false), ret_value);
+    JERRY_ASSERT(cond_value.value.value_type == ECMA_TYPE_NUMBER );
+    ecma_number_t * num_p = (ecma_number_t*)ecma_get_pointer(cond_value.value.value);
+    uint32_t int_num = (uint32_t)*num_p;
+    led_blink_once (int_num);
+    ret_value = ecma_make_empty_completion_value ();
+    FINALIZE (cond_value);
+  }
+
+  free_string_literal_copy (&str_value);
+
+  return ret_value;
 }
 
 /**
@@ -808,6 +867,18 @@ opfunc_remainder(OPCODE opdata, /**< operation data */
   return ret_value;
 } /* opfunc_remainder */
 
+/**
+ * 'Register variable declaration' opcode handler.
+ *
+ * The opcode is meta-opcode that is not supposed to be executed.
+ */
+ecma_completion_value_t
+opfunc_reg_var_decl(OPCODE opdata __unused, /**< operation data */
+                    struct __int_data *int_data __unused) /**< interpreter context */
+{
+  JERRY_UNREACHABLE();
+} /* opfunc_reg_var_decl */
+
 /**
  * 'Variable declaration' opcode handler.
  *
@@ -819,25 +890,25 @@ opfunc_remainder(OPCODE opdata, /**< operation data */
  */
 ecma_completion_value_t
 opfunc_var_decl(OPCODE opdata, /**< operation data */
-                struct __int_data *int_data __unused) /**< interpreter context */
+                struct __int_data *int_data) /**< interpreter context */
 {
   string_literal_copy variable_name;
   init_string_literal_copy( opdata.data.var_decl.variable_name, &variable_name);
 
-  if ( ecma_is_completion_value_normal_false( ecma_op_has_binding( int_data->lex_env_p,
-                                                             variable_name.str_p)) )
+  if ( ecma_is_completion_value_normal_false( ecma_op_has_binding (int_data->lex_env_p,
+                                                                   variable_name.str_p)) )
   {
     FIXME( Pass configurableBindings that is true if and only if current code is eval code );
-    ecma_op_create_mutable_binding( int_data->lex_env_p,
-                                 variable_name.str_p,
-                                 false);
+    ecma_op_create_mutable_binding (int_data->lex_env_p,
+                                    variable_name.str_p,
+                                    false);
 
     /* Skipping SetMutableBinding as we have already checked that there were not
      * any binding with specified name in current lexical environment 
      * and CreateMutableBinding sets the created binding's value to undefined */
-    JERRY_ASSERT( ecma_is_completion_value_normal_simple_value( ecma_op_get_binding_value( int_data->lex_env_p,
-                                                                                        variable_name.str_p,
-                                                                                        true),
+    JERRY_ASSERT( ecma_is_completion_value_normal_simple_value( ecma_op_get_binding_value (int_data->lex_env_p,
+                                                                                           variable_name.str_p,
+                                                                                           true),
                                                                 ECMA_SIMPLE_VALUE_UNDEFINED) );
   }
 
diff --git a/src/libecmaobjects/ecma-globals.h b/src/libecmaobjects/ecma-globals.h
index 61a58f586..39611a2e3 100644
--- a/src/libecmaobjects/ecma-globals.h
+++ b/src/libecmaobjects/ecma-globals.h
@@ -63,11 +63,11 @@ typedef enum {
  * Simple ecma-values
  */
 typedef enum {
+    ECMA_SIMPLE_VALUE_EMPTY, /**< empty value (see also: ECMA-262 v5, 8.9 Completion specification type) */
     ECMA_SIMPLE_VALUE_UNDEFINED, /**< undefined value */
     ECMA_SIMPLE_VALUE_NULL, /**< null value */
     ECMA_SIMPLE_VALUE_FALSE, /**< boolean false */
     ECMA_SIMPLE_VALUE_TRUE, /**< boolean true */
-    ECMA_SIMPLE_VALUE_EMPTY, /**< empty value (see also: ECMA-262 v5, 8.9 Completion specification type) */
     ECMA_SIMPLE_VALUE_ARRAY_REDIRECT, /**< special value for an array's elements that exists,
                                            but is stored directly in the array's property list
                                            (used for array elements with non-default attribute values) */
diff --git a/src/libecmaobjects/ecma-helpers-value.c b/src/libecmaobjects/ecma-helpers-value.c
index bb66c33a9..efa0a1155 100644
--- a/src/libecmaobjects/ecma-helpers-value.c
+++ b/src/libecmaobjects/ecma-helpers-value.c
@@ -26,6 +26,18 @@
 #include "ecma-helpers.h"
 #include "globals.h"
 
+/**
+ * Check if the value is empty.
+ *
+ * @return true - if the value contains implementation-defined empty simple value,
+ *         false - otherwise.
+ */
+bool
+ecma_is_value_empty( ecma_value_t value) /**< ecma-value */
+{
+  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_EMPTY );
+} /* ecma_is_value_empty */
+
 /**
  * Check if the value is undefined.
  *
diff --git a/src/libecmaobjects/ecma-helpers.h b/src/libecmaobjects/ecma-helpers.h
index db8e3e0ab..a72e84bec 100644
--- a/src/libecmaobjects/ecma-helpers.h
+++ b/src/libecmaobjects/ecma-helpers.h
@@ -42,6 +42,7 @@ extern void* ecma_decompress_pointer(uintptr_t compressed_pointer);
     (field) = ecma_compress_pointer( non_compressed_pointer) & ( ( 1u << ECMA_POINTER_FIELD_WIDTH ) - 1)
 
 /* ecma-helpers-value.c */
+extern bool ecma_is_value_empty( ecma_value_t value);
 extern bool ecma_is_value_undefined( ecma_value_t value);
 extern bool ecma_is_value_null( ecma_value_t value);
 extern bool ecma_is_value_boolean( ecma_value_t value);
diff --git a/src/libperipherals/actuators.c b/src/libperipherals/actuators.c
index 1fa50043a..bd66af889 100644
--- a/src/libperipherals/actuators.c
+++ b/src/libperipherals/actuators.c
@@ -13,20 +13,85 @@
  * limitations under the License.
  */
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpedantic"
+#pragma GCC diagnostic ignored "-Wsign-conversion"
+#ifdef __TARGET_MCU
+#include "stm32f4xx.h"
+#include "stm32f4xx_gpio.h"
+#include "stm32f4xx_rcc.h"
+#endif
+#pragma GCC diagnostic pop
+
 #include "actuators.h"
 #include "jerry-libc.h"
 
-void led_toggle(int led_id)
+#ifdef __TARGET_MCU
+
+void
+blink_once (uint32_t led)
 {
-  __printf("led_toogle: %d", led_id);
+  uint32_t pin = led;
+  uint32_t mode = (uint32_t)GPIO_Mode_OUT << (pin * 2);
+  uint32_t speed = (uint32_t)GPIO_Speed_100MHz << (pin * 2);
+  uint32_t type = (uint32_t)GPIO_OType_PP << pin;
+  uint32_t pullup = (uint32_t)GPIO_PuPd_NOPULL << (pin * 2);
+  
+  TODO (INITIALIZE ONCE);
+  //
+  //  Initialise the peripheral clock.
+  //
+  RCC->AHB1ENR |= RCC_AHB1Periph_GPIOD;
+  //
+  //  Initilaise the GPIO port.
+  //
+  volatile GPIO_TypeDef* gpio = GPIOD;
+
+  gpio->MODER |= mode;
+  gpio->OSPEEDR |= speed;
+  gpio->OTYPER |= type;
+  gpio->PUPDR |= pullup;
+  //
+  //  Toggle the selected LED indefinitely.
+  //
+  int index;
+  
+  int dot = 600000;
+  int dash = dot * 3;
+  
+  while (1)
+  {
+    gpio->BSRRL = (uint16_t) (1 << pin); for (index = 0; index < dot; index++); gpio->BSRRH = (uint16_t) (1 << pin); for (index = 0; index < dash; index++);
+    gpio->BSRRL = (uint16_t) (1 << pin); for (index = 0; index < dot; index++); gpio->BSRRH = (uint16_t) (1 << pin); for (index = 0; index < dash; index++);
+    gpio->BSRRL = (uint16_t) (1 << pin); for (index = 0; index < dot; index++); gpio->BSRRH = (uint16_t) (1 << pin); for (index = 0; index < dash; index++);
+
+    for (index = 0; index < dash * 7; index++);
+  }
+}
+#endif
+
+void led_toggle(uint32_t led_id)
+{
+  __printf("led_toggle: %d\n", led_id);
 }
 
-void led_on(int led_id)
+void led_on(uint32_t led_id)
 {
-  __printf("led_on: %d", led_id);
+  __printf("led_on: %d\n", led_id);
 }
 
-void led_off(int led_id)
+void led_off(uint32_t led_id)
 {
-  __printf("led_off: %d", led_id);
+  __printf("led_off: %d\n", led_id);
+}
+
+void led_blink_once(uint32_t led_id)
+{
+#ifdef __HOST
+  __printf("led_blink_once: %d\n", led_id);
+#endif
+
+#ifdef __TARGET_MCU
+  blink_once(led_id);
+#endif
 }
diff --git a/src/libperipherals/actuators.h b/src/libperipherals/actuators.h
index 40114e69f..5700e00d6 100644
--- a/src/libperipherals/actuators.h
+++ b/src/libperipherals/actuators.h
@@ -16,15 +16,19 @@
 #ifndef ACTUATORS_H
 #define	ACTUATORS_H
 
+#include "globals.h"
+
 // STM32 F4
 #define LED_GREEN      12
 #define LED_ORANGE     13
 #define LED_RED        14
 #define LED_BLUE       15
 
-void led_toggle(int);
-void led_on(int);
-void led_off(int);
+void led_toggle(uint32_t);
+void led_on(uint32_t);
+void led_off(uint32_t);
+void led_blink_once(uint32_t);
+void blink_once (uint32_t);
 
 #endif	/* ACTUATORS_H */
 
diff --git a/src/libruntime/target/linux/deserializer.c b/src/libruntime/target/linux/deserializer.c
index fb09c43b4..eaa50a2ce 100644
--- a/src/libruntime/target/linux/deserializer.c
+++ b/src/libruntime/target/linux/deserializer.c
@@ -22,11 +22,18 @@ uint8_t num_size = 0;
 const ecma_char_t *
 deserialize_string_by_id (uint8_t id)
 {
-  uint8_t size = *bytecode_data, *data = bytecode_data, offset;
+  uint8_t size, *data, offset;
+
+  if (bytecode_data == NULL)
+    return NULL;
+  
+  size = *bytecode_data;
 
   if (id >= size)
     return NULL;
 
+  data = bytecode_data;
+
   data += id + 1;
 
   offset = *data;
diff --git a/src/main.c b/src/main.c
index ea8ae9e4d..4fc3c6b52 100644
--- a/src/main.c
+++ b/src/main.c
@@ -27,9 +27,9 @@
 #define LED_ORANGE     13
 #define LED_RED        14
 #define LED_BLUE       15
+#include "generated.h"
 #endif
 
-#include "generated.h"
 #include "globals.h"
 #include "interpreter.h"
 #include "jerry-libc.h"
@@ -164,7 +164,7 @@ void fake_exit(void);
 void
 fake_exit (void)
 {
-  uint32_t pin = LED_RED;
+  uint32_t pin = LED_ORANGE;
   uint32_t mode = (uint32_t)GPIO_Mode_OUT << (pin * 2);
   uint32_t speed = (uint32_t)GPIO_Speed_100MHz << (pin * 2);
   uint32_t type = (uint32_t)GPIO_OType_PP << pin;
@@ -185,7 +185,7 @@ fake_exit (void)
   //
   //  Toggle the selected LED indefinitely.
   //
-  int index;
+  volatile int index;
   
   // SOS
   
@@ -213,6 +213,9 @@ fake_exit (void)
 int
 main(void)
 {
+  
+  //fake_exit();
+  
   const char *source_p = generated_source;
   const size_t source_size = sizeof(generated_source);
 
diff --git a/tests/unit/test_addition_opcode_number_operands.c b/tests/unit/test_addition_opcode_number_operands.c
index 1c840fde1..683432222 100644
--- a/tests/unit/test_addition_opcode_number_operands.c
+++ b/tests/unit/test_addition_opcode_number_operands.c
@@ -26,6 +26,7 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
+    getop_reg_var_decl( 255, 255),
     getop_var_decl( 0),
     getop_var_decl( 1),
     getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
diff --git a/tests/unit/test_assignment_opcode.c b/tests/unit/test_assignment_opcode.c
index 8b4ef8292..d138cf377 100644
--- a/tests/unit/test_assignment_opcode.c
+++ b/tests/unit/test_assignment_opcode.c
@@ -26,17 +26,18 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
-    /*  0: */ getop_var_decl( 0),
-    /*  1: */ getop_var_decl( 1),
-    /*  2: */ getop_assignment( 0, OPCODE_ARG_TYPE_STRING, 1),
-    /*  3: */ getop_assignment( 1, OPCODE_ARG_TYPE_VARIABLE, 0),
-    /*  4: */ getop_is_true_jmp( 1, 6),
-    /*  5: */ getop_jmp_down( 5),
-    /*  6: */ getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
-    /*  7: */ getop_assignment( 1, OPCODE_ARG_TYPE_NUMBER, 2),
-    /*  8: */ getop_is_false_jmp( 1, 10),
-    /*  9: */ getop_exitval( 0),
-    /* 10: */ getop_exitval( 1)
+    /*  0: */ getop_reg_var_decl( 255, 255),
+    /*  1: */ getop_var_decl( 0),
+    /*  2: */ getop_var_decl( 1),
+    /*  3: */ getop_assignment( 0, OPCODE_ARG_TYPE_STRING, 1),
+    /*  4: */ getop_assignment( 1, OPCODE_ARG_TYPE_VARIABLE, 0),
+    /*  5: */ getop_is_true_jmp( 1, 7),
+    /*  6: */ getop_jmp_down( 5),
+    /*  7: */ getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
+    /*  8: */ getop_assignment( 1, OPCODE_ARG_TYPE_NUMBER, 2),
+    /*  9: */ getop_is_false_jmp( 1, 11),
+    /* 10: */ getop_exitval( 0),
+    /* 11: */ getop_exitval( 1)
   };
 
   mem_init();
diff --git a/tests/unit/test_division_opcode.c b/tests/unit/test_division_opcode.c
index e14084bbc..5c1c121ac 100644
--- a/tests/unit/test_division_opcode.c
+++ b/tests/unit/test_division_opcode.c
@@ -26,6 +26,7 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
+    getop_reg_var_decl( 255, 255),
     getop_var_decl( 0),
     getop_var_decl( 1),
     getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
diff --git a/tests/unit/test_multiplication_opcode.c b/tests/unit/test_multiplication_opcode.c
index 1bbd2bb29..aba7f5660 100644
--- a/tests/unit/test_multiplication_opcode.c
+++ b/tests/unit/test_multiplication_opcode.c
@@ -26,6 +26,7 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
+    getop_reg_var_decl( 255, 255),
     getop_var_decl( 0),
     getop_var_decl( 1),
     getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
diff --git a/tests/unit/test_remainder_opcode.c b/tests/unit/test_remainder_opcode.c
index a4b7328ce..7e4882a5d 100644
--- a/tests/unit/test_remainder_opcode.c
+++ b/tests/unit/test_remainder_opcode.c
@@ -26,6 +26,7 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
+    getop_reg_var_decl( 255, 255),
     getop_var_decl( 0),
     getop_var_decl( 1),
     getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
diff --git a/tests/unit/test_substraction_opcode.c b/tests/unit/test_substraction_opcode.c
index f8c8d64ab..392f1bfb5 100644
--- a/tests/unit/test_substraction_opcode.c
+++ b/tests/unit/test_substraction_opcode.c
@@ -26,6 +26,7 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
+    getop_reg_var_decl( 255, 255),
     getop_var_decl( 0),
     getop_var_decl( 1),
     getop_assignment( 0, OPCODE_ARG_TYPE_SMALLINT, 253),
diff --git a/tests/unit/test_var_decl_opcode_in_decl_lex_env.c b/tests/unit/test_var_decl_opcode_in_decl_lex_env.c
index d6164c131..a10ab2939 100644
--- a/tests/unit/test_var_decl_opcode_in_decl_lex_env.c
+++ b/tests/unit/test_var_decl_opcode_in_decl_lex_env.c
@@ -26,10 +26,11 @@ main( int __unused argc,
       char __unused **argv)
 {
   const OPCODE test_program[] = {
-    getop_var_decl( 0),
-    getop_is_true_jmp( 0, 3),
-    getop_exitval( 0),
-    getop_exitval( 1)
+    /*  0: */ getop_reg_var_decl( 255, 255),
+    /*  1: */ getop_var_decl( 0),
+    /*  2: */ getop_is_true_jmp( 0, 4),
+    /*  3: */ getop_exitval( 0),
+    /*  4: */ getop_exitval( 1)
   };
 
   mem_init();