diff --git a/Makefile b/Makefile
index 375c7c02f..b0732af98 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,9 @@ OBJ_DIR = obj
 
 SOURCES = \
 	$(sort \
-	$(wildcard ./src/*.c))
+	$(wildcard ./src/*.c)\
+	$(wildcard ./src/libperipherals/*.c)\
+	$(wildcard ./src/libcoreint/*.c))
 
 INCLUDES = \
 	-I src \
@@ -48,7 +50,7 @@ CFLAGS ?= $(INCLUDES) -std=c99 -m32 -fdiagnostics-color=always
 #CFLAGS += -ffunction-sections -fdata-sections
 
 DEBUG_OPTIONS = -g3 -O0 -DDEBUG #-fsanitize=address 
-RELEASE_OPTIONS = -Os -Werror
+RELEASE_OPTIONS = -Os # -Werror
 
 DEFINES = -DMEM_HEAP_CHUNK_SIZE=256 -DMEM_HEAP_AREA_SIZE=32768
 
diff --git a/src/generated.h b/src/generated.h
index 75a92745a..fcd3b82d5 100644
--- a/src/generated.h
+++ b/src/generated.h
@@ -14,41 +14,16 @@
  */
 
 static const char* generated_source = ""
-"// AST\n"
-"// ECMA has no way of including files. Do we need such feature?\n"
-"// EG: Not in initial version\n"
-"require (leds);\n"
-"\n"
-"function LEDsOn () {\n"
-"LEDOn (LED3);\n"
-"LEDOn (LED6);\n"
-"LEDOn (LED7);\n"
-"LEDOn (LED4);\n"
-"LEDOn (LED10);\n"
-"LEDOn (LED8);\n"
-"LEDOn (LED9);\n"
-"LEDOn (LED5);\n"
-"}\n"
-"\n"
-"function LEDsOff () {\n"
-"LEDOff (LED3);\n"
-"LEDOff (LED6);\n"
-"LEDOff (LED7);\n"
-"LEDOff (LED4);\n"
-"LEDOff (LED10);\n"
-"LEDOff (LED8);\n"
-"LEDOff (LED9);\n"
-"LEDOff (LED5);\n"
-"}\n"
-"\n"
-"/*\n"
-"IMHO we don't need this function in our code,\n"
-"we may perform lazy LEDs initialization.\n"
-"*/\n"
-"// initLEDs ();\n"
-"\n"
 "while (true) {\n"
-"setTimeout (LEDsOn, 500);\n"
-"setTimeout (LEDsOff, 500);\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"
 ;
diff --git a/src/lexer.c b/src/lexer.c
index 31a05df90..2f7dd4df5 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -116,55 +116,55 @@ get_char (int i)
   assert (file);
 
   if (buffer == NULL)
+  {
+    buffer = (char *) malloc (BUFFER_SIZE);
+    error = fread (buffer, 1, BUFFER_SIZE, file);
+    if (error < 0)
+      fatal (ERR_IO);
+    if (error == 0)
+      return '\0';
+    if (error < BUFFER_SIZE)
+      memset (buffer + error, '\0', BUFFER_SIZE - error);
+    buffer_start = buffer;
+  }
+
+  if (tail_size <= i)
+  {
+    /* We are almost at the end of the buffer.  */
+    if (token_start)
     {
-      buffer = (char *) malloc (BUFFER_SIZE);
-      error = fread (buffer, 1, BUFFER_SIZE, file);
+      const int token_size = buffer - token_start;
+      /* Whole buffer contains single token.  */
+      if (token_start == buffer_start)
+        fatal (ERR_BUFFER_SIZE);
+      /* Move parsed token and tail of buffer to head.  */
+      memmove (buffer_start, token_start, tail_size + token_size);
+      /* Adjust pointers.  */
+      token_start = buffer_start;
+      buffer = buffer_start + token_size;
+      /* Read more characters form input file.  */
+      error = fread (buffer + tail_size, 1, BUFFER_SIZE - tail_size - token_size, file);
       if (error < 0)
         fatal (ERR_IO);
       if (error == 0)
         return '\0';
-      if (error < BUFFER_SIZE)
-        memset (buffer + error, '\0', BUFFER_SIZE - error);
-      buffer_start = buffer;
+      if (error < BUFFER_SIZE - tail_size - token_size)
+        memset (buffer + tail_size + error, '\0',
+                BUFFER_SIZE - tail_size - token_size - error);
     }
-
-  if (tail_size <= i)
+    else
     {
-    /* We are almost at the end of the buffer.  */
-      if (token_start)
-        {
-          const int token_size = buffer - token_start;
-          /* Whole buffer contains single token.  */
-          if (token_start == buffer_start)
-            fatal (ERR_BUFFER_SIZE);
-          /* Move parsed token and tail of buffer to head.  */
-          memmove (buffer_start, token_start, tail_size + token_size);
-          /* Adjust pointers.  */
-          token_start = buffer_start;
-          buffer = buffer_start + token_size;
-          /* Read more characters form input file.  */
-          error = fread (buffer + tail_size, 1, BUFFER_SIZE - tail_size - token_size, file);
-          if (error < 0)
-            fatal (ERR_IO);
-          if (error == 0)
-            return '\0';
-          if (error < BUFFER_SIZE - tail_size - token_size)
-            memset (buffer + tail_size + error, '\0',
-                    BUFFER_SIZE - tail_size - token_size - error);
-        }
-      else
-        {
-          memmove (buffer_start, buffer, tail_size);
-          buffer = buffer_start;
-          error = fread (buffer + tail_size, 1, BUFFER_SIZE - tail_size, file);
-          if (error < 0)
-            fatal (ERR_IO);
-          if (error == 0)
-            return '\0';
-          if (error < BUFFER_SIZE - tail_size)
-            memset (buffer + tail_size + error, '\0', BUFFER_SIZE - tail_size - error);
-        }
+      memmove (buffer_start, buffer, tail_size);
+      buffer = buffer_start;
+      error = fread (buffer + tail_size, 1, BUFFER_SIZE - tail_size, file);
+      if (error < 0)
+        fatal (ERR_IO);
+      if (error == 0)
+        return '\0';
+      if (error < BUFFER_SIZE - tail_size)
+        memset (buffer + tail_size + error, '\0', BUFFER_SIZE - tail_size - error);
     }
+  }
 
   return *(buffer + i);
 }
@@ -245,55 +245,74 @@ parse_name ()
   new_token ();
   consume_char ();
   while (true)
-    {
-      c = LA (0);
-      if (c == '\0')
-        c = c;
-      if (!isalpha (c) && !isdigit (c) && c != '$' && c != '_')
-        break;
-      if (every_char_islower && (!isalpha (c) || !islower (c)))
-        every_char_islower = false;
-      consume_char ();
-    }
+  {
+    c = LA (0);
+    if (c == '\0')
+      c = c;
+    if (!isalpha (c) && !isdigit (c) && c != '$' && c != '_')
+      break;
+    if (every_char_islower && (!isalpha (c) || !islower (c)))
+      every_char_islower = false;
+    consume_char ();
+  }
 
   tok = current_token ();
   if (every_char_islower)
+  {
+    keyword kw = decode_keyword (tok);
+    if (kw != KW_NONE)
     {
-      keyword kw = decode_keyword (tok);
-      if (kw != KW_NONE)
-        {
-          free ((char *) tok);
-          return (token) { .type = TOK_KEYWORD, .data.kw = kw };
-        }
+      free ((char *) tok);
 
-      if (!strcmp ("null", tok))
-        {
-          free ((char *) tok);
-          return (token) { .type = TOK_NULL, .data.none = NULL };
-        }
-
-      if (!strcmp ("true", tok))
-        {
-          free ((char *) tok);
-          return (token) { .type = TOK_BOOL, .data.is_true = true };
-        }
-
-      if (!strcmp ("false", tok))
-        {
-          free ((char *) tok);
-          return (token) { .type = TOK_BOOL, .data.is_true = false };
-        }
+      return (token)
+      {
+        .type = TOK_KEYWORD, .data.kw = kw
+      };
     }
 
-  return (token) { .type = TOK_NAME, .data.name = tok };
+    if (!strcmp ("null", tok))
+    {
+      free ((char *) tok);
+
+      return (token)
+      {
+        .type = TOK_NULL, .data.none = NULL
+      };
+    }
+
+    if (!strcmp ("true", tok))
+    {
+      free ((char *) tok);
+
+      return (token)
+      {
+        .type = TOK_BOOL, .data.is_true = true
+      };
+    }
+
+    if (!strcmp ("false", tok))
+    {
+      free ((char *) tok);
+
+      return (token)
+      {
+        .type = TOK_BOOL, .data.is_true = false
+      };
+    }
+  }
+
+  return (token)
+  {
+    .type = TOK_NAME, .data.name = tok
+  };
 }
 
 static bool
 is_hex_digit (char c)
 {
   return isdigit (c) || c == 'a' || c == 'A' || c == 'b' || c == 'B'
-                     || c == 'c' || c == 'C' || c == 'd' || c == 'D'
-                     || c == 'e' || c == 'E' || c == 'f' || c == 'F';
+          || c == 'c' || c == 'C' || c == 'd' || c == 'D'
+          || c == 'e' || c == 'E' || c == 'f' || c == 'F';
 }
 
 static int
@@ -301,29 +320,29 @@ hex_to_int (char hex)
 {
   switch (hex)
   {
-    case '0': return 0x0;
-    case '1': return 0x1;
-    case '2': return 0x2;
-    case '3': return 0x3;
-    case '4': return 0x4;
-    case '5': return 0x5;
-    case '6': return 0x6;
-    case '7': return 0x7;
-    case '8': return 0x8;
-    case '9': return 0x9;
-    case 'a': 
-    case 'A': return 0xA;
-    case 'b': 
-    case 'B': return 0xB;
-    case 'c': 
-    case 'C': return 0xC;
-    case 'd': 
-    case 'D': return 0xD;
-    case 'e': 
-    case 'E': return 0xE;
-    case 'f': 
-    case 'F': return 0xF;
-    default: unreachable ();
+  case '0': return 0x0;
+  case '1': return 0x1;
+  case '2': return 0x2;
+  case '3': return 0x3;
+  case '4': return 0x4;
+  case '5': return 0x5;
+  case '6': return 0x6;
+  case '7': return 0x7;
+  case '8': return 0x8;
+  case '9': return 0x9;
+  case 'a':
+  case 'A': return 0xA;
+  case 'b':
+  case 'B': return 0xB;
+  case 'c':
+  case 'C': return 0xC;
+  case 'd':
+  case 'D': return 0xD;
+  case 'e':
+  case 'E': return 0xE;
+  case 'f':
+  case 'F': return 0xF;
+  default: unreachable ();
   }
 }
 
@@ -347,38 +366,42 @@ parse_number ()
       is_hex = true;
 
   if (c == '.')
-    {
-      assert (!isalpha (LA (1)));
-      is_fp = true;
-    }
+  {
+    assert (!isalpha (LA (1)));
+    is_fp = true;
+  }
 
   if (is_hex)
+  {
+    // Eat up '0x'
+    consume_char ();
+    consume_char ();
+    new_token ();
+    while (true)
     {
-      // Eat up '0x'
+      c = LA (0);
+      if (!is_hex_digit (c))
+        break;
       consume_char ();
-      consume_char ();
-      new_token ();
-      while (true)
-        {
-          c = LA (0);
-          if (!is_hex_digit (c))
-            break;
-          consume_char ();
-        }
-
-      if (isalpha (c) || c == '_' || c == '$')
-        fatal (ERR_INT_LITERAL);
-
-      tok_length = buffer - token_start;
-      tok = current_token ();
-      // OK, I know that integer overflow can occur here
-      for (int i = 0; i < tok_length; i++)
-        res = (res << 4) + hex_to_int (tok[i]);
-
-      free ((char *) tok);
-      return (token) { .type = TOK_INT, .data.num = res };
     }
 
+    if (isalpha (c) || c == '_' || c == '$')
+      fatal (ERR_INT_LITERAL);
+
+    tok_length = buffer - token_start;
+    tok = current_token ();
+    // OK, I know that integer overflow can occur here
+    for (int i = 0; i < tok_length; i++)
+      res = (res << 4) + hex_to_int (tok[i]);
+
+    free ((char *) tok);
+
+    return (token)
+    {
+      .type = TOK_INT, .data.num = res
+    };
+  }
+
   assert (!is_hex && !is_exp);
 
   new_token ();
@@ -388,49 +411,53 @@ parse_number ()
     consume_char ();
 
   while (true)
+  {
+    c = LA (0);
+    if (is_fp && c == '.')
+      fatal (ERR_INT_LITERAL);
+    if (is_exp && (c == 'e' || c == 'E'))
+      fatal (ERR_INT_LITERAL);
+
+    if (c == '.')
     {
-      c = LA (0);
-      if (is_fp && c == '.')
+      if (isalpha (LA (1)) || LA (1) == '_' || LA (1) == '$')
         fatal (ERR_INT_LITERAL);
-      if (is_exp && (c == 'e' || c == 'E'))
-        fatal (ERR_INT_LITERAL);
-
-      if (c == '.')
-        {
-          if (isalpha (LA (1)) || LA (1) == '_' || LA (1) == '$')
-            fatal (ERR_INT_LITERAL);
-          is_fp = true;
-          consume_char ();
-          continue;
-        }
-
-      if (c == 'e' || c == 'E')
-        {
-          if (LA (1) == '-' || LA (1) == '+')
-            consume_char ();
-          if (!isdigit (LA (1)))
-            fatal (ERR_INT_LITERAL);
-          is_exp = true;
-          consume_char ();
-          continue;
-        }
-
-      if (isalpha (c) || c == '_' || c == '$')
-        fatal (ERR_INT_LITERAL);
-
-      if (!isdigit (c))
-        break;
-
+      is_fp = true;
       consume_char ();
+      continue;
     }
 
+    if (c == 'e' || c == 'E')
+    {
+      if (LA (1) == '-' || LA (1) == '+')
+        consume_char ();
+      if (!isdigit (LA (1)))
+        fatal (ERR_INT_LITERAL);
+      is_exp = true;
+      consume_char ();
+      continue;
+    }
+
+    if (isalpha (c) || c == '_' || c == '$')
+      fatal (ERR_INT_LITERAL);
+
+    if (!isdigit (c))
+      break;
+
+    consume_char ();
+  }
+
   if (is_fp || is_exp)
+  {
+    tok = current_token ();
+    float res = strtof (tok, NULL);
+    free ((char *) tok);
+
+    return (token)
     {
-      tok = current_token ();
-      float res = strtof (tok, NULL);
-      free ((char *) tok);
-      return (token) { .type = TOK_FLOAT, .data.fp_num = res };
-    }
+      .type = TOK_FLOAT, .data.fp_num = res
+    };
+  }
 
   tok_length = buffer - token_start;
   tok = current_token ();
@@ -439,7 +466,11 @@ parse_number ()
     res = res * 10 + hex_to_int (tok[i]);
 
   free ((char *) tok);
-  return (token) { .type = TOK_INT, .data.num = res };
+
+  return (token)
+  {
+    .type = TOK_INT, .data.num = res
+  };
 }
 
 static char
@@ -447,16 +478,16 @@ escape_char (char c)
 {
   switch (c)
   {
-    case 'b': return '\b';
-    case 'f': return '\f';
-    case 'n': return '\n';
-    case 'r': return '\r';
-    case 't': return '\t';
-    case 'v': return '\v';
-    case '\'':
-    case '"':
-    case '\\':
-    default: return c;
+  case 'b': return '\b';
+  case 'f': return '\f';
+  case 'n': return '\n';
+  case 'r': return '\r';
+  case 't': return '\t';
+  case 'v': return '\v';
+  case '\'':
+  case '"':
+  case '\\':
+  default: return c;
   }
 }
 
@@ -478,63 +509,66 @@ parse_string ()
   new_token ();
 
   while (true)
+  {
+    c = LA (0);
+    if (c == '\0')
+      fatal (ERR_UNCLOSED);
+    if (c == '\n')
+      fatal (ERR_STRING);
+    if (c == '\\')
     {
-      c = LA (0);
-      if (c == '\0')
-        fatal (ERR_UNCLOSED);
-      if (c == '\n')
+      /* Only single escape character is allowed.  */
+      if (LA (1) == 'x' || LA (1) == 'u' || isdigit (LA (1)))
         fatal (ERR_STRING);
-      if (c == '\\')
-        {
-          /* Only single escape character is allowed.  */
-          if (LA (1) == 'x' || LA (1) == 'u' || isdigit (LA (1)))
-            fatal (ERR_STRING);
-          if ((LA (1) == '\'' && !is_double_quoted)
-              || (LA (1) == '"' && is_double_quoted)
-              || LA (1) == '\n')
-            {
-              consume_char ();
-              consume_char ();
-              continue;
-            }
-        }
-      else if ((c == '\'' && !is_double_quoted)
-          || (c == '"' && is_double_quoted))
-        break;
-
-      consume_char ();
+      if ((LA (1) == '\'' && !is_double_quoted)
+          || (LA (1) == '"' && is_double_quoted)
+          || LA (1) == '\n')
+      {
+        consume_char ();
+        consume_char ();
+        continue;
+      }
     }
+    else if ((c == '\'' && !is_double_quoted)
+             || (c == '"' && is_double_quoted))
+      break;
+
+    consume_char ();
+  }
 
   length = buffer - token_start;
   tok = (char *) malloc (length);
   index = tok;
 
   for (char *i = token_start; i < buffer; i++)
+  {
+    if (*i == '\\')
     {
-      if (*i == '\\')
-        {
-          if (*(i+1) == '\n')
-            {
-              i++;
-              continue;
-            }
-          *index = escape_char (*(i+1));
-          index++;
-          i++;
-          continue;
-        }
-
-      *index = *i;
+      if (*(i + 1) == '\n')
+      {
+        i++;
+        continue;
+      }
+      *index = escape_char (*(i + 1));
       index++;
+      i++;
+      continue;
     }
 
+    *index = *i;
+    index++;
+  }
+
   memset (index, '\0', length - (index - tok));
 
   token_start = NULL;
   // Eat up '"'
   consume_char ();
 
-  return (token) { .type = TOK_STRING, .data.str = tok };
+  return (token)
+  {
+    .type = TOK_STRING, .data.str = tok
+  };
 }
 
 static void
@@ -543,10 +577,10 @@ grobble_whitespaces ()
   char c = LA (0);
 
   while ((isspace (c) && c != '\n') || c == '\0')
-    {
-      consume_char ();
-      c = LA (0);
-    }
+  {
+    consume_char ();
+    c = LA (0);
+  }
 }
 
 void
@@ -554,7 +588,9 @@ lexer_set_file (FILE *ex_file)
 {
   assert (ex_file);
   file = ex_file;
+#ifdef DEBUG
   lexer_debug_log = fopen ("lexer.log", "w");
+#endif
 }
 
 static bool
@@ -573,25 +609,25 @@ replace_comment_by_newline ()
   consume_char ();
 
   while (true)
+  {
+    c = LA (0);
+    if (!multiline && (c == '\n' || c == '\0'))
+      return false;
+    if (multiline && c == '*' && LA (1) == '/')
     {
-      c = LA (0);
-      if (!multiline && (c == '\n' || c == '\0'))
-        return false;
-      if (multiline && c == '*' && LA (1) == '/')
-        {
-          consume_char ();
-          consume_char ();
-          if (was_newlines)
-            return true;
-          else
-            return false;
-        }
-      if (multiline && c == '\n')
-        was_newlines = true;
-      if (multiline && c == '\0')
-        fatal (ERR_UNCLOSED);
       consume_char ();
+      consume_char ();
+      if (was_newlines)
+        return true;
+      else
+        return false;
     }
+    if (multiline && c == '\n')
+      was_newlines = true;
+    if (multiline && c == '\0')
+      fatal (ERR_UNCLOSED);
+    consume_char ();
+  }
 }
 
 token
@@ -604,11 +640,11 @@ lexer_next_token ()
   char c = LA (0);
 
   if (saved_token.type != TOK_EOF)
-    {
-      token res = saved_token;
-      saved_token.type = TOK_EOF;
-      return res;
-    }
+  {
+    token res = saved_token;
+    saved_token.type = TOK_EOF;
+    return res;
+  }
 
   assert (token_start == NULL);
 
@@ -619,98 +655,108 @@ lexer_next_token ()
     return parse_number ();
 
   if (c == '\n')
+  {
+    consume_char ();
+
+    return (token)
     {
-      consume_char ();
-      return (token) { .type = TOK_NEWLINE, .data.none = NULL };
-    }
+      .type = TOK_NEWLINE, .data.none = NULL
+    };
+  }
 
   if (c == '\0')
-    return (token) { .type = TOK_EOF, .data.none = NULL };
+    return (token)
+  {
+    .type = TOK_EOF, .data.none = NULL
+  };
 
   if (c == '\'' || c == '"')
     return parse_string ();
 
   if (isspace (c))
-    {
-      grobble_whitespaces ();
-      return lexer_next_token ();
-    }
+  {
+    grobble_whitespaces ();
+    return lexer_next_token ();
+  }
 
   if (c == '/' && LA (1) == '*')
+  {
+    if (replace_comment_by_newline ())
+      return (token)
     {
-      if (replace_comment_by_newline ())
-        return (token) { .type = TOK_NEWLINE, .data.none = NULL };
-      else
-        return lexer_next_token ();
-    }
+      .type = TOK_NEWLINE, .data.none = NULL
+    };
+    else
+      return lexer_next_token ();
+  }
 
   if (c == '/' && LA (1) == '/')
-    {
-      replace_comment_by_newline ();
-      return lexer_next_token ();
-    }
+  {
+    replace_comment_by_newline ();
+    return lexer_next_token ();
+  }
 
   switch (c)
   {
-    case '{': RETURN_PUNC (TOK_OPEN_BRACE);
-    case '}': RETURN_PUNC (TOK_CLOSE_BRACE);
-    case '(': RETURN_PUNC (TOK_OPEN_PAREN);
-    case ')': RETURN_PUNC (TOK_CLOSE_PAREN);
-    case '[': RETURN_PUNC (TOK_OPEN_SQUARE);
-    case ']': RETURN_PUNC (TOK_CLOSE_SQUARE);
-    case '.': RETURN_PUNC (TOK_DOT);
-    case ';': RETURN_PUNC (TOK_SEMICOLON);
-    case ',': RETURN_PUNC (TOK_COMMA);
-    case '~': RETURN_PUNC (TOK_COMPL);
-    case ':': RETURN_PUNC (TOK_COLON);
-    case '?': RETURN_PUNC (TOK_QUERY);
+  case '{': RETURN_PUNC (TOK_OPEN_BRACE);
+  case '}': RETURN_PUNC (TOK_CLOSE_BRACE);
+  case '(': RETURN_PUNC (TOK_OPEN_PAREN);
+  case ')': RETURN_PUNC (TOK_CLOSE_PAREN);
+  case '[': RETURN_PUNC (TOK_OPEN_SQUARE);
+  case ']': RETURN_PUNC (TOK_CLOSE_SQUARE);
+  case '.': RETURN_PUNC (TOK_DOT);
+  case ';': RETURN_PUNC (TOK_SEMICOLON);
+  case ',': RETURN_PUNC (TOK_COMMA);
+  case '~': RETURN_PUNC (TOK_COMPL);
+  case ':': RETURN_PUNC (TOK_COLON);
+  case '?': RETURN_PUNC (TOK_QUERY);
 
-    case '*': IF_LA_IS ('=', TOK_MULT_EQ, TOK_MULT);
-    case '/': IF_LA_IS ('=', TOK_DIV_EQ, TOK_DIV);
-    case '^': IF_LA_IS ('=', TOK_XOR_EQ, TOK_XOR);
-    case '%': IF_LA_IS ('=', TOK_MOD_EQ, TOK_MOD);
+  case '*': IF_LA_IS ('=', TOK_MULT_EQ, TOK_MULT);
+  case '/': IF_LA_IS ('=', TOK_DIV_EQ, TOK_DIV);
+  case '^': IF_LA_IS ('=', TOK_XOR_EQ, TOK_XOR);
+  case '%': IF_LA_IS ('=', TOK_MOD_EQ, TOK_MOD);
 
-    case '+': IF_LA_IS_OR ('+', TOK_DOUBLE_PLUS, '=', TOK_PLUS_EQ, TOK_PLUS);
-    case '-': IF_LA_IS_OR ('-', TOK_DOUBLE_MINUS, '=', TOK_MINUS_EQ, TOK_MINUS);
-    case '&': IF_LA_IS_OR ('&', TOK_DOUBLE_AND, '=', TOK_AND_EQ, TOK_AND);
-    case '|': IF_LA_IS_OR ('|', TOK_DOUBLE_OR, '=', TOK_OR_EQ, TOK_OR);
+  case '+': IF_LA_IS_OR ('+', TOK_DOUBLE_PLUS, '=', TOK_PLUS_EQ, TOK_PLUS);
+  case '-': IF_LA_IS_OR ('-', TOK_DOUBLE_MINUS, '=', TOK_MINUS_EQ, TOK_MINUS);
+  case '&': IF_LA_IS_OR ('&', TOK_DOUBLE_AND, '=', TOK_AND_EQ, TOK_AND);
+  case '|': IF_LA_IS_OR ('|', TOK_DOUBLE_OR, '=', TOK_OR_EQ, TOK_OR);
 
-    case '<': 
-      switch (LA (1))
-      {
-        case '<': IF_LA_N_IS ('=', TOK_LSHIFT_EQ, TOK_LSHIFT, 2);
-        case '=': RETURN_PUNC_EX (TOK_LESS_EQ, 2);
-        default: RETURN_PUNC (TOK_LESS);
-      }
+  case '<':
+    switch (LA (1))
+    {
+    case '<': IF_LA_N_IS ('=', TOK_LSHIFT_EQ, TOK_LSHIFT, 2);
+    case '=': RETURN_PUNC_EX (TOK_LESS_EQ, 2);
+    default: RETURN_PUNC (TOK_LESS);
+    }
 
+  case '>':
+    switch (LA (1))
+    {
     case '>':
-      switch (LA (1))
+      switch (LA (2))
       {
-        case '>':
-          switch (LA (2))
-          {
-            case '>': IF_LA_N_IS ('=', TOK_RSHIFT_EX_EQ, TOK_RSHIFT_EX, 3);
-            case '=': RETURN_PUNC_EX (TOK_RSHIFT_EQ, 3);
-            default: RETURN_PUNC_EX (TOK_RSHIFT, 2);
-          }
-        case '=': RETURN_PUNC_EX (TOK_GREATER_EQ, 2);
-        default: RETURN_PUNC (TOK_GREATER);
+      case '>': IF_LA_N_IS ('=', TOK_RSHIFT_EX_EQ, TOK_RSHIFT_EX, 3);
+      case '=': RETURN_PUNC_EX (TOK_RSHIFT_EQ, 3);
+      default: RETURN_PUNC_EX (TOK_RSHIFT, 2);
       }
+    case '=': RETURN_PUNC_EX (TOK_GREATER_EQ, 2);
+    default: RETURN_PUNC (TOK_GREATER);
+    }
 
-    case '=':
-      if (LA (1) == '=')
-        IF_LA_N_IS ('=', TOK_TRIPLE_EQ, TOK_DOUBLE_EQ, 2);
-      else
-        RETURN_PUNC (TOK_EQ);
+  case '=':
+    if (LA (1) == '=')
+      IF_LA_N_IS ('=', TOK_TRIPLE_EQ, TOK_DOUBLE_EQ, 2);
+    else
+      RETURN_PUNC (TOK_EQ);
 
-    case '!':
-      if (LA (1) == '=')
-        IF_LA_N_IS ('=', TOK_NOT_DOUBLE_EQ, TOK_NOT_EQ, 2);
-      else
-        RETURN_PUNC (TOK_NOT);
+  case '!':
+    if (LA (1) == '=')
+      IF_LA_N_IS ('=', TOK_NOT_DOUBLE_EQ, TOK_NOT_EQ, 2);
+    else
+      RETURN_PUNC (TOK_NOT);
 
-    default:
-      unreachable ();
+  default:
+    unreachable ();
   }
   fatal (ERR_NON_CHAR);
 }
@@ -725,11 +771,11 @@ lexer_next_token ()
   if (tok.type == TOK_NEWLINE)
     return tok;
   if (tok.type == TOK_CLOSE_BRACE)
-    {
-      if (i == 300)
-        fprintf (lexer_debug_log, "lexer_next_token(%d): type=0x%x, data=%p\n", i, tok.type, tok.data.none);
-      i++;
-    }
+  {
+    if (i == 300)
+      fprintf (lexer_debug_log, "lexer_next_token(%d): type=0x%x, data=%p\n", i, tok.type, tok.data.none);
+    i++;
+  }
   return tok;
 }
 #endif
@@ -737,10 +783,10 @@ lexer_next_token ()
 void
 lexer_save_token (token tok)
 {
-  #ifdef DEBUG
+#ifdef DEBUG
   if (tok.type == TOK_CLOSE_BRACE)
     fprintf (lexer_debug_log, "lexer_save_token(%d): type=0x%x, data=%p\n", i, tok.type, tok.data.none);
-  #endif
+#endif
   saved_token = tok;
 }
 
diff --git a/src/libcoreint/interpreter.c b/src/libcoreint/interpreter.c
new file mode 100644
index 000000000..18320c462
--- /dev/null
+++ b/src/libcoreint/interpreter.c
@@ -0,0 +1,87 @@
+/* Copyright 2014 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "error.h"
+#include "lexer.h"
+#include "parser.h"
+#include "pretty-printer.h"
+#include "interpreter.h"
+#include "opcode.h"
+
+
+void
+safe_opcode (FILE *file, opcode_ptr ptr, int arg1, int arg2)
+{
+  curr_opcode.func = ptr;
+  curr_opcode.arg1 = arg1;
+  curr_opcode.arg2 = arg2;
+
+  if (file != NULL)
+  {
+    fwrite (&curr_opcode, sizeof (struct opcode_packed), 1, file);
+  }
+}
+
+void
+gen_bytecode (FILE *src_file)
+{
+  statement *st;
+  lexer_set_file (src_file);
+  parser_init ();
+  st = parser_parse_statement ();
+  assert (st);
+  while (st->type != STMT_EOF)
+  {
+    pp_statement (st);
+    st = parser_parse_statement ();
+    assert (st);
+  }
+  pp_finish ();
+
+  FILE *file = fopen (FILE_NAME, "w+b");
+  int i;
+
+  for (i = 0; i <= 10; i++)
+  {
+    safe_opcode (file, control_op, i, i);
+    safe_opcode (file, decl_op, i, i);
+    safe_opcode (file, call_op, i, i);
+  }
+
+  fclose (file);
+}
+
+void
+run_int ()
+{
+  FILE *file = fopen (FILE_NAME, "rb");
+
+  if (file == NULL)
+  {
+    fputs ("File error", stderr);
+    exit (1);
+  }
+
+  while (!feof (file))
+  {
+    fread (&curr_opcode, sizeof (struct opcode_packed), 1, file);
+
+    //printf ("read %d, %d, %p\n", curr_opcode.arg1, curr_opcode.arg2, curr_opcode.func);
+    curr_opcode.func (curr_opcode.arg1, curr_opcode.arg2);
+  }
+
+  fclose (file);
+}
+
diff --git a/src/libcoreint/interpreter.h b/src/libcoreint/interpreter.h
new file mode 100644
index 000000000..a2f172913
--- /dev/null
+++ b/src/libcoreint/interpreter.h
@@ -0,0 +1,39 @@
+/* Copyright 2014 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* 
+ * File:   interpreter.h
+ * Author: egavrin
+ *
+ * Created on July 2, 2014, 3:10 PM
+ */
+
+#ifndef INTERPRETER_H
+#define	INTERPRETER_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "opcode.h"
+
+#define FILE_NAME "application.bin"
+
+void safe_opcode(FILE *, opcode_ptr, int, int);
+void gen_bytecode(FILE*);
+void run_int();
+
+#endif	/* INTERPRETER_H */
+
diff --git a/src/libcoreint/opcode.c b/src/libcoreint/opcode.c
new file mode 100644
index 000000000..7a05f325d
--- /dev/null
+++ b/src/libcoreint/opcode.c
@@ -0,0 +1,33 @@
+/* Copyright 2014 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "opcode.h"
+
+#include <stdio.h>
+
+OP_DEFINITION (control_op)
+{
+  printf ("control_op %d, %d\n", arg1, arg2);
+}
+
+OP_DEFINITION (decl_op)
+{
+  printf ("decl_op %d, %d\n", arg1, arg2);
+}
+
+OP_DEFINITION (call_op)
+{
+  printf ("call_op %d, %d\n", arg1, arg2);
+}
\ No newline at end of file
diff --git a/src/libcoreint/opcode.h b/src/libcoreint/opcode.h
new file mode 100644
index 000000000..3571f0db4
--- /dev/null
+++ b/src/libcoreint/opcode.h
@@ -0,0 +1,55 @@
+/* Copyright 2014 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* 
+ * File:   opcode.h
+ * Author: egavrin
+ *
+ * Created on July 2, 2014, 3:12 PM
+ */
+
+#ifndef OPCODE_H
+#define	OPCODE_H
+
+#define OP_RET_TYPE void
+#define OP_ARG_TYPE int
+
+#define OP_ATTR_DECL OP_ARG_TYPE, OP_ARG_TYPE
+#define OP_ATTR_DEF OP_ARG_TYPE arg1, OP_ARG_TYPE arg2
+
+#define OP_DECLARATION(opname) OP_RET_TYPE opname (OP_ATTR_DECL)
+#define OP_DEFINITION(opname) OP_RET_TYPE opname (OP_ATTR_DEF)
+
+// opcode ptr
+typedef OP_RET_TYPE (*opcode_ptr)(OP_ATTR_DECL);
+
+struct
+__attribute__ ((__packed__))
+opcode_packed
+{
+  opcode_ptr func;
+  OP_ARG_TYPE arg1;
+  OP_ARG_TYPE arg2;
+}
+curr_opcode;
+
+#define INIT_OPCODE_PTR(func) opcode_ptr func_ptr = ptr;
+
+OP_DECLARATION (decl_op);
+OP_DECLARATION (call_op);
+OP_DECLARATION (control_op);
+
+#endif	/* OPCODE_H */
+
diff --git a/src/main.c b/src/main.c
index a88a0d491..0c0ba42e0 100644
--- a/src/main.c
+++ b/src/main.c
@@ -18,13 +18,22 @@
 #include <string.h>
 
 #include "error.h"
-#include "lexer.h"
-#include "parser.h"
-#include "pretty-printer.h"
 
 #include "ctx-manager.h"
 #include "mem-allocator.h"
 
+#include "interpreter.h"
+
+#include "generated.h"
+
+void fake_exit ();
+
+void
+fake_exit (void)
+{
+  for (;;);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -58,36 +67,17 @@ main (int argc, char **argv)
   file = fopen (file_name, "r");
 
   if (file == NULL)
+  {
     fatal (ERR_IO);
-
-  if (dump_tokens)
-  {
-    token tok;
-    lexer_set_file (file);
-    tok = lexer_next_token ();
-    pp_reset ();
-    while (tok.type != TOK_EOF)
-    {
-      pp_token (tok);
-      tok = lexer_next_token ();
-    }
   }
 
-  if (dump_ast)
-  {
-    statement *st;
-    lexer_set_file (file);
-    parser_init ();
-    st = parser_parse_statement ();
-    assert (st);
-    while (st->type != STMT_EOF)
-    {
-      pp_statement (st);
-      st = parser_parse_statement ();
-      assert (st);
-    }
-    pp_finish ();
-  }
+  //gen_bytecode (generated_source);
+  gen_bytecode (file);
+  run_int ();
+
+#ifdef __TARGET_MCU
+  fake_exit ();
+#endif 
 
   return 0;
 }
diff --git a/tests/jerry-tests/blinky-min.js b/tests/jerry-tests/blinky-min.js
new file mode 100644
index 000000000..eb39f9943
--- /dev/null
+++ b/tests/jerry-tests/blinky-min.js
@@ -0,0 +1,26 @@
+// Copyright 2014 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.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+while (true) {
+    LEDToggle (LED3);
+    LEDToggle (LED6);
+    LEDToggle (LED7);
+    LEDToggle (LED4);
+    LEDToggle (LED10);
+    LEDToggle (LED8);
+    LEDToggle (LED9);
+    LEDToggle (LED5);
+
+    wait(500);
+}
diff --git a/tools/generator.sh b/tools/generator.sh
new file mode 100755
index 000000000..b8af8754f
--- /dev/null
+++ b/tools/generator.sh
@@ -0,0 +1,22 @@
+# Copyright 2014 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.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#!/bin/bash
+
+echo "static const char* generated_source = \"\"" > "generated.h"
+while read line
+do
+  echo "\"$line\n\"" >> "generated.h"
+done < $1
+echo ";" >> "generated.h"
\ No newline at end of file