[Debugger] Implementation of transport over serial connection (#2800)

JerryScript-DCO-1.0-Signed-off-by: Robert Sipka rsipka.uszeged@partner.samsung.com

docs/07.DEBUGGER.md

@@ -68,9 +68,11 @@ When using the extension-provided WebSocket transport layer, the
 debugger can be enabled by calling `jerryx_debugger_after_connect
 (jerryx_debugger_tcp_create (debug_port) && jerryx_debugger_ws_create ())`
 after the `jerry_init ()` function. It initializes the debugger and
-blocks until a client connects. (Custom transport layers may be
-implemented and initialized similarly. Currently, `jerryx_debugger_rp_create()` for
-raw packet transport layer is also available.)
+blocks until a client connects.
+(Custom transport layers may be implemented and initialized similarly.
+Currently, `jerryx_debugger_rp_create ()` for raw packet transport layer and
+`jerryx_debugger_serial_create (const char* config)` for serial protocol
+are also available.)
 
 The resource name provided to `jerry_parse ()` is used by the client
 to identify the resource name of the source code. This resource name

jerry-core/api/jerry.c

@@ -193,6 +193,8 @@ jerry_cleanup (void)
 #ifdef JERRY_DEBUGGER
   if (JERRY_CONTEXT (debugger_flags) & JERRY_DEBUGGER_CONNECTED)
   {
+    jerry_debugger_send_type (JERRY_DEBUGGER_CLOSE_CONNECTION);
+
     jerry_debugger_transport_close ();
   }
 #endif /* JERRY_DEBUGGER */

jerry-core/debugger/debugger.c

@@ -38,9 +38,9 @@ typedef struct
  * The number of message types in the debugger should reflect the
  * debugger versioning.
  */
-JERRY_STATIC_ASSERT (JERRY_DEBUGGER_MESSAGES_OUT_MAX_COUNT == 32
+JERRY_STATIC_ASSERT (JERRY_DEBUGGER_MESSAGES_OUT_MAX_COUNT == 33
                      && JERRY_DEBUGGER_MESSAGES_IN_MAX_COUNT == 21
-                     && JERRY_DEBUGGER_VERSION == 8,
+                     && JERRY_DEBUGGER_VERSION == 9,
                      debugger_version_correlates_to_message_type_count);
 
 /**

jerry-core/debugger/debugger.h

@@ -156,6 +156,7 @@ typedef enum
   JERRY_DEBUGGER_SCOPE_CHAIN_END = 29, /**< last output of scope chain */
   JERRY_DEBUGGER_SCOPE_VARIABLES = 30, /**< scope variables */
   JERRY_DEBUGGER_SCOPE_VARIABLES_END = 31, /**< last output of scope variables */
+  JERRY_DEBUGGER_CLOSE_CONNECTION = 32, /**< close connection with the client */
   JERRY_DEBUGGER_MESSAGES_OUT_MAX_COUNT, /**< number of different type of output messages by the debugger */
 
   /* Messages sent by the client to server. */

jerry-core/include/jerryscript-debugger.h

@@ -31,7 +31,7 @@ extern "C"
 /**
  * JerryScript debugger protocol version.
  */
-#define JERRY_DEBUGGER_VERSION (8)
+#define JERRY_DEBUGGER_VERSION (9)
 
 /**
  * Types for the client source wait and run method.

jerry-debugger/jerry_client.py

@@ -24,6 +24,11 @@ import logging
 import time
 import jerry_client_main
 
+from jerry_client_websocket import WebSocket
+from jerry_client_rawpacket import RawPacket
+from jerry_client_tcp import Socket
+from jerry_client_serial import Serial
+
 def write(string):
     print(string, end='')
 
@@ -246,14 +251,40 @@ def src_check_args(args):
         print("Error: Non-negative integer number expected: %s" % (val_errno))
         return -1
 
-# pylint: disable=too-many-branches,too-many-locals,too-many-statements
+# pylint: disable=too-many-branches,too-many-locals,too-many-statements,redefined-variable-type
 def main():
     args = jerry_client_main.arguments_parse()
 
-    debugger = jerry_client_main.JerryDebugger(args.address, args.channel)
+    channel = None
+    protocol = None
+
+    if args.protocol == "tcp":
+        address = None
+        if ":" not in args.address:
+            address = (args.address, 5001) # use default port
+        else:
+            host, port = args.address.split(":")
+            address = (host, int(port))
+
+        protocol = Socket(address)
+    elif args.protocol == "serial":
+        protocol = Serial(args.serial_config)
+    else:
+        print("Unsupported transmission protocol")
+        return -1
+
+    if args.channel == "websocket":
+        channel = WebSocket(protocol=protocol)
+    elif args.channel == "rawpacket":
+        channel = RawPacket(protocol=protocol)
+    else:
+        print("Unsupported communication channel")
+        return -1
+
+    debugger = jerry_client_main.JerryDebugger(channel)
     debugger.non_interactive = args.non_interactive
 
-    logging.debug("Connected to JerryScript on %d port", debugger.port)
+    logging.debug("Connected to JerryScript")
 
     prompt = DebuggerPrompt(debugger)
     prompt.prompt = "(jerry-debugger) "

jerry-debugger/jerry_client_main.py

@@ -21,12 +21,9 @@ import re
 import select
 import struct
 import sys
-from jerry_client_websocket import WebSocket
-from jerry_client_rawpacket import RawPacket
-from jerry_client_tcp import Socket
 
 # Expected debugger protocol version.
-JERRY_DEBUGGER_VERSION = 8
+JERRY_DEBUGGER_VERSION = 9
 
 # Messages sent by the server to client.
 JERRY_DEBUGGER_CONFIGURATION = 1
@@ -60,6 +57,7 @@ JERRY_DEBUGGER_SCOPE_CHAIN = 28
 JERRY_DEBUGGER_SCOPE_CHAIN_END = 29
 JERRY_DEBUGGER_SCOPE_VARIABLES = 30
 JERRY_DEBUGGER_SCOPE_VARIABLES_END = 31
+JERRY_DEBUGGER_CLOSE_CONNECTION = 32
 
 # Debugger option flags
 JERRY_DEBUGGER_LITTLE_ENDIAN = 0x1
@@ -123,7 +121,7 @@ def arguments_parse():
     parser = argparse.ArgumentParser(description="JerryScript debugger client")
 
     parser.add_argument("address", action="store", nargs="?", default="localhost:5001",
-                        help="specify a unique network address for connection (default: %(default)s)")
+                        help="specify a unique network address for tcp connection (default: %(default)s)")
     parser.add_argument("-v", "--verbose", action="store_true", default=False,
                         help="increase verbosity (default: %(default)s)")
     parser.add_argument("--non-interactive", action="store_true", default=False,
@@ -138,6 +136,10 @@ def arguments_parse():
                         help="specify a javascript source file to execute")
     parser.add_argument("--channel", choices=["websocket", "rawpacket"], default="websocket",
                         help="specify the communication channel (default: %(default)s)")
+    parser.add_argument("--protocol", choices=["tcp", "serial"], default="tcp",
+                        help="specify the transmission protocol over the communication channel (default: %(default)s)")
+    parser.add_argument("--serial-config", metavar="CONFIG_STRING", default="/dev/ttyUSB0,115200,8,N,1",
+                        help="Configure parameters for serial port (default: %(default)s)")
     args = parser.parse_args()
 
     if args.verbose:
@@ -266,17 +268,7 @@ class DebuggerAction(object):
 
 class JerryDebugger(object):
     # pylint: disable=too-many-instance-attributes,too-many-statements,too-many-public-methods,no-self-use,redefined-variable-type
-    def __init__(self, address, channel):
-
-        if ":" not in address:
-            self.host = address
-            self.port = 5001  # use default port
-        else:
-            self.host, self.port = address.split(":")
-            self.port = int(self.port)
-
-        print("Connecting to: %s:%s" % (self.host, self.port))
-
+    def __init__(self, channel):
         self.prompt = False
         self.function_list = {}
         self.source = ''
@@ -304,15 +296,7 @@ class JerryDebugger(object):
         self.non_interactive = False
         self.current_out = b""
         self.current_log = b""
-        self.channel = None
-
-        protocol = Socket()
-        if channel == "websocket":
-            self.channel = WebSocket(address=(self.host, self.port), protocol=protocol)
-        elif channel == "rawpacket":
-            self.channel = RawPacket(address=(self.host, self.port), protocol=protocol)
-        else:
-            raise Exception("Unsupported communication channel")
+        self.channel = channel
 
         config_size = 8
         # The server will send the configuration message after connection established
@@ -697,7 +681,6 @@ class JerryDebugger(object):
     # pylint: disable=too-many-branches,too-many-locals,too-many-statements,too-many-return-statements
     def process_messages(self):
         result = ""
-
         while True:
             data = self.channel.get_message(False)
             if not self.non_interactive:
@@ -846,6 +829,9 @@ class JerryDebugger(object):
 
                 return DebuggerAction(DebuggerAction.TEXT, result)
 
+            elif JERRY_DEBUGGER_CLOSE_CONNECTION:
+                return DebuggerAction(DebuggerAction.END, "")
+
             else:
                 raise Exception("Unknown message")
 

jerry-debugger/jerry_client_rawpacket.py

@@ -20,14 +20,13 @@ MAX_BUFFER_SIZE = 256
 
 class RawPacket(object):
     """ Simplified transmission layer. """
-    def __init__(self, address, protocol):
+    def __init__(self, protocol):
         self.protocol = protocol
         self.data_buffer = b""
-        self.address = address
 
     def connect(self, config_size):
         """  Create connection. """
-        self.protocol.connect(self.address)
+        self.protocol.connect()
         self.data_buffer = b""
 
         # It will return with the Network configurations, which has the following struct:

jerry-debugger/jerry_client_serial.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+# Copyright JS Foundation and other contributors, http://js.foundation
+#
+# 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.
+
+import select
+import serial
+
+class Serial(object):
+    """ Create a new socket using the given address family, socket type and protocol number. """
+    def __init__(self, serial_config):
+        config = serial_config.split(',')
+        config_size = len(config)
+
+        port = config[0] if config_size > 0 else "/dev/ttyUSB0"
+        baudrate = config[1] if config_size > 1 else 115200
+        bytesize = int(config[2]) if config_size > 2 else 8
+        parity = config[3] if config_size > 3 else 'N'
+        stopbits = int(config[4]) if config_size > 4 else 1
+
+        self.ser = serial.Serial(port=port, baudrate=baudrate, parity=parity,
+                                 stopbits=stopbits, bytesize=bytesize, timeout=1)
+
+    def connect(self):
+        """ Connect to the server, write a 'c' to the serial port """
+        self.send_data('c')
+
+    def close(self):
+        """"  close the serial port. """
+        self.ser.close()
+
+    def receive_data(self, max_size=1024):
+        """ The maximum amount of data to be received at once is specified by max_size. """
+        return self.ser.read(max_size)
+
+    def send_data(self, data):
+        """ Write data to the serial port. """
+        return self.ser.write(data)
+
+    def ready(self):
+        """ Monitor the file descriptor. """
+        result = select.select([self.ser.fileno()], [], [], 0)[0]
+
+        return self.ser.fileno() in result

jerry-debugger/jerry_client_tcp.py

@@ -17,17 +17,20 @@
 import socket
 import select
 
+# pylint: disable=too-many-arguments,superfluous-parens
 class Socket(object):
     """ Create a new socket using the given address family, socket type and protocol number. """
-    def __init__(self, socket_family=socket.AF_INET, socket_type=socket.SOCK_STREAM, proto=0, fileno=None):
+    def __init__(self, address, socket_family=socket.AF_INET, socket_type=socket.SOCK_STREAM, proto=0, fileno=None):
+        self.address = address
         self.socket = socket.socket(socket_family, socket_type, proto, fileno)
 
-    def connect(self, address):
+    def connect(self):
         """
         Connect to a remote socket at address (host, port).
         The format of address depends on the address family.
         """
-        self.socket.connect(address)
+        print("Connecting to: %s:%s" % (self.address[0], self.address[1]))
+        self.socket.connect(self.address)
 
     def close(self):
         """" Mark the socket closed. """

jerry-debugger/jerry_client_websocket.py

@@ -21,11 +21,10 @@ WEBSOCKET_BINARY_FRAME = 2
 WEBSOCKET_FIN_BIT = 0x80
 
 class WebSocket(object):
-    def __init__(self, address, protocol):
+    def __init__(self, protocol):
 
         self.data_buffer = b""
         self.protocol = protocol
-        self.address = address
 
     def __handshake(self):
         """ Client Handshake Request. """
@@ -55,7 +54,7 @@ class WebSocket(object):
 
     def connect(self, config_size):
         """  WebSockets connection. """
-        self.protocol.connect(self.address)
+        self.protocol.connect()
         self.data_buffer = b""
         self.__handshake()
 

jerry-ext/debugger/debugger-serial.c

@@ -0,0 +1,409 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * 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 "jerryscript-debugger-transport.h"
+#include "jerryscript-ext/debugger.h"
+#include "jext-common.h"
+
+#if defined JERRY_DEBUGGER && !defined WIN32
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <termios.h>
+#include <stdlib.h>
+
+/* Max size of configuration string */
+#define CONFIG_SIZE (255)
+
+/**
+ * Implementation of transport over serial connection.
+ */
+typedef struct
+{
+  jerry_debugger_transport_header_t header; /**< transport header */
+  int fd; /**< file descriptor */
+} jerryx_debugger_transport_serial_t;
+
+/**
+ * Configure parameters for a serial port.
+ */
+typedef struct
+{
+  char *device_id;
+  uint32_t baud_rate; /**< specify the rate at which bits are transmitted for the serial interface */
+  uint32_t data_bits; /**< specify the number of data bits to transmit over the serial interface */
+  char parity; /**< specify how you want to check parity bits in the data bits transmitted via the serial port */
+  uint32_t stop_bits; /**< specify the number of bits used to indicate the end of a byte. */
+} jerryx_debugger_transport_serial_config_t;
+
+/**
+ * Correctly close a file descriptor.
+ */
+static inline void
+jerryx_debugger_serial_close_fd (int fd) /**< file descriptor to close */
+{
+  if (close (fd) != 0)
+  {
+    JERRYX_ERROR_MSG ("Error while closing the file descriptor: %d\n", errno);
+  }
+} /* jerryx_debugger_serial_close_fd */
+
+/**
+ * Set a file descriptor to blocking or non-blocking mode.
+ *
+ * @return true if everything is ok
+ *         false if there was an error
+ **/
+static bool
+jerryx_debugger_serial_set_blocking (int fd, bool blocking)
+{
+  /* Save the current flags */
+  int flags = fcntl (fd, F_GETFL, 0);
+  if (flags == -1)
+  {
+    JERRYX_ERROR_MSG ("Error %d during get flags from file descriptor\n", errno);
+    return false;
+  }
+
+  if (blocking)
+  {
+    flags &= ~O_NONBLOCK;
+  }
+  else
+  {
+    flags |= O_NONBLOCK;
+  }
+
+  if (fcntl (fd, F_SETFL, flags) == -1)
+  {
+    JERRYX_ERROR_MSG ("Error %d during set flags from file descriptor\n", errno);
+    return false;
+  }
+
+  return true;
+} /* jerryx_debugger_serial_set_blocking */
+
+/**
+ * Configure the file descriptor used by the serial communcation.
+ *
+ * @return true if everything is ok
+ *         false if there was an error
+ */
+static inline bool
+jerryx_debugger_serial_configure_attributes (int fd, jerryx_debugger_transport_serial_config_t serial_config)
+{
+  struct termios options;
+  memset (&options, 0, sizeof (options));
+
+  /* Get the parameters associated with the file descriptor */
+  if (tcgetattr (fd, &options) != 0)
+  {
+    JERRYX_ERROR_MSG ("Error %d from tggetattr\n", errno);
+    return false;
+  }
+
+  /* Set the input and output baud rates */
+  cfsetispeed (&options, serial_config.baud_rate);
+  cfsetospeed (&options, serial_config.baud_rate);
+
+  /* Set the control modes */
+  options.c_cflag &= (uint32_t) ~CSIZE; // character size mask
+  options.c_cflag |= (CLOCAL | CREAD); // ignore modem control lines and enable the receiver
+
+  switch (serial_config.data_bits)
+  {
+    case 5:
+    {
+      options.c_cflag |= CS5; // set character size mask to 5-bit chars
+      break;
+    }
+    case 6:
+    {
+      options.c_cflag |= CS6; // set character size mask to 6-bit chars
+      break;
+    }
+    case 7:
+    {
+      options.c_cflag |= CS7; // set character size mask to 7-bit chars
+      break;
+    }
+    case 8:
+    {
+      options.c_cflag |= CS8; // set character size mask to 8-bit chars
+      break;
+    }
+    default:
+    {
+      JERRYX_ERROR_MSG ("Unsupported data bits: %d\n", serial_config.data_bits);
+      return false;
+    }
+  }
+
+  switch (serial_config.parity)
+  {
+    case 'N':
+    {
+      options.c_cflag &= (unsigned int) ~(PARENB | PARODD);
+      break;
+    }
+    case 'O':
+    {
+      options.c_cflag |= PARENB;
+      options.c_cflag |= PARODD;
+      break;
+    }
+    case 'E':
+    {
+      options.c_cflag |= PARENB;
+      options.c_cflag |= PARODD;
+      break;
+    }
+    default:
+    {
+      JERRYX_ERROR_MSG ("Unsupported parity: %c\n", serial_config.parity);
+      return false;
+    }
+  }
+
+  switch (serial_config.stop_bits)
+  {
+    case 1:
+    {
+      options.c_cflag &= (uint32_t) ~CSTOPB; // set 1 stop bits
+      break;
+    }
+    case 2:
+    {
+      options.c_cflag |= CSTOPB; // set 2 stop bits
+      break;
+    }
+    default:
+    {
+      JERRYX_ERROR_MSG ("Unsupported stop bits: %d\n", serial_config.stop_bits);
+      return false;
+    }
+  }
+
+  /* Set the input modes */
+  options.c_iflag &= (uint32_t) ~IGNBRK; // disable break processing
+  options.c_iflag &= (uint32_t) ~(IXON | IXOFF | IXANY); // disable xon/xoff ctrl
+
+  /* Set the output modes: no remapping, no delays */
+  options.c_oflag = 0;
+
+  /* Set the local modes: no signaling chars, no echo, no canoncial processing */
+  options.c_lflag = 0;
+
+  /* Read returns when at least one byte of data is available. */
+  options.c_cc[VMIN]  = 1; // read block
+  options.c_cc[VTIME] = 5; // 0.5 seconds read timeout
+
+  /* Set the parameters associated with the file descriptor */
+  if (tcsetattr (fd, TCSANOW, &options) != 0)
+  {
+    JERRYX_ERROR_MSG ("Error %d from tcsetattr", errno);
+    return false;
+  }
+
+  /* Flushes both data received but not read, and data written but not transmitted */
+  if (tcflush (fd, TCIOFLUSH) != 0)
+  {
+    JERRYX_ERROR_MSG ("Error %d in tcflush() :%s\n", errno, strerror (errno));
+    jerryx_debugger_serial_close_fd (fd);
+    return false;
+  }
+
+  return true;
+} /* jerryx_debugger_serial_configure_attributes */
+
+/**
+ * Close a serial connection.
+ */
+static void
+jerryx_debugger_serial_close (jerry_debugger_transport_header_t *header_p) /**< serial implementation */
+{
+  JERRYX_ASSERT (!jerry_debugger_transport_is_connected ());
+
+  jerryx_debugger_transport_serial_t *serial_p = (jerryx_debugger_transport_serial_t *) header_p;
+
+  JERRYX_DEBUG_MSG ("Serial connection closed.\n");
+
+  jerryx_debugger_serial_close_fd (serial_p->fd);
+
+  jerry_heap_free ((void *) header_p, sizeof (jerryx_debugger_transport_serial_t));
+} /* jerryx_debugger_serial_close */
+
+/**
+ * Send data over a serial connection.
+ *
+ * @return true - if the data has been sent successfully
+ *         false - otherwise
+ */
+static bool
+jerryx_debugger_serial_send (jerry_debugger_transport_header_t *header_p, /**< serial implementation */
+                             uint8_t *message_p, /**< message to be sent */
+                             size_t message_length) /**< message length in bytes */
+{
+  JERRYX_ASSERT (jerry_debugger_transport_is_connected ());
+
+  jerryx_debugger_transport_serial_t *serial_p = (jerryx_debugger_transport_serial_t *) header_p;
+
+  do
+  {
+    ssize_t sent_bytes = write (serial_p->fd, message_p, message_length);
+
+    if (sent_bytes < 0)
+    {
+      if (errno == EWOULDBLOCK)
+      {
+        continue;
+      }
+
+      JERRYX_ERROR_MSG ("Error: write to file descriptor: %d\n", errno);
+      jerry_debugger_transport_close ();
+      return false;
+    }
+
+    message_p += sent_bytes;
+    message_length -= (size_t) sent_bytes;
+  }
+  while (message_length > 0);
+
+  return true;
+} /* jerryx_debugger_serial_send */
+
+/**
+ * Receive data from a serial connection.
+ */
+static bool
+jerryx_debugger_serial_receive (jerry_debugger_transport_header_t *header_p, /**< serial implementation */
+                                jerry_debugger_transport_receive_context_t *receive_context_p) /**< receive context */
+{
+  jerryx_debugger_transport_serial_t *serial_p = (jerryx_debugger_transport_serial_t *) header_p;
+
+  uint8_t *buffer_p = receive_context_p->buffer_p + receive_context_p->received_length;
+  size_t buffer_size = JERRY_DEBUGGER_TRANSPORT_MAX_BUFFER_SIZE - receive_context_p->received_length;
+
+  ssize_t length = read (serial_p->fd, buffer_p, buffer_size);
+
+  if (length <= 0)
+  {
+    if (errno != EWOULDBLOCK || length == 0)
+    {
+      jerry_debugger_transport_close ();
+      return false;
+    }
+    length = 0;
+  }
+
+  receive_context_p->received_length += (size_t) length;
+
+  if (receive_context_p->received_length > 0)
+  {
+    receive_context_p->message_p = receive_context_p->buffer_p;
+    receive_context_p->message_length = receive_context_p->received_length;
+  }
+
+  return true;
+} /* jerryx_debugger_serial_receive */
+
+/**
+ * Create a serial connection.
+ *
+ * @return true if successful,
+ *         false otherwise
+ */
+bool
+jerryx_debugger_serial_create (const char *config) /**< specify the configuration */
+{
+  /* Parse the configuration string */
+  char tmp_config[CONFIG_SIZE];
+  strncpy (tmp_config, config, CONFIG_SIZE);
+  jerryx_debugger_transport_serial_config_t serial_config;
+
+  char *token = strtok (tmp_config, ",");
+  serial_config.device_id = token ? token : "/dev/ttyS0";
+  serial_config.baud_rate = (token = strtok (NULL, ",")) ? (uint32_t) strtoul (token, NULL, 10) : 115200;
+  serial_config.data_bits = (token = strtok (NULL, ",")) ? (uint32_t) strtoul (token, NULL, 10) : 8;
+  serial_config.parity = (token = strtok (NULL, ",")) ? token[0] : 'N';
+  serial_config.stop_bits = (token = strtok (NULL, ",")) ? (uint32_t) strtoul (token, NULL, 10) : 1;
+
+  int fd = open (serial_config.device_id, O_RDWR);
+
+  if (fd < 0)
+  {
+    JERRYX_ERROR_MSG ("Error %d opening %s: %s", errno, serial_config.device_id, strerror (errno));
+    return false;
+  }
+
+  if (!jerryx_debugger_serial_configure_attributes (fd, serial_config))
+  {
+    jerryx_debugger_serial_close_fd (fd);
+    return false;
+  }
+
+  JERRYX_DEBUG_MSG ("Waiting for client connection\n");
+
+  /* Client will sent a 'c' char to initiate the connection. */
+  uint8_t conn_char;
+  ssize_t t = read (fd, &conn_char, 1);
+  if (t != 1 || conn_char != 'c' || !jerryx_debugger_serial_set_blocking (fd, false))
+  {
+    return false;
+  }
+
+  JERRYX_DEBUG_MSG ("Client connected\n");
+
+  size_t size = sizeof (jerryx_debugger_transport_serial_t);
+
+  jerry_debugger_transport_header_t *header_p;
+  header_p = (jerry_debugger_transport_header_t *) jerry_heap_alloc (size);
+
+  if (!header_p)
+  {
+    jerryx_debugger_serial_close_fd (fd);
+    return false;
+  }
+
+  header_p->close = jerryx_debugger_serial_close;
+  header_p->send = jerryx_debugger_serial_send;
+  header_p->receive = jerryx_debugger_serial_receive;
+
+  ((jerryx_debugger_transport_serial_t *) header_p)->fd = fd;
+
+  jerry_debugger_transport_add (header_p,
+                                0,
+                                JERRY_DEBUGGER_TRANSPORT_MAX_BUFFER_SIZE,
+                                0,
+                                JERRY_DEBUGGER_TRANSPORT_MAX_BUFFER_SIZE);
+
+  return true;
+} /* jerryx_debugger_serial_create */
+
+#else /* !JERRY_DEBUGGER || WIN32 */
+/**
+ * Dummy function when debugger is disabled.
+ *
+ * @return false
+ */
+bool
+jerryx_debugger_serial_create (const char *config)
+{
+  JERRYX_UNUSED (config);
+  return false;
+} /* jerryx_debugger_serial_create */
+
+#endif /* JERRY_DEBUGGER */

jerry-ext/include/jerryscript-ext/debugger.h

@@ -30,6 +30,7 @@ void jerryx_debugger_after_connect (bool success);
  * Message transmission interfaces.
  */
 bool jerryx_debugger_tcp_create (uint16_t port);
+bool jerryx_debugger_serial_create (const char *config);
 
 /*
  * Message encoding interfaces.

jerry-main/main-unix.c

@@ -318,6 +318,8 @@ typedef enum
   OPT_DEBUG_SERVER,
   OPT_DEBUG_PORT,
   OPT_DEBUG_CHANNEL,
+  OPT_DEBUG_PROTOCOL,
+  OPT_DEBUG_SERIAL_CONFIG,
   OPT_DEBUGGER_WAIT_SOURCE,
   OPT_EXEC_SNAP,
   OPT_EXEC_SNAP_FUNC,
@@ -349,6 +351,10 @@ static const cli_opt_t main_opts[] =
                .help = "debug server port (default: 5001)"),
   CLI_OPT_DEF (.id = OPT_DEBUG_CHANNEL, .longopt = "debug-channel", .meta = "[websocket|rawpacket]",
                .help = "Specify the debugger transmission channel (default: websocket)"),
+  CLI_OPT_DEF (.id = OPT_DEBUG_PROTOCOL, .longopt = "debug-protocol", .meta = "PROTOCOL",
+               .help = "Specify the transmission protocol over the communication channel (tcp|serial, default: tcp)"),
+  CLI_OPT_DEF (.id = OPT_DEBUG_SERIAL_CONFIG, .longopt = "serial-config", .meta = "OPTIONS_STRING",
+               .help = "Configure parameters for serial port (default: /dev/ttyS0,115200,8,N,1)"),
   CLI_OPT_DEF (.id = OPT_DEBUGGER_WAIT_SOURCE, .longopt = "debugger-wait-source",
                .help = "wait for an executable source from the client"),
   CLI_OPT_DEF (.id = OPT_EXEC_SNAP, .longopt = "exec-snapshot", .meta = "FILE",
@@ -422,21 +428,33 @@ context_alloc (size_t size,
 static void
 init_engine (jerry_init_flag_t flags, /**< initialized flags for the engine */
              char *debug_channel, /**< enable the debugger init or not */
-             uint16_t debug_port) /**< the debugger port */
+             char *debug_protocol, /**< enable the debugger init or not */
+             uint16_t debug_port, /**< the debugger port for tcp protocol */
+             char *debug_serial_config) /**< configuration string for serial protocol */
 {
   jerry_init (flags);
   if (strcmp (debug_channel, ""))
   {
-    bool tcp_created = jerryx_debugger_tcp_create (debug_port);
+    bool protocol = false;
+
+    if (!strcmp (debug_protocol, "tcp"))
+    {
+      protocol = jerryx_debugger_tcp_create (debug_port);
+    }
+    else
+    {
+      assert (!strcmp (debug_protocol, "serial"));
+      protocol = jerryx_debugger_serial_create (debug_serial_config);
+    }
 
     if (!strcmp (debug_channel, "rawpacket"))
     {
-      jerryx_debugger_after_connect (tcp_created && jerryx_debugger_rp_create ());
+      jerryx_debugger_after_connect (protocol && jerryx_debugger_rp_create ());
     }
     else
     {
       assert (!strcmp (debug_channel, "websocket"));
-      jerryx_debugger_after_connect (tcp_created && jerryx_debugger_ws_create ());
+      jerryx_debugger_after_connect (protocol && jerryx_debugger_ws_create ());
     }
   }
 
@@ -464,6 +482,8 @@ main (int argc,
   bool start_debug_server = false;
   uint16_t debug_port = 5001;
   char *debug_channel = "websocket";
+  char *debug_protocol = "tcp";
+  char *debug_serial_config = "/dev/ttyS0,115200,8,N,1";
 
   bool is_repl_mode = false;
   bool is_wait_mode = false;
@@ -542,6 +562,24 @@ main (int argc,
         }
         break;
       }
+      case OPT_DEBUG_PROTOCOL:
+      {
+        if (check_feature (JERRY_FEATURE_DEBUGGER, cli_state.arg))
+        {
+          debug_protocol = (char *) cli_consume_string (&cli_state);
+          check_usage (!strcmp (debug_protocol, "tcp") || !strcmp (debug_protocol, "serial"),
+                       argv[0], "Error: invalid value for --debug-protocol: ", cli_state.arg);
+        }
+        break;
+      }
+      case OPT_DEBUG_SERIAL_CONFIG:
+      {
+        if (check_feature (JERRY_FEATURE_DEBUGGER, cli_state.arg))
+        {
+          debug_serial_config = (char *) cli_consume_string (&cli_state);
+        }
+        break;
+      }
       case OPT_DEBUGGER_WAIT_SOURCE:
       {
         if (check_feature (JERRY_FEATURE_DEBUGGER, cli_state.arg))
@@ -640,7 +678,7 @@ main (int argc,
     debug_channel = "";
   }
 
-  init_engine (flags, debug_channel, debug_port);
+  init_engine (flags, debug_channel, debug_protocol, debug_port, debug_serial_config);
 
   jerry_value_t ret_value = jerry_create_undefined ();
 
@@ -758,7 +796,7 @@ main (int argc,
             break;
           }
 
-          init_engine (flags, debug_channel, debug_port);
+          init_engine (flags, debug_channel, debug_protocol, debug_port, debug_serial_config);
 
           ret_value = jerry_create_undefined ();
         }
@@ -802,7 +840,7 @@ main (int argc,
 
     jerry_cleanup ();
 
-    init_engine (flags, debug_channel, debug_port);
+    init_engine (flags, debug_channel, debug_protocol, debug_port, debug_serial_config);
 
     ret_value = jerry_create_undefined ();
   }