enable easier cross-compilation

15 files changed, 1408 insertions, 0 deletions

diff --git a/flow/src/main/java/com/github/jodersky/flow/internal/NativeSerial.java b/flow/src/main/java/com/github/jodersky/flow/internal/NativeSerial.java
new file mode 100644
index 0000000..524803e
--- /dev/null
+++ b/flow/src/main/java/com/github/jodersky/flow/internal/NativeSerial.java
@@ -0,0 +1,75 @@
+package com.github.jodersky.flow.internal;
+
+import com.github.jodersky.flow.internal.NativeLoader;
+
+/** Thin layer on top of native code. */
+class NativeSerial {
+	
+	static {
+		NativeLoader.load();
+	}
+	
+	final static int E_IO = -1;
+	final static int E_ACCESS_DENIED = -2;
+	final static int E_BUSY = -3;
+	final static int E_INVALID_SETTINGS = -4;
+	final static int E_INTERRUPT = -5;
+	final static int E_NO_PORT = -6;
+	
+	final static int PARITY_NONE = 0;
+	final static int PARITY_ODD = 1;
+	final static int PARITY_EVEN = 2;
+
+	/**Opens a serial port and allocates memory for storing configuration. Note: if this function fails,
+	 * any internally allocated resources will be freed.
+	 * @param device name of port
+	 * @param baud baud rate
+	 * @param characterSize character size of data transmitted through serial device
+	 * @param twoStopBits set to use two stop bits instead of one
+	 * @param parity kind of parity checking to use
+	 * @param serial pointer to memory that will be allocated with a serial structure
+	 * @return 0 on success
+	 * @return E_NO_PORT if the given port does not exist
+	 * @return E_ACCESS_DENIED if permissions are not sufficient to open port
+	 * @return E_BUSY if port is already in use
+	 * @return E_INVALID_SETTINGS if any of the specified settings are not supported
+	 * @return E_IO on other error */
+	native static int open(String device, int baud, int characterSize, boolean twoStopBits, int parity, long[] serial);
+	
+	/**Starts a blocking read from a previously opened serial port. The read is blocking, however it may be
+	 * interrupted by calling 'serial_interrupt' on the given serial port.
+	 * @param serial pointer to serial configuration from which to read
+	 * @param buffer buffer into which data is read
+	 * @param size maximum buffer size
+	 * @return n>0 the number of bytes read into buffer
+	 * @return E_INTERRUPT if the call to this function was interrupted
+	 * @return E_IO on IO error */
+	native static int read(long serial, byte[] buffer);
+	
+	/**Writes data to a previously opened serial port.
+	 * @param serial pointer to serial configuration to which to write
+	 * @param data data to write
+	 * @param size number of bytes to write from data
+	 * @return n>0 the number of bytes written
+	 * @return E_IO on IO error */
+	native static int write(long serial, byte[] buffer);
+	
+	/**Interrupts a blocked read call.
+	 * @param serial_config the serial port to interrupt
+	 * @return 0 on success
+	 * @return E_IO on error */
+	native static int interrupt(long serial);
+	
+	/**Closes a previously opened serial port and frees memory containing the configuration. Note: after a call to
+	 * this function, the 'serial' pointer will become invalid, make sure you only call it once. This function is NOT
+	 * thread safe, make sure no read or write is in prgress when this function is called (the reason is that per 
+	 * close manual page, close should not be called on a file descriptor that is in use by another thread). 
+	 * @param serial pointer to serial configuration that is to be closed (and freed)
+	 * @return 0 on success
+	 * @return E_IO on error */
+	native static int close(long serial);
+	
+	/**Sets debugging option. If debugging is enabled, detailed error message are printed (to stderr) from method calls. */
+	native static void debug(boolean value);
+
+}
diff --git a/flow/src/main/native/include/com_github_jodersky_flow_internal_NativeSerial.h b/flow/src/main/native/include/com_github_jodersky_flow_internal_NativeSerial.h
new file mode 100644
index 0000000..1c71688
--- /dev/null
+++ b/flow/src/main/native/include/com_github_jodersky_flow_internal_NativeSerial.h
@@ -0,0 +1,79 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class com_github_jodersky_flow_internal_NativeSerial */
+
+#ifndef _Included_com_github_jodersky_flow_internal_NativeSerial
+#define _Included_com_github_jodersky_flow_internal_NativeSerial
+#ifdef __cplusplus
+extern "C" {
+#endif
+#undef com_github_jodersky_flow_internal_NativeSerial_E_IO
+#define com_github_jodersky_flow_internal_NativeSerial_E_IO -1L
+#undef com_github_jodersky_flow_internal_NativeSerial_E_ACCESS_DENIED
+#define com_github_jodersky_flow_internal_NativeSerial_E_ACCESS_DENIED -2L
+#undef com_github_jodersky_flow_internal_NativeSerial_E_BUSY
+#define com_github_jodersky_flow_internal_NativeSerial_E_BUSY -3L
+#undef com_github_jodersky_flow_internal_NativeSerial_E_INVALID_SETTINGS
+#define com_github_jodersky_flow_internal_NativeSerial_E_INVALID_SETTINGS -4L
+#undef com_github_jodersky_flow_internal_NativeSerial_E_INTERRUPT
+#define com_github_jodersky_flow_internal_NativeSerial_E_INTERRUPT -5L
+#undef com_github_jodersky_flow_internal_NativeSerial_E_NO_PORT
+#define com_github_jodersky_flow_internal_NativeSerial_E_NO_PORT -6L
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_NONE
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_NONE 0L
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_ODD
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_ODD 1L
+#undef com_github_jodersky_flow_internal_NativeSerial_PARITY_EVEN
+#define com_github_jodersky_flow_internal_NativeSerial_PARITY_EVEN 2L
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    open
+ * Signature: (Ljava/lang/String;IIZI[J)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_open
+  (JNIEnv *, jclass, jstring, jint, jint, jboolean, jint, jlongArray);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    read
+ * Signature: (J[B)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_read
+  (JNIEnv *, jclass, jlong, jbyteArray);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    write
+ * Signature: (J[B)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_write
+  (JNIEnv *, jclass, jlong, jbyteArray);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    interrupt
+ * Signature: (J)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_interrupt
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    close
+ * Signature: (J)I
+ */
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_close
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     com_github_jodersky_flow_internal_NativeSerial
+ * Method:    debug
+ * Signature: (Z)V
+ */
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_debug
+  (JNIEnv *, jclass, jboolean);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/flow/src/main/native/include/flow.h b/flow/src/main/native/include/flow.h
new file mode 100644
index 0000000..ebb845a
--- /dev/null
+++ b/flow/src/main/native/include/flow.h
@@ -0,0 +1,80 @@
+#ifndef FLOW_H
+#define FLOW_H
+
+#include <stdbool.h>
+
+//general error codes that are returned by functions
+#define E_IO -1 //I/O error (port should be closed)
+#define E_ACCESS_DENIED -2 //access denied
+#define E_BUSY -3 // port is busy
+#define E_INVALID_SETTINGS -4 // some port settings are invalid
+#define E_INTERRUPT -5 // not really an error, function call aborted because port is closed
+#define E_NO_PORT -6 //requested port does not exist
+
+#define PARITY_NONE 0
+#define PARITY_ODD 1
+#define PARITY_EVEN 2
+
+/** Represents an open serial port. */
+struct serial_config;
+
+/**Opens a serial port and allocates memory for storing configuration. Note: if this function fails,
+ * any internally allocated resources will be freed.
+ * @param port_name name of port
+ * @param baud baud rate
+ * @param char_size character size of data transmitted through serial device
+ * @param two_stop_bits set to use two stop bits instead of one
+ * @param parity kind of parity checking to use
+ * @param serial pointer to memory that will be allocated with a serial structure
+ * @return 0 on success
+ * @return E_NO_PORT if the given port does not exist
+ * @return E_ACCESS_DENIED if permissions are not sufficient to open port
+ * @return E_BUSY if port is already in use
+ * @return E_INVALID_SETTINGS if any of the specified settings are not supported
+ * @return E_IO on other error */
+int serial_open(
+  const char* port_name,
+  int baud,
+  int char_size,
+  bool two_stop_bits,
+  int parity,
+  struct serial_config** serial);
+
+/**Closes a previously opened serial port and frees memory containing the configuration. Note: after a call to
+ * this function, the 'serial' pointer will become invalid, make sure you only call it once. This function is NOT
+ * thread safe, make sure no read or write is in prgress when this function is called (the reason is that per 
+ * close manual page, close should not be called on a file descriptor that is in use by another thread). 
+ * @param serial pointer to serial configuration that is to be closed (and freed)
+ * @return 0 on success
+ * @return E_IO on error */
+int serial_close(struct serial_config* serial);
+
+/**Starts a read from a previously opened serial port. The read is blocking, however it may be
+ * interrupted by calling 'serial_interrupt' on the given serial port.
+ * @param serial pointer to serial configuration from which to read
+ * @param buffer buffer into which data is read
+ * @param size maximum buffer size
+ * @return n>0 the number of bytes read into buffer
+ * @return E_INTERRUPT if the call to this function was interrupted
+ * @return E_IO on IO error */
+int serial_read(struct serial_config* serial, unsigned char* buffer, size_t size);
+
+/**Interrupts a blocked read call.
+ * @param serial_config the serial port to interrupt
+ * @return 0 on success
+ * @return E_IO on error */
+int serial_interrupt(struct serial_config* serial);
+
+/**Writes data to a previously opened serial port. Non bocking.
+ * @param serial pointer to serial configuration to which to write
+ * @param data data to write
+ * @param size number of bytes to write from data
+ * @return n>0 the number of bytes written
+ * @return E_IO on IO error */
+int serial_write(struct serial_config* serial, unsigned char* data, size_t size);
+
+/**Sets debugging option. If debugging is enabled, detailed error message are printed from method calls. */
+void serial_debug(bool value);
+
+
+#endif /* FLOW_H */
diff --git a/flow/src/main/native/posix/flow.c b/flow/src/main/native/posix/flow.c
new file mode 100644
index 0000000..caf7b9b
--- /dev/null
+++ b/flow/src/main/native/posix/flow.c
@@ -0,0 +1,312 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <termios.h>
+#include <fcntl.h>
+#include "com_github_jodersky_flow_internal_NativeSerial.h"
+#include "flow.h"
+
+static bool debug = false;
+#define DEBUG(f) if (debug) {f}
+
+void serial_debug(bool value) {
+  debug = value;
+}
+
+//contains file descriptors used in managing a serial port
+struct serial_config {
+  
+  int port_fd; // file descriptor of serial port
+  
+  /* a pipe is used to abort a serial read by writing something into the
+   * write end of the pipe */
+  int pipe_read_fd; // file descriptor, read end of pipe
+  int pipe_write_fd; // file descriptor, write end of pipe
+  
+};
+
+int serial_open(
+  const char* port_name,
+  int baud,
+  int char_size,
+  bool two_stop_bits,
+  int parity,
+  struct serial_config** serial) {
+  
+  int fd = open(port_name, O_RDWR | O_NOCTTY | O_NONBLOCK);
+  
+  if (fd < 0) {
+    int en = errno;
+    DEBUG(perror("obtain file descriptor"););
+    if (en == EACCES) return E_ACCESS_DENIED;
+    if (en == ENOENT) return E_NO_PORT;
+    return E_IO;
+  }
+  
+  if (flock(fd, LOCK_EX | LOCK_NB) < 0) {
+    DEBUG(perror("acquire lock on port"););
+    close(fd);
+    return E_BUSY;
+  }
+  
+  /* configure new port settings */
+  struct termios newtio;
+  
+  /* following calls correspond to makeraw() */
+  newtio.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+  newtio.c_oflag &= ~OPOST;
+  newtio.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+  newtio.c_cflag &= ~(CSIZE | PARENB);
+  
+  /* set speed */
+  speed_t bd;
+  switch (baud) {
+    case 50: bd = B50; break;
+    case 75: bd = B75; break;
+    case 110: bd = B110; break;
+    case 134: bd = B134; break;
+    case 150: bd = B150; break;
+    case 200: bd = B200; break;
+    case 300: bd = B300; break;
+    case 600: bd = B600; break;
+    case 1200: bd = B1200; break;
+    case 1800: bd = B1800; break;
+    case 2400: bd = B2400; break;
+    case 4800: bd = B4800; break;
+    case 9600: bd = B9600; break;
+    case 19200: bd = B19200; break;
+    case 38400: bd = B38400; break;
+    case 57600: bd = B57600; break;
+    case 115200: bd = B115200; break;
+    case 230400: bd = B230400; break;
+    default:
+      close(fd);
+      return E_INVALID_SETTINGS;
+  }
+  
+  if (cfsetspeed(&newtio, bd) < 0) {
+    DEBUG(perror("set baud rate"););
+    close(fd);
+    return E_IO;
+  }
+
+  /* set char size*/
+  switch (char_size) {
+    case 5: newtio.c_cflag |= CS5; break;
+    case 6: newtio.c_cflag |= CS6; break;
+    case 7: newtio.c_cflag |= CS7; break;
+    case 8: newtio.c_cflag |= CS8; break;
+    default:
+      close(fd);
+      return E_INVALID_SETTINGS;
+  }
+  
+  /* use two stop bits */
+  if (two_stop_bits){
+    newtio.c_cflag |= CSTOPB;
+  }
+  
+  /* set parity */
+  switch (parity) {
+    case PARITY_NONE: break;
+    case PARITY_ODD: newtio.c_cflag |= (PARENB | PARODD); break;
+    case PARITY_EVEN: newtio.c_cflag |= PARENB; break;
+    default:
+      close(fd);
+      return E_INVALID_SETTINGS;
+  }
+  
+  if (tcflush(fd, TCIOFLUSH) < 0) {
+    DEBUG(perror("flush serial settings"););
+    close(fd);
+    return E_IO;
+  }
+  
+  if (tcsetattr(fd, TCSANOW, &newtio) < 0) {
+    DEBUG(perror("apply serial settings"););
+    close(fd);
+    return E_IO;
+  }
+  
+  int pipe_fd[2];
+  if (pipe(pipe_fd) < 0) {
+    DEBUG(perror("open pipe"););
+    close(fd);
+    return E_IO;
+  }
+  
+  if (fcntl(pipe_fd[0], F_SETFL, O_NONBLOCK) < 0 || fcntl(pipe_fd[1], F_SETFL, O_NONBLOCK) < 0) {
+    DEBUG(perror("make pipe non-blocking"););
+    close(fd);
+    return E_IO;
+  }
+  
+  struct serial_config* s = malloc(sizeof(s));
+  if (s == NULL) {
+    DEBUG(perror("allocate memory for serial configuration"););
+    close(fd);
+    close(pipe_fd[0]);
+    close(pipe_fd[1]);
+    return E_IO;
+  }
+  
+  s->port_fd = fd;
+  s->pipe_read_fd = pipe_fd[0];
+  s->pipe_write_fd = pipe_fd[1];
+  (*serial) = s;
+  
+  return 0;
+}
+
+int serial_close(struct serial_config* serial) {
+  if (close(serial->pipe_write_fd) < 0) {
+    DEBUG(perror("close write end of pipe"););
+    return E_IO;
+  }
+  if (close(serial->pipe_read_fd) < 0) {
+    DEBUG(perror("close read end of pipe"););
+    return E_IO;
+  }
+  
+  if (flock(serial->port_fd, LOCK_UN) < 0){
+    DEBUG(perror("release lock on port"););
+    return E_IO;
+  }
+  if (close(serial->port_fd) < 0) {
+    DEBUG(perror("close port"););
+    return E_IO;
+  }
+  
+  free(serial);
+  return 0;
+}
+
+int serial_read(struct serial_config* serial, unsigned char* buffer, size_t size) {
+  int port = serial->port_fd;
+  int pipe = serial->pipe_read_fd;
+  
+  fd_set rfds;
+  FD_ZERO(&rfds);
+  FD_SET(port, &rfds);
+  FD_SET(pipe, &rfds);
+  
+  int nfds = pipe + 1;
+  if (pipe < port) nfds = port + 1;
+  
+  int n = select(nfds, &rfds, NULL, NULL, NULL);
+  if (n < 0) {
+    DEBUG(perror("select"););
+    return E_IO;
+  }
+  
+  if (FD_ISSET(port, &rfds)) {
+    int r = read(port, buffer, size);
+    
+    //treat 0 bytes read as an error to avoid problems on disconnect
+    //anyway, after a poll there should be more than 0 bytes available to read
+    if (r <= 0) {
+      DEBUG(perror("read"););
+      return E_IO;
+    }
+    return r;
+  } else if (FD_ISSET(pipe, &rfds)) {
+    return E_INTERRUPT;
+  } else {
+    fputs("select: unknown read sets", stderr);
+    return E_IO;
+  }
+}
+
+int serial_write(struct serial_config* serial, unsigned char* data, size_t size) {
+  int r = write(serial->port_fd, data, size);
+  if (r < 0) {
+    DEBUG(perror("write"););
+    return E_IO;
+  }
+  return r;
+}
+
+int serial_interrupt(struct serial_config* serial) {
+  int data = 0xffffffff;
+  
+  //write to pipe to wake up any blocked read thread (self-pipe trick)
+  if (write(serial->pipe_write_fd, &data, 1) < 0) {
+    DEBUG(perror("write to pipe for interrupt"););
+    return E_IO;
+  }
+  
+  return 0;
+}
+
+
+// JNI bindings
+// ============
+
+inline struct serial_config* j2s(jlong pointer) {
+  return (struct serial_config*) pointer;
+}
+
+inline jlong s2j(struct serial_config* pointer) {
+  return (jlong) pointer;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_open
+  (JNIEnv *env, jclass clazz, jstring port_name, jint baud, jint char_size, jboolean two_stop_bits, jint parity, jlongArray jserialp)
+{ 
+  const char *dev = (*env)->GetStringUTFChars(env, port_name, 0);
+  struct serial_config* serial;
+  int r = serial_open(dev, baud, char_size, two_stop_bits, parity, &serial);
+  (*env)->ReleaseStringUTFChars(env, port_name, dev);
+  
+  long serialp = s2j(serial);
+  (*env)->SetLongArrayRegion(env, jserialp, 0, 1, &serialp);
+  
+  return r;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_close
+  (JNIEnv * env, jclass clazz, jlong serial)
+{
+  serial_close(j2s(serial));
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_read
+  (JNIEnv * env, jclass clazz, jlong serial, jbyteArray jbuffer)
+{
+  
+  jsize size = (*env)->GetArrayLength(env, jbuffer);
+  
+  unsigned char buffer[size];
+  int n = serial_read(j2s(serial), buffer, size);
+  if (n < 0) {
+    return n;
+  }
+  
+  (*env)->SetByteArrayRegion(env, jbuffer, 0, n, (signed char *) buffer);
+  return n;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_write
+  (JNIEnv * env, jclass clazz, jlong serial, jbyteArray jbuffer)
+{
+  unsigned char * buffer = (*env)->GetByteArrayElements(env, jbuffer, NULL);
+  int size = (*env)->GetArrayLength(env, jbuffer);
+  int r = serial_write(j2s(serial), buffer, size);
+  
+  (*env)->ReleaseByteArrayElements(env, jbuffer, buffer, JNI_ABORT);
+  
+  return r;
+}
+
+JNIEXPORT jint JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_interrupt
+  (JNIEnv * env, jclass clazz, jlong serial)
+{
+  return serial_interrupt(j2s(serial));
+}
+
+JNIEXPORT void JNICALL Java_com_github_jodersky_flow_internal_NativeSerial_debug
+  (JNIEnv *env, jclass clazz, jboolean value)
+{
+  serial_debug((bool) value);
+}
diff --git a/flow/src/main/native/windows/README b/flow/src/main/native/windows/README
new file mode 100644
index 0000000..3d24410
--- /dev/null
+++ b/flow/src/main/native/windows/README
@@ -0,0 +1 @@
+The contents of the file flow.c were found in the avrdude project. They look like they may be a good starting point for serial communication on windows.
diff --git a/flow/src/main/native/windows/flow.c.disabled b/flow/src/main/native/windows/flow.c.disabled
new file mode 100644
index 0000000..86a267c
--- /dev/null
+++ b/flow/src/main/native/windows/flow.c.disabled
@@ -0,0 +1,416 @@
+/*
+ * avrdude - A Downloader/Uploader for AVR device programmers
+ * Copyright (C) 2003, 2004  Martin J. Thomas  <mthomas@rhrk.uni-kl.de>
+ * Copyright (C) 2006  Joerg Wunsch <j@uriah.heep.sax.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* $Id$ */
+
+/*
+ * Native Win32 serial interface for avrdude.
+ */
+
+#include "avrdude.h"
+
+#if defined(WIN32NATIVE)
+
+#include <windows.h>
+#include <stdio.h>
+#include <ctype.h>   /* for isprint */
+
+#include "serial.h"
+
+long serial_recv_timeout = 5000; /* ms */
+
+#define W32SERBUFSIZE 1024
+
+struct baud_mapping {
+  long baud;
+  DWORD speed;
+};
+
+/* HANDLE hComPort=INVALID_HANDLE_VALUE; */
+
+static struct baud_mapping baud_lookup_table [] = {
+  { 1200,   CBR_1200 },
+  { 2400,   CBR_2400 },
+  { 4800,   CBR_4800 },
+  { 9600,   CBR_9600 },
+  { 19200,  CBR_19200 },
+  { 38400,  CBR_38400 },
+  { 57600,  CBR_57600 },
+  { 115200, CBR_115200 },
+  { 0,      0 }                 /* Terminator. */
+};
+
+static DWORD serial_baud_lookup(long baud)
+{
+  struct baud_mapping *map = baud_lookup_table;
+
+  while (map->baud) {
+    if (map->baud == baud)
+      return map->speed;
+    map++;
+  }
+
+  /*
+   * If a non-standard BAUD rate is used, issue
+   * a warning (if we are verbose) and return the raw rate
+   */
+  if (verbose > 0)
+      fprintf(stderr, "%s: serial_baud_lookup(): Using non-standard baud rate: %ld",
+              progname, baud);
+
+  return baud;
+}
+
+
+static BOOL serial_w32SetTimeOut(HANDLE hComPort, DWORD timeout) // in ms
+{
+	COMMTIMEOUTS ctmo;
+	ZeroMemory (&ctmo, sizeof(COMMTIMEOUTS));
+	ctmo.ReadIntervalTimeout = timeout;
+	ctmo.ReadTotalTimeoutMultiplier = timeout;
+	ctmo.ReadTotalTimeoutConstant = timeout;
+
+	return SetCommTimeouts(hComPort, &ctmo);
+}
+
+static int ser_setspeed(union filedescriptor *fd, long baud)
+{
+	DCB dcb;
+	HANDLE hComPort = (HANDLE)fd->pfd;
+
+	ZeroMemory (&dcb, sizeof(DCB));
+	dcb.DCBlength = sizeof(DCB);
+	dcb.BaudRate = serial_baud_lookup (baud);
+	dcb.fBinary = 1;
+	dcb.fDtrControl = DTR_CONTROL_DISABLE;
+	dcb.fRtsControl = RTS_CONTROL_DISABLE;
+	dcb.ByteSize = 8;
+	dcb.Parity = NOPARITY;
+	dcb.StopBits = ONESTOPBIT;
+
+	if (!SetCommState(hComPort, &dcb))
+		return -1;
+
+	return 0;
+}
+
+
+static int ser_open(char * port, long baud, union filedescriptor *fdp)
+{
+	LPVOID lpMsgBuf;
+	HANDLE hComPort=INVALID_HANDLE_VALUE;
+	char *newname = 0;
+
+	/*
+	 * If the port is of the form "net:<host>:<port>", then
+	 * handle it as a TCP connection to a terminal server.
+	 *
+	 * This is curently not implemented for Win32.
+	 */
+	if (strncmp(port, "net:", strlen("net:")) == 0) {
+		fprintf(stderr,
+			"%s: ser_open(): network connects are currently not"
+			"implemented for Win32 environments\n",
+			progname);
+		return -1;
+	}
+
+	if (strncasecmp(port, "com", strlen("com")) == 0) {
+
+	    // prepend "\\\\.\\" to name, required for port # >= 10
+	    newname = malloc(strlen("\\\\.\\") + strlen(port) + 1);
+
+	    if (newname == 0) {
+		fprintf(stderr,
+			"%s: ser_open(): out of memory\n",
+			progname);
+		exit(1);
+	    }
+	    strcpy(newname, "\\\\.\\");
+	    strcat(newname, port);
+
+	    port = newname;
+	}
+
+	hComPort = CreateFile(port, GENERIC_READ | GENERIC_WRITE, 0, NULL,
+		OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		FormatMessage( 
+			FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+			FORMAT_MESSAGE_FROM_SYSTEM | 
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL,
+			GetLastError(),
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+			(LPTSTR) &lpMsgBuf,
+			0,
+			NULL);
+		fprintf(stderr, "%s: ser_open(): can't open device \"%s\": %s\n",
+				progname, port, (char*)lpMsgBuf);
+		LocalFree( lpMsgBuf );
+		return -1;
+	}
+
+	if (!SetupComm(hComPort, W32SERBUFSIZE, W32SERBUFSIZE))
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set buffers for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+        fdp->pfd = (void *)hComPort;
+	if (ser_setspeed(fdp, baud) != 0)
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set com-state for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+	if (!serial_w32SetTimeOut(hComPort,0))
+	{
+		CloseHandle(hComPort);
+		fprintf(stderr, "%s: ser_open(): can't set initial timeout for \"%s\"\n",
+				progname, port);
+		return -1;
+	}
+
+	if (newname != 0) {
+	    free(newname);
+	}
+	return 0;
+}
+
+
+static void ser_close(union filedescriptor *fd)
+{
+	HANDLE hComPort=(HANDLE)fd->pfd;
+	if (hComPort != INVALID_HANDLE_VALUE)
+		CloseHandle (hComPort);
+
+	hComPort = INVALID_HANDLE_VALUE;
+}
+
+static int ser_set_dtr_rts(union filedescriptor *fd, int is_on)
+{
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+	if (is_on) {
+		EscapeCommFunction(hComPort, SETDTR);
+		EscapeCommFunction(hComPort, SETRTS);
+	} else {
+		EscapeCommFunction(hComPort, CLRDTR);
+		EscapeCommFunction(hComPort, CLRRTS);
+	}
+	return 0;
+}
+
+
+static int ser_send(union filedescriptor *fd, unsigned char * buf, size_t buflen)
+{
+	size_t len = buflen;
+	unsigned char c='\0';
+	DWORD written;
+        unsigned char * b = buf;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_send(): port not open\n",
+              progname); 
+		exit(1);
+	}
+
+	if (!len)
+  return 0;
+
+	if (verbose > 3)
+	{
+		fprintf(stderr, "%s: Send: ", progname);
+
+		while (len) {
+			c = *b;
+			if (isprint(c)) {
+				fprintf(stderr, "%c ", c);
+			}
+			else {
+				fprintf(stderr, ". ");
+			}
+			fprintf(stderr, "[%02x] ", c);
+			b++;
+			len--;
+		}
+      fprintf(stderr, "\n");
+	}
+	
+	serial_w32SetTimeOut(hComPort,500);
+
+	if (!WriteFile (hComPort, buf, buflen, &written, NULL)) {
+		fprintf(stderr, "%s: ser_send(): write error: %s\n",
+              progname, "sorry no info avail"); // TODO
+		exit(1);
+	}
+
+	if (written != buflen) {
+		fprintf(stderr, "%s: ser_send(): size/send mismatch\n",
+              progname); 
+		exit(1);
+	}
+
+	return 0;
+}
+
+
+static int ser_recv(union filedescriptor *fd, unsigned char * buf, size_t buflen)
+{
+	unsigned char c;
+	unsigned char * p = buf;
+	DWORD read;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+	
+	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_read(): port not open\n",
+              progname); 
+		exit(1);
+	}
+	
+	serial_w32SetTimeOut(hComPort, serial_recv_timeout);
+	
+	if (!ReadFile(hComPort, buf, buflen, &read, NULL)) {
+		LPVOID lpMsgBuf;
+		FormatMessage( 
+			FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+			FORMAT_MESSAGE_FROM_SYSTEM | 
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL,
+			GetLastError(),
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+			(LPTSTR) &lpMsgBuf,
+			0,
+			NULL 	);
+		fprintf(stderr, "%s: ser_recv(): read error: %s\n",
+			      progname, (char*)lpMsgBuf);
+		LocalFree( lpMsgBuf );
+		exit(1);
+	}
+
+	/* time out detected */
+	if (read == 0) {
+		if (verbose > 1)
+		fprintf(stderr,
+			"%s: ser_recv(): programmer is not responding\n",
+			progname);
+		return -1;
+	}
+
+	p = buf;
+
+	if (verbose > 3)
+	{
+		fprintf(stderr, "%s: Recv: ", progname);
+
+		while (read) {
+			c = *p;
+			if (isprint(c)) {
+				fprintf(stderr, "%c ", c);
+			}
+			else {
+				fprintf(stderr, ". ");
+			}
+			fprintf(stderr, "[%02x] ", c);
+
+			p++;
+			read--;
+		}
+		fprintf(stderr, "\n");
+	}
+  return 0;
+}
+
+
+static int ser_drain(union filedescriptor *fd, int display)
+{
+	// int rc;
+	unsigned char buf[10];
+	BOOL readres;
+	DWORD read;
+
+	HANDLE hComPort=(HANDLE)fd->pfd;
+
+  	if (hComPort == INVALID_HANDLE_VALUE) {
+		fprintf(stderr, "%s: ser_drain(): port not open\n",
+              progname); 
+		exit(1);
+	}
+
+	serial_w32SetTimeOut(hComPort,250);
+  
+	if (display) {
+		fprintf(stderr, "drain>");
+	}
+
+	while (1) {
+		readres=ReadFile(hComPort, buf, 1, &read, NULL);
+		if (!readres) {
+			LPVOID lpMsgBuf;
+			FormatMessage( 
+				FORMAT_MESSAGE_ALLOCATE_BUFFER | 
+				FORMAT_MESSAGE_FROM_SYSTEM | 
+				FORMAT_MESSAGE_IGNORE_INSERTS,
+				NULL,
+				GetLastError(),
+				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+				(LPTSTR) &lpMsgBuf,
+				0,
+				NULL 	);
+			fprintf(stderr, "%s: ser_drain(): read error: %s\n",
+					  progname, (char*)lpMsgBuf);
+			LocalFree( lpMsgBuf );
+			exit(1);
+		}
+
+		if (read) { // data avail
+			if (display) fprintf(stderr, "%02x ", buf[0]);
+		}
+		else { // no more data
+			if (display) fprintf(stderr, "<drain\n");
+			break;
+		}
+	} // while
+  return 0;
+}
+
+struct serial_device serial_serdev =
+{
+  .open = ser_open,
+  .setspeed = ser_setspeed,
+  .close = ser_close,
+  .send = ser_send,
+  .recv = ser_recv,
+  .drain = ser_drain,
+  .set_dtr_rts = ser_set_dtr_rts,
+  .flags = SERDEV_FL_CANSETSPEED,
+};
+
+struct serial_device *serdev = &serial_serdev;
+
+#endif /* WIN32NATIVE */ 
diff --git a/flow/src/main/scala/com/github/jodersky/flow/Parity.scala b/flow/src/main/scala/com/github/jodersky/flow/Parity.scala
new file mode 100644
index 0000000..9bf52a6
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/Parity.scala
@@ -0,0 +1,9 @@
+package com.github.jodersky.flow
+
+/** Specifies available parities used in serial communication. */
+object Parity extends Enumeration {
+  type Parity = Value
+  val None = Value(0)
+  val Odd = Value(1)
+  val Even = Value(2)
+}
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/Serial.scala b/flow/src/main/scala/com/github/jodersky/flow/Serial.scala
new file mode 100644
index 0000000..abc8f39
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/Serial.scala
@@ -0,0 +1,108 @@
+package com.github.jodersky.flow
+
+import akka.actor.ActorRef
+import akka.actor.ExtensionKey
+import akka.util.ByteString
+
+/** Defines messages used by flow's serial IO layer. */
+object Serial extends ExtensionKey[SerialExt] {
+
+  /** A message extending this trait is to be viewed as a command, an out-bound message issued by the client to flow's API. */
+  trait Command
+
+  /** A message extending this trait is to be viewed as an event, an in-bound message issued by flow to the client. */
+  trait Event
+
+  /** A command has failed. */
+  case class CommandFailed(command: Command, reason: Throwable) extends Event
+
+  /**
+   * Open a new serial port.
+   *
+   * Send this command to the serial manager to request the opening of a serial port. The manager will
+   * attempt to open a serial port with the specified parameters and, if successful, create a `SerialOperator` actor associated to the port.
+   * The operator actor acts as an intermediate to the underlying native serial port, dealing with threading issues and dispatching messages.
+   *
+   * In case the port is successfully opened, the operator will respond with an `Opened` message.
+   * In case the port cannot be opened, the manager will respond with a `CommandFailed` message.
+   *
+   * @param settings settings of serial port to open
+   */
+  case class Open(settings: SerialSettings) extends Command
+
+  /**
+   * A port has been successfully opened.
+   *
+   * Event sent by a port operator, indicating that a serial port was successfully opened. The sender
+   * of this message is the operator associated to the given serial port. Furthermore, an additional reference
+   * to the operator is provided in this class' `operator` field.
+   *
+   * @param settings settings of port that was opened
+   * @param operator operator associated with the serial port
+   */
+  case class Opened(settings: SerialSettings, operator: ActorRef) extends Event
+
+  /**
+   * Register an actor to receive events.
+   *
+   * Send this command to a serial operator to register an actor for notification on the reception of data on the operator's associated port.
+   * Upon reception, data will be sent by the operator to registered actors in form of `Received` events.
+   *
+   * @param receiver actor to register
+   */
+  case class Register(receiver: ActorRef) extends Command
+
+  /**
+   * Unregister an actor from receiving events.
+   *
+   * Send this command to a serial operator to unregister an actor for notification on the reception of data on the operator's associated port.
+   *
+   * @param receiver actor to unregister
+   */
+  case class Unregister(receiver: ActorRef) extends Command
+
+  /**
+   * Data has been received.
+   *
+   * Event sent by an operator, indicating that data was received on the operator's serial port.
+   * Clients must register (see `Register`) with a serial operator to receive these events.
+   *
+   * @param data data received on the port
+   */
+  case class Received(data: ByteString) extends Event
+
+  /**
+   * Write data to a serial port.
+   *
+   * Send this command to an operator to write the given data to its associated serial port.
+   * An acknowledgment may be set, in which case it is sent back to the sender on a successful write.
+   * Note that a successful write does not guarantee the actual transmission of data through the serial port,
+   * it merely guarantees that the data has been stored in the operating system's kernel buffer, ready to
+   * be written.
+   *
+   * @param data data to be written to port
+   * @param ack acknowledgment sent back to sender once data has been enqueued in kernel for sending
+   */
+  case class Write(data: ByteString, ack: Event = NoAck) extends Command
+
+  /**
+   *  Special type of acknowledgment that is not sent back.
+   */
+  case object NoAck extends Event
+
+  /**
+   *  Request closing of port.
+   *
+   *  Send this command to an operator to close its associated port. The operator will respond
+   *  with a `Closed` message upon closing the serial port.
+   */
+  case object Close extends Command
+
+  /**
+   * A port has been closed.
+   *
+   * Event sent from operator, indicating that its port has been closed.
+   */
+  case object Closed extends Event
+
+}
diff --git a/flow/src/main/scala/com/github/jodersky/flow/SerialExt.scala b/flow/src/main/scala/com/github/jodersky/flow/SerialExt.scala
new file mode 100644
index 0000000..826a4e9
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/SerialExt.scala
@@ -0,0 +1,10 @@
+package com.github.jodersky.flow
+
+import akka.actor.ExtendedActorSystem
+import akka.actor.Props
+import akka.io.IO
+
+/** Provides the serial IO manager. */
+class SerialExt(system: ExtendedActorSystem) extends IO.Extension {
+  lazy val manager = system.actorOf(Props(classOf[SerialManager]), name = "IO-SERIAL")
+}
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/SerialManager.scala b/flow/src/main/scala/com/github/jodersky/flow/SerialManager.scala
new file mode 100644
index 0000000..b3128ac
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/SerialManager.scala
@@ -0,0 +1,55 @@
+package com.github.jodersky.flow
+
+import java.io.IOException
+
+import scala.util.Failure
+import scala.util.Success
+import scala.util.Try
+
+import com.github.jodersky.flow.internal.InternalSerial
+
+import Serial._
+import akka.actor.Actor
+import akka.actor.ActorLogging
+import akka.actor.OneForOneStrategy
+import akka.actor.Props
+import akka.actor.SupervisorStrategy.Escalate
+import akka.actor.SupervisorStrategy.Stop
+import akka.actor.actorRef2Scala
+
+/**
+ * Actor that manages serial port creation. Once opened, a serial port is handed over to
+ * a dedicated operator actor that acts as an intermediate between client code and the native system serial port.
+ * @see SerialOperator
+ */
+class SerialManager extends Actor with ActorLogging {
+  import SerialManager._
+  import context._
+
+  override val supervisorStrategy =
+    OneForOneStrategy() {
+      case _: IOException => Stop
+      case _: Exception => Escalate
+    }
+
+  def receive = {
+    case c @ Open(s) => Try { InternalSerial.open(s.port, s.baud, s.characterSize, s.twoStopBits, s.parity.id) } match {
+      case Failure(t) => sender ! CommandFailed(c, t)
+      case Success(serial) => {
+        val operator = context.actorOf(SerialOperator(serial), name = escapePortString(s.port))
+        val settings = SerialSettings(serial.port, serial.baud, serial.characterSize, serial.twoStopBits, Parity(serial.parity)) 
+        sender.tell(Opened(settings, operator), operator)
+      }
+    }
+  }
+
+}
+
+object SerialManager {
+
+  private def escapePortString(port: String) = port collect {
+    case '/' => '-'
+    case c => c
+  }
+
+}
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/SerialOperator.scala b/flow/src/main/scala/com/github/jodersky/flow/SerialOperator.scala
new file mode 100644
index 0000000..3ac50c0
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/SerialOperator.scala
@@ -0,0 +1,101 @@
+package com.github.jodersky.flow
+
+import java.io.IOException
+import com.github.jodersky.flow.internal.InternalSerial
+import Serial._
+import akka.actor.Actor
+import akka.actor.ActorLogging
+import akka.actor.ActorRef
+import akka.actor.Terminated
+import akka.actor.actorRef2Scala
+import akka.util.ByteString
+import scala.collection.mutable.HashSet
+import akka.actor.Props
+
+/**
+ * Operator associated to an open serial port. All communication with a port is done via an operator. Operators are created though the serial manager.
+ *  @see SerialManager
+ */
+class SerialOperator(serial: InternalSerial) extends Actor with ActorLogging {
+  import SerialOperator._
+  import context._
+
+  private val receivers = new HashSet[ActorRef]
+  private val receiversLock = new Object
+  private def tellAllReceivers(msg: Any) = receiversLock.synchronized {
+    receivers.foreach { receiver =>
+      receiver ! msg
+    }
+  }
+
+  private object Reader extends Thread {
+    def readLoop() = {
+      var continueReading = true
+      while (continueReading) {
+        try {
+          val data = ByteString(serial.read())
+          tellAllReceivers(Received(data))
+        } catch {
+
+          //port is closing, stop thread gracefully
+          case ex: PortInterruptedException => {
+            continueReading = false
+          }
+
+          //something else went wrong stop and tell actor
+          case ex: Exception => {
+            continueReading = false
+            self ! ReadException(ex)
+          }
+        }
+      }
+    }
+
+    def name = this.getName()
+
+    override def run() {
+      this.setName("flow-reader " + serial.port)
+      readLoop()
+    }
+  }
+
+  override def preStart() = {
+    Reader.start()
+  }
+
+  override def postStop = {
+    serial.close()
+  }
+
+  def receive: Receive = {
+
+    case Register(actor) => receiversLock.synchronized {
+      receivers += actor
+    }
+
+    case Unregister(actor) => receiversLock.synchronized {
+      receivers -= actor
+    }
+
+    case Write(data, ack) => {
+      val sent = serial.write(data.toArray)
+      if (ack != NoAck) sender ! ack
+    }
+
+    case Close => {
+      tellAllReceivers(Closed)
+      context stop self
+    }
+
+    //go down with reader thread
+    case ReadException(ex) => throw ex
+
+  }
+
+}
+
+object SerialOperator {
+  private case class ReadException(ex: Exception)
+  
+  def apply(serial: InternalSerial) = Props(classOf[SerialOperator], serial)
+}
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/SerialSettings.scala b/flow/src/main/scala/com/github/jodersky/flow/SerialSettings.scala
new file mode 100644
index 0000000..a3bc5e4
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/SerialSettings.scala
@@ -0,0 +1,11 @@
+package com.github.jodersky.flow
+
+/**
+ * Groups settings used in communication over a serial port.
+ * @param port name of serial port
+ * @param baud baud rate to use with serial port
+ * @param characterSize size of a character of the data sent through the serial port
+ * @param twoStopBits set to use two stop bits instead of one
+ * @param parity type of parity to use with serial port
+ */
+case class SerialSettings(port: String, baud: Int, characterSize: Int = 8, twoStopBits: Boolean = false, parity: Parity.Parity = Parity.None)
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/exceptions.scala b/flow/src/main/scala/com/github/jodersky/flow/exceptions.scala
new file mode 100644
index 0000000..5923ba6
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/exceptions.scala
@@ -0,0 +1,21 @@
+package com.github.jodersky.flow
+
+import java.io.IOException
+
+/** The requested port could not be found. */
+class NoSuchPortException(message: String) extends Exception(message)
+
+/** The requested port is in use by someone else. */
+class PortInUseException(message: String) extends Exception(message)
+
+/** Permissions are not sufficient to open a serial port. */
+class AccessDeniedException(message: String) extends Exception(message)
+
+/** The settings specified are invalid. */
+class InvalidSettingsException(message: String) extends Exception(message)
+
+/** A blocking operation on a port was interrupted, most likely indicating that the port is closing. */
+class PortInterruptedException(message: String) extends Exception(message)
+
+/** The specified port has been closed. */
+class PortClosedException(message: String) extends Exception(message)
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/internal/InternalSerial.scala b/flow/src/main/scala/com/github/jodersky/flow/internal/InternalSerial.scala
new file mode 100644
index 0000000..e69f91a
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/internal/InternalSerial.scala
@@ -0,0 +1,92 @@
+package com.github.jodersky.flow.internal
+
+import java.io.IOException
+import com.github.jodersky.flow._
+import java.util.concurrent.atomic.AtomicBoolean
+
+/** Wraps `NativeSerial` in a more object-oriented style, still quite low level. */
+class InternalSerial private (val port: String, val baud: Int, val characterSize: Int, val twoStopBits: Boolean, val parity: Int, private val pointer: Long) {
+  import InternalSerial._
+
+  private val reading = new AtomicBoolean(false)
+  private val writing = new AtomicBoolean(false)
+  private val closed = new AtomicBoolean(false)
+
+  /** Closes the underlying serial connection. Any threads blocking on read or write will return. */
+  def close(): Unit = synchronized {
+    if (!closed.get()) {
+      closed.set(true)
+      except(NativeSerial.interrupt(pointer), port)
+      if (writing.get()) wait()
+      if (reading.get()) wait()
+      except(NativeSerial.close(pointer), port)
+    }
+  }
+
+  /**
+   * Read data from underlying serial connection.
+   * @throws PortInterruptedException if port is closed from another thread
+   */
+  def read(): Array[Byte] = if (!closed.get) {
+    reading.set(true)
+    try {
+      val buffer = new Array[Byte](100)
+      val bytesRead = except(NativeSerial.read(pointer, buffer), port)
+      buffer take bytesRead
+    } finally {
+      synchronized {
+        reading.set(false)
+        if (closed.get) notify()
+      }
+    }
+  } else {
+    throw new PortClosedException(s"port ${port} is already closed")
+  }
+
+  /**
+   * Write data to underlying serial connection.
+   * @throws PortInterruptedException if port is closed from another thread
+   */
+  def write(data: Array[Byte]): Array[Byte] = if (!closed.get) {
+    writing.set(true)
+    try {
+      val bytesWritten = except(NativeSerial.write(pointer, data), port)
+      data take bytesWritten
+    } finally {
+      synchronized {
+        writing.set(false)
+        if (closed.get) notify()
+      }
+    }
+  } else {
+    throw new PortClosedException(s"port ${port} is already closed")
+  }
+
+}
+
+object InternalSerial {
+  import NativeSerial._
+
+  /** Transform error code to exception if necessary. */
+  private def except(result: Int, port: String): Int = result match {
+    case E_IO => throw new IOException(port)
+    case E_ACCESS_DENIED => throw new AccessDeniedException(port)
+    case E_BUSY => throw new PortInUseException(port)
+    case E_INVALID_SETTINGS => throw new InvalidSettingsException("the provided settings are invalid: be sure to use standard baud rate, character size and parity.")
+    case E_INTERRUPT => throw new PortInterruptedException(port)
+    case E_NO_PORT => throw new NoSuchPortException(port)
+    case error if error < 0 => throw new IOException(s"unknown error code: ${error}")
+    case success => success
+  }
+
+  /** Open a new connection to a serial port. */
+  def open(port: String, baud: Int, characterSize: Int, twoStopBits: Boolean, parity: Int): InternalSerial = synchronized {
+    val pointer = new Array[Long](1)
+    except(NativeSerial.open(port, baud, characterSize, twoStopBits, parity, pointer), port)
+    new InternalSerial(port, baud, characterSize, twoStopBits, parity, pointer(0))
+  }
+
+  /** Set debugging for all serial connections. Debugging results in printing extra messages from the native library in case of errors. */
+  def debug(value: Boolean) = NativeSerial.debug(value)
+
+}
\ No newline at end of file
diff --git a/flow/src/main/scala/com/github/jodersky/flow/internal/NativeLoader.scala b/flow/src/main/scala/com/github/jodersky/flow/internal/NativeLoader.scala
new file mode 100644
index 0000000..034be96
--- /dev/null
+++ b/flow/src/main/scala/com/github/jodersky/flow/internal/NativeLoader.scala
@@ -0,0 +1,38 @@
+package com.github.jodersky.flow.internal
+
+import java.io.File
+import java.io.FileOutputStream
+import scalax.file.Path
+import scalax.io.Resource
+import scala.util.Try
+
+/** Handles loading of the current platform's native library for flow. */
+object NativeLoader {
+
+  def extract(): Option[File] = {
+    val os = System.getProperty("os.name").toLowerCase.filter(_ != ' ')
+    val arch = System.getProperty("os.arch").toLowerCase
+    val fqlib = System.mapLibraryName("flow") //fully qualified library name
+
+    val in = NativeLoader.getClass().getResourceAsStream(s"/native/${arch}-${os}/${fqlib}")
+    if (in == null) return None
+
+    val temp = Path.createTempFile()
+    Resource.fromInputStream(in).copyDataTo(temp)
+    temp.fileOption
+  }
+
+  def loadFromJar() = extract() match {
+    case Some(file) => System.load(file.getAbsolutePath)
+    case None => throw new UnsatisfiedLinkError("cannot extract native library, the native library may not exist for your specific os/architecture combination")
+  }
+
+  def load = {
+    try {
+      System.loadLibrary("flow")
+    } catch {
+      case ex: UnsatisfiedLinkError => loadFromJar()
+    }
+  }
+
+}
\ No newline at end of file