FreeModBus is now integrated with the Nuttx configuration system

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4961 42af7a65-404d-4744-a932-0658087f49c3

18 files changed, 956 insertions, 74 deletions

diff --git a/apps/modbus/Kconfig b/apps/modbus/Kconfig
new file mode 100644
index 000000000..839466930
--- /dev/null
+++ b/apps/modbus/Kconfig
@@ -0,0 +1,139 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+comment "FreeModbus"
+
+config MB_ASCII_ENABLED
+	bool "Modbus ASCII support"
+	depends on MODBUS
+	default y
+
+config MB_RTU_ENABLED
+	bool "Modbus RTU support"
+	depends on MODBUS
+	default y
+
+config MB_TCP_ENABLED
+	bool "Modbus TCP support"
+	depends on MODBUS
+	default y
+
+config MB_ASCII_TIMEOUT_SEC
+	int "Character timeout"
+	depends on MB_ASCII_ENABLED
+	default 1
+	---help---
+		Character timeout value for Modbus ASCII
+
+		The character timeout value is not fixed for Modbus ASCII and is therefore
+		a configuration option. It should be set to the maximum expected delay
+		time of the network.
+
+config MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS
+	int "Timeout to wait before sending"
+	depends on MB_ASCII_ENABLED
+	default 0
+	---help---
+		Timeout to wait in ASCII prior to enabling transmitter
+
+		If defined the function calls vMBPortSerialDelay with the argument
+		MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS to allow for a delay before
+		the serial transmitter is enabled. This is required because some
+		targets are so fast that there is no time between receiving and
+		transmitting the frame. If the master is to slow with enabling its 
+		receiver then he will not receive the response correctly.
+
+config MB_FUNC_HANDLERS_MAX
+	int "Maximum number of Modbus functions"
+	depends on MODBUS
+	default 16
+	---help---
+		Maximum number of Modbus functions codes the protocol stack should support.
+
+		The maximum number of supported Modbus functions must be greater than
+		the sum of all enabled functions in this file and custom function
+		handlers. If set to small adding more functions will fail.
+
+config MB_FUNC_OTHER_REP_SLAVEID_BUF
+	int "Size of Slave ID report buffer"
+	depends on MB_FUNC_OTHER_REP_SLAVEID_ENABLED
+	default 32
+	---help---
+		Number of bytes which should be allocated for the Report Slave ID command.
+
+		This number limits the maximum size of the additional segment in the
+		report slave id function. See eMBSetSlaveID() for more information on
+		how to set this value. It is only used if MB_FUNC_OTHER_REP_SLAVEID_ENABLED
+		is set to 1.
+
+config MB_FUNC_OTHER_REP_SLAVEID_ENABLED
+	bool "Report Slave ID function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Report Slave ID function should be enabled.
+
+config MB_FUNC_READ_INPUT_ENABLED
+	bool "Read Input Registers function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Read Input Registers function should be enabled.
+
+config MB_FUNC_READ_HOLDING_ENABLED
+	bool "Read Holding Registers function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Read Holding Registers function should be enabled.
+
+config MB_FUNC_WRITE_HOLDING_ENABLED
+	bool "Write Single Register function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Write Single Register function should be enabled.
+
+config MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED
+	bool "Write Multiple registers function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Write Multiple registers function should be enabled.
+
+config MB_FUNC_READ_COILS_ENABLED
+	bool "Read Coils function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Read Coils function should be enabled.
+
+config MB_FUNC_WRITE_COIL_ENABLED
+	bool "Write Coils function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Write Coils function should be enabled.
+
+config MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED
+	bool "Write Multiple Coils function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Write Multiple Coils function should be enabled.
+
+config MB_FUNC_READ_DISCRETE_INPUTS_ENABLED
+	bool "Read Discrete Inputs function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Read Discrete Inputs function should be enabled.
+
+config MB_FUNC_READWRITE_HOLDING_ENABLED
+	bool "Read/Write Multiple Registers function"
+	depends on MODBUS
+	default y
+	---help---
+		If the Read/Write Multiple Registers function should be enabled.
diff --git a/apps/modbus/README.txt b/apps/modbus/README.txt
index 8ecf3f8db..da9b42fd4 100644
--- a/apps/modbus/README.txt
+++ b/apps/modbus/README.txt
@@ -1,14 +1,14 @@
 apps/modbus README
 ==================
 
-This directory contains a port of last open source version of freemodbus
-(BSD license).  The code in this directory is a subset of freemodbus version
+This directory contains a port of last open source version of FreeModBus
+(BSD license).  The code in this directory is a subset of FreeModBus version
 1.5.0 (June 6, 2010) that can be downloaded in its entirety from http://developer.berlios.de/project/showfiles.php?group_id=6120.
 
 Directory Structure/Relation to freemodbus-v1.5.0
 -------------------------------------------------
 
-The original freemodbus download consists of several directories.  This
+The original FreeModBus download consists of several directories.  This
 subset takes only the contents of one directory, modbus/, that implements
 the core modbus logic and integrates that directory into the NuttX build
 system.  The mapping between freemodbus-v1.5.0 and the nuttx directories
@@ -41,14 +41,58 @@ directory except that (1) it may include modifications for the integration
 with NuttX and (2) the modbus/include directory was moved to apps/modbus.
 
 The original, unmodified freemodbus-v1.5.0 was checked in as SVN revision
-4937
+4960.
 
 The other directory here, nuttx/, implements the NuttX modbus interface.
 It derives from the freemodbus-v1.5.0/demo/LINUX/port directory.
 
+Configuration Options
+=====================
+
+In the original freemodbus-v1.5.0 release, the FreeModBus configuration
+was controlled by the header file mbconfig.h.  This header file was
+eliminated (post revision 4960) and the FreeModBus configuration
+was integrated into the NuttX configuration system.
+
+The NuttX-named configuration options that are available include:
+
+    CONFIG_MB_ASCII_ENABLED - Modbus ASCII support
+    CONFIG_MB_RTU_ENABLED - Modbus RTU support
+    CONFIG_MB_TCP_ENABLED - Modbus TCP support
+    CONFIG_MB_ASCII_TIMEOUT_SEC - Character timeout value for Modbus ASCII. The
+      character timeout value is not fixed for Modbus ASCII and is therefore
+      a configuration option. It should be set to the maximum expected delay
+      time of the network. Default 1
+    CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS - Timeout to wait in ASCII prior
+      to enabling transmitter.  If defined the function calls
+      vMBPortSerialDelay with the argument CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS
+      to allow for a delay before the serial transmitter is enabled. This is
+      required because some targets are so fast that there is no time between
+      receiving and transmitting the frame. If the master is to slow with
+      enabling its receiver then he will not receive the response correctly.
+
+    CONFIG_MB_FUNC_HANDLERS_MAX - Maximum number of Modbus functions codes the
+      protocol stack should support. The maximum number of supported Modbus
+      functions must be greater than the sum of all enabled functions in this
+      file and custom function handlers. If set to small adding more functions
+      will fail.
+
+    CONFIG_MB_FUNC_OTHER_REP_SLAVEID_BUF - Number of bytes which should be allocated for the Report Slave ID command. This number limits the maximum size of the additional segment in the report slave id function. See eMBSetSlaveID() for more information on how to set this value. It is only used if CONFIG_MB_FUNC_OTHER_REP_SLAVEID_ENABLED is set to 1.
+
+    CONFIG_MB_FUNC_OTHER_REP_SLAVEID_ENABLED - If the Report Slave ID function should be enabled.
+    CONFIG_MB_FUNC_READ_INPUT_ENABLED - If the Read Input Registers function should be enabled.
+    CONFIG_MB_FUNC_READ_HOLDING_ENABLED - If the Read Holding Registers function should be enabled.
+    CONFIG_MB_FUNC_WRITE_HOLDING_ENABLED - If the Write Single Register function should be enabled.
+    CONFIG_MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED - If the Write Multiple registers function should be enabled.
+    CONFIG_MB_FUNC_READ_COILS_ENABLED - If the Read Coils function should be enabled.
+    CONFIG_MB_FUNC_WRITE_COIL_ENABLED - If the Write Coils function should be enabled.
+    CONFIG_MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED - If the Write Multiple Coils function should be enabled.
+    CONFIG_MB_FUNC_READ_DISCRETE_INPUTS_ENABLED - If the Read Discrete Inputs function should be enabled.
+    CONFIG_MB_FUNC_READWRITE_HOLDING_ENABLED - If the Read/Write Multiple Registers function should be enabled.
+
 Note
 ====
 
-The developer of freemodbus, Christian Walter, is still developing Modbus
+The developer of FreeModBus, Christian Walter, is still developing Modbus
 libraries, although they are now commercial.  See
 http://www.embedded-solutions.at/ for further information.
diff --git a/apps/modbus/ascii/mbascii.c b/apps/modbus/ascii/mbascii.c
index c513457ea..c334d6a9a 100644
--- a/apps/modbus/ascii/mbascii.c
+++ b/apps/modbus/ascii/mbascii.c
@@ -29,22 +29,22 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
 
 /* ----------------------- Modbus includes ----------------------------------*/
 #include "mb.h"
-#include "mbconfig.h"
 #include "mbascii.h"
 #include "mbframe.h"
 
 #include "mbcrc.h"
 #include "mbport.h"
 
-#if MB_ASCII_ENABLED > 0
+#ifdef CONFIG_MB_ASCII_ENABLED
 
 /* ----------------------- Defines ------------------------------------------*/
 #define MB_ASCII_DEFAULT_CR     '\r'    /*!< Default CR character for Modbus ASCII. */
@@ -117,7 +117,7 @@ eMBASCIIInit( UCHAR ucSlaveAddress, UCHAR ucPort, ULONG ulBaudRate, eMBParity eP
     {
         eStatus = MB_EPORTERR;
     }
-    else if( xMBPortTimersInit( MB_ASCII_TIMEOUT_SEC * 20000UL ) != TRUE )
+    else if( xMBPortTimersInit( CONFIG_MB_ASCII_TIMEOUT_SEC * 20000UL ) != TRUE )
     {
         eStatus = MB_EPORTERR;
     }
diff --git a/apps/modbus/ascii/mbascii.h b/apps/modbus/ascii/mbascii.h
index 47846ddec..1191a1166 100644
--- a/apps/modbus/ascii/mbascii.h
+++ b/apps/modbus/ascii/mbascii.h
@@ -35,7 +35,7 @@
 PR_BEGIN_EXTERN_C
 #endif
 
-#if MB_ASCII_ENABLED > 0
+#ifdef CONFIG_MB_ASCII_ENABLED
 eMBErrorCode    eMBASCIIInit( UCHAR slaveAddress, UCHAR ucPort,
                               ULONG ulBaudRate, eMBParity eParity );
 void            eMBASCIIStart( void );
diff --git a/apps/modbus/functions/mbfunccoils.c b/apps/modbus/functions/mbfunccoils.c
index 54227b335..4bf9ce1ce 100644
--- a/apps/modbus/functions/mbfunccoils.c
+++ b/apps/modbus/functions/mbfunccoils.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
@@ -39,7 +40,6 @@
 #include "mb.h"
 #include "mbframe.h"
 #include "mbproto.h"
-#include "mbconfig.h"
 
 /* ----------------------- Defines ------------------------------------------*/
 #define MB_PDU_FUNC_READ_ADDR_OFF           ( MB_PDU_DATA_OFF )
@@ -63,7 +63,7 @@ eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );
 
 /* ----------------------- Start implementation -----------------------------*/
 
-#if MB_FUNC_READ_COILS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_COILS_ENABLED
 
 eMBException
 eMBFuncReadCoils( UCHAR * pucFrame, USHORT * usLen )
@@ -143,7 +143,7 @@ eMBFuncReadCoils( UCHAR * pucFrame, USHORT * usLen )
     return eStatus;
 }
 
-#if MB_FUNC_WRITE_COIL_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_COIL_ENABLED
 eMBException
 eMBFuncWriteCoil( UCHAR * pucFrame, USHORT * usLen )
 {
@@ -197,7 +197,7 @@ eMBFuncWriteCoil( UCHAR * pucFrame, USHORT * usLen )
 
 #endif
 
-#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED
 eMBException
 eMBFuncWriteMultipleCoils( UCHAR * pucFrame, USHORT * usLen )
 {
diff --git a/apps/modbus/functions/mbfuncdisc.c b/apps/modbus/functions/mbfuncdisc.c
index fb378441b..14d49e470 100644
--- a/apps/modbus/functions/mbfuncdisc.c
+++ b/apps/modbus/functions/mbfuncdisc.c
@@ -17,11 +17,10 @@
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
 
-
-
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
@@ -30,7 +29,6 @@
 #include "mb.h"
 #include "mbframe.h"
 #include "mbproto.h"
-#include "mbconfig.h"
 
 /* ----------------------- Defines ------------------------------------------*/
 #define MB_PDU_FUNC_READ_ADDR_OFF           ( MB_PDU_DATA_OFF )
@@ -43,7 +41,7 @@ eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );
 
 /* ----------------------- Start implementation -----------------------------*/
 
-#if MB_FUNC_READ_COILS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_COILS_ENABLED
 
 eMBException
 eMBFuncReadDiscreteInputs( UCHAR * pucFrame, USHORT * usLen )
diff --git a/apps/modbus/functions/mbfuncholding.c b/apps/modbus/functions/mbfuncholding.c
index e74a0624d..507b7f382 100644
--- a/apps/modbus/functions/mbfuncholding.c
+++ b/apps/modbus/functions/mbfuncholding.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
@@ -39,7 +40,6 @@
 #include "mb.h"
 #include "mbframe.h"
 #include "mbproto.h"
-#include "mbconfig.h"
 
 /* ----------------------- Defines ------------------------------------------*/
 #define MB_PDU_FUNC_READ_ADDR_OFF               ( MB_PDU_DATA_OFF + 0)
@@ -71,7 +71,7 @@ eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );
 
 /* ----------------------- Start implementation -----------------------------*/
 
-#if MB_FUNC_WRITE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_HOLDING_ENABLED
 
 eMBException
 eMBFuncWriteHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
@@ -105,7 +105,7 @@ eMBFuncWriteHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
 }
 #endif
 
-#if MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED
 eMBException
 eMBFuncWriteMultipleHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
 {
@@ -164,7 +164,7 @@ eMBFuncWriteMultipleHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
 }
 #endif
 
-#if MB_FUNC_READ_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_HOLDING_ENABLED
 
 eMBException
 eMBFuncReadHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
@@ -229,7 +229,7 @@ eMBFuncReadHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
 
 #endif
 
-#if MB_FUNC_READWRITE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READWRITE_HOLDING_ENABLED
 
 eMBException
 eMBFuncReadWriteMultipleHoldingRegister( UCHAR * pucFrame, USHORT * usLen )
diff --git a/apps/modbus/functions/mbfuncinput.c b/apps/modbus/functions/mbfuncinput.c
index cceedbafe..92c3ab79f 100644
--- a/apps/modbus/functions/mbfuncinput.c
+++ b/apps/modbus/functions/mbfuncinput.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
@@ -39,7 +40,6 @@
 #include "mb.h"
 #include "mbframe.h"
 #include "mbproto.h"
-#include "mbconfig.h"
 
 /* ----------------------- Defines ------------------------------------------*/
 #define MB_PDU_FUNC_READ_ADDR_OFF           ( MB_PDU_DATA_OFF )
@@ -53,8 +53,8 @@
 eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );
 
 /* ----------------------- Start implementation -----------------------------*/
-#if MB_FUNC_READ_INPUT_ENABLED > 0
 
+#ifdef CONFIG_MB_FUNC_READ_INPUT_ENABLED
 eMBException
 eMBFuncReadInputRegister( UCHAR * pucFrame, USHORT * usLen )
 {
diff --git a/apps/modbus/functions/mbfuncother.c b/apps/modbus/functions/mbfuncother.c
index fcee972bf..5d5636a16 100644
--- a/apps/modbus/functions/mbfuncother.c
+++ b/apps/modbus/functions/mbfuncother.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
@@ -39,12 +40,11 @@
 #include "mb.h"
 #include "mbframe.h"
 #include "mbproto.h"
-#include "mbconfig.h"
 
-#if MB_FUNC_OTHER_REP_SLAVEID_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_OTHER_REP_SLAVEID_ENABLED
 
 /* ----------------------- Static variables ---------------------------------*/
-static UCHAR    ucMBSlaveID[MB_FUNC_OTHER_REP_SLAVEID_BUF];
+static UCHAR    ucMBSlaveID[CONFIG_MB_FUNC_OTHER_REP_SLAVEID_BUF];
 static USHORT   usMBSlaveIDLen;
 
 /* ----------------------- Start implementation -----------------------------*/
@@ -58,7 +58,7 @@ eMBSetSlaveID( UCHAR ucSlaveID, BOOL xIsRunning,
     /* the first byte and second byte in the buffer is reserved for
      * the parameter ucSlaveID and the running flag. The rest of
      * the buffer is available for additional data. */
-    if( usAdditionalLen + 2 < MB_FUNC_OTHER_REP_SLAVEID_BUF )
+    if( usAdditionalLen + 2 < CONFIG_MB_FUNC_OTHER_REP_SLAVEID_BUF )
     {
         usMBSlaveIDLen = 0;
         ucMBSlaveID[usMBSlaveIDLen++] = ucSlaveID;
diff --git a/apps/modbus/functions/mbutils.c b/apps/modbus/functions/mbutils.c
index 6a725703e..8812419ec 100644
--- a/apps/modbus/functions/mbutils.c
+++ b/apps/modbus/functions/mbutils.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
diff --git a/apps/modbus/mb.c b/apps/modbus/mb.c
index e7f372de8..ff773ddca 100644
--- a/apps/modbus/mb.c
+++ b/apps/modbus/mb.c
@@ -29,27 +29,27 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
 
 /* ----------------------- Modbus includes ----------------------------------*/
 #include "mb.h"
-#include "mbconfig.h"
 #include "mbframe.h"
 #include "mbproto.h"
 #include "mbfunc.h"
 
 #include "mbport.h"
-#if MB_RTU_ENABLED == 1
+#ifdef CONFIG_MB_RTU_ENABLED
 #include "mbrtu.h"
 #endif
-#if MB_ASCII_ENABLED == 1
+#ifdef CONFIG_MB_ASCII_ENABLED
 #include "mbascii.h"
 #endif
-#if MB_TCP_ENABLED == 1
+#ifdef CONFIG_MB_TCP_ENABLED
 #include "mbtcp.h"
 #endif
 
@@ -92,35 +92,35 @@ BOOL( *pxMBFrameCBTransmitFSMCur ) ( void );
 /* An array of Modbus functions handlers which associates Modbus function
  * codes with implementing functions.
  */
-static xMBFunctionHandler xFuncHandlers[MB_FUNC_HANDLERS_MAX] = {
-#if MB_FUNC_OTHER_REP_SLAVEID_ENABLED > 0
+static xMBFunctionHandler xFuncHandlers[CONFIG_MB_FUNC_HANDLERS_MAX] = {
+#ifdef CONFIG_MB_FUNC_OTHER_REP_SLAVEID_ENABLED
     {MB_FUNC_OTHER_REPORT_SLAVEID, eMBFuncReportSlaveID},
 #endif
-#if MB_FUNC_READ_INPUT_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_INPUT_ENABLE
     {MB_FUNC_READ_INPUT_REGISTER, eMBFuncReadInputRegister},
 #endif
-#if MB_FUNC_READ_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_HOLDING_ENABLED
     {MB_FUNC_READ_HOLDING_REGISTER, eMBFuncReadHoldingRegister},
 #endif
-#if MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED
     {MB_FUNC_WRITE_MULTIPLE_REGISTERS, eMBFuncWriteMultipleHoldingRegister},
 #endif
-#if MB_FUNC_WRITE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_HOLDING_ENABLED
     {MB_FUNC_WRITE_REGISTER, eMBFuncWriteHoldingRegister},
 #endif
-#if MB_FUNC_READWRITE_HOLDING_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READWRITE_HOLDING_ENABLED
     {MB_FUNC_READWRITE_MULTIPLE_REGISTERS, eMBFuncReadWriteMultipleHoldingRegister},
 #endif
-#if MB_FUNC_READ_COILS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_COILS_ENABLED
     {MB_FUNC_READ_COILS, eMBFuncReadCoils},
 #endif
-#if MB_FUNC_WRITE_COIL_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_COIL_ENABLED
     {MB_FUNC_WRITE_SINGLE_COIL, eMBFuncWriteCoil},
 #endif
-#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED
     {MB_FUNC_WRITE_MULTIPLE_COILS, eMBFuncWriteMultipleCoils},
 #endif
-#if MB_FUNC_READ_DISCRETE_INPUTS_ENABLED > 0
+#ifdef CONFIG_MB_FUNC_READ_DISCRETE_INPUTS_ENABLED
     {MB_FUNC_READ_DISCRETE_INPUTS, eMBFuncReadDiscreteInputs},
 #endif
 };
@@ -143,7 +143,7 @@ eMBInit( eMBMode eMode, UCHAR ucSlaveAddress, UCHAR ucPort, ULONG ulBaudRate, eM
 
         switch ( eMode )
         {
-#if MB_RTU_ENABLED > 0
+#ifdef CONFIG_MB_RTU_ENABLED
         case MB_RTU:
             pvMBFrameStartCur = eMBRTUStart;
             pvMBFrameStopCur = eMBRTUStop;
@@ -157,7 +157,7 @@ eMBInit( eMBMode eMode, UCHAR ucSlaveAddress, UCHAR ucPort, ULONG ulBaudRate, eM
             eStatus = eMBRTUInit( ucMBAddress, ucPort, ulBaudRate, eParity );
             break;
 #endif
-#if MB_ASCII_ENABLED > 0
+#ifdef CONFIG_MB_ASCII_ENABLED 
         case MB_ASCII:
             pvMBFrameStartCur = eMBASCIIStart;
             pvMBFrameStopCur = eMBASCIIStop;
@@ -192,7 +192,7 @@ eMBInit( eMBMode eMode, UCHAR ucSlaveAddress, UCHAR ucPort, ULONG ulBaudRate, eM
     return eStatus;
 }
 
-#if MB_TCP_ENABLED > 0
+#ifdef CONFIG_MB_TCP_ENABLED
 eMBErrorCode
 eMBTCPInit( USHORT ucTCPPort )
 {
@@ -233,7 +233,7 @@ eMBRegisterCB( UCHAR ucFunctionCode, pxMBFunctionHandler pxHandler )
         ENTER_CRITICAL_SECTION(  );
         if( pxHandler != NULL )
         {
-            for( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ )
+            for( i = 0; i < CONFIG_MB_FUNC_HANDLERS_MAX; i++ )
             {
                 if( ( xFuncHandlers[i].pxHandler == NULL ) ||
                     ( xFuncHandlers[i].pxHandler == pxHandler ) )
@@ -243,11 +243,11 @@ eMBRegisterCB( UCHAR ucFunctionCode, pxMBFunctionHandler pxHandler )
                     break;
                 }
             }
-            eStatus = ( i != MB_FUNC_HANDLERS_MAX ) ? MB_ENOERR : MB_ENORES;
+            eStatus = ( i != CONFIG_MB_FUNC_HANDLERS_MAX ) ? MB_ENOERR : MB_ENORES;
         }
         else
         {
-            for( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ )
+            for( i = 0; i < CONFIG_MB_FUNC_HANDLERS_MAX; i++ )
             {
                 if( xFuncHandlers[i].ucFunctionCode == ucFunctionCode )
                 {
@@ -371,7 +371,7 @@ eMBPoll( void )
         case EV_EXECUTE:
             ucFunctionCode = ucMBFrame[MB_PDU_FUNC_OFF];
             eException = MB_EX_ILLEGAL_FUNCTION;
-            for( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ )
+            for( i = 0; i < CONFIG_MB_FUNC_HANDLERS_MAX; i++ )
             {
                 /* No more function handlers registered. Abort. */
                 if( xFuncHandlers[i].ucFunctionCode == 0 )
@@ -396,9 +396,9 @@ eMBPoll( void )
                     ucMBFrame[usLength++] = ( UCHAR )( ucFunctionCode | MB_FUNC_ERROR );
                     ucMBFrame[usLength++] = eException;
                 }
-                if( ( eMBCurrentMode == MB_ASCII ) && MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS )
+                if( ( eMBCurrentMode == MB_ASCII ) && CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS )
                 {
-                    vMBPortTimersDelay( MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS );
+                    vMBPortTimersDelay( CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS );
                 }                
                 eStatus = peMBFrameSendCur( ucMBAddress, ucMBFrame, usLength );
             }
diff --git a/apps/modbus/nuttx/port.h b/apps/modbus/nuttx/port.h
new file mode 100644
index 000000000..4102628b4
--- /dev/null
+++ b/apps/modbus/nuttx/port.h
@@ -0,0 +1,75 @@
+/*
+ * FreeModbus Libary: Linux Port
+ * Copyright (C) 2006 Christian Walter <wolti@sil.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * File: $Id: port.h,v 1.1 2006/08/01 20:58:49 wolti Exp $
+ */
+
+#ifndef _PORT_H
+#define _PORT_H
+
+#include <assert.h>
+
+#define INLINE
+#define PR_BEGIN_EXTERN_C           extern "C" {
+#define PR_END_EXTERN_C             }
+
+#ifdef __cplusplus
+PR_BEGIN_EXTERN_C
+#endif
+/* ----------------------- Defines ------------------------------------------*/
+#define ENTER_CRITICAL_SECTION( ) vMBPortEnterCritical()
+#define EXIT_CRITICAL_SECTION( ) vMBPortExitCritical()
+#define MB_PORT_HAS_CLOSE   1
+#ifndef TRUE
+#define TRUE            1
+#endif
+#ifndef FALSE
+#define FALSE           0
+#endif
+/* ----------------------- Type definitions ---------------------------------*/
+    typedef enum
+{
+    MB_LOG_ERROR = 0,
+    MB_LOG_WARN = 1,
+    MB_LOG_INFO = 2,
+    MB_LOG_DEBUG = 3
+} eMBPortLogLevel;
+
+typedef char    BOOL;
+typedef unsigned char UCHAR;
+typedef char    CHAR;
+typedef unsigned short USHORT;
+typedef short   SHORT;
+
+typedef unsigned long ULONG;
+typedef long    LONG;
+
+/* ----------------------- Function prototypes ------------------------------*/
+
+void            vMBPortEnterCritical( void );
+void            vMBPortExitCritical( void );
+void            vMBPortLog( eMBPortLogLevel eLevel, const CHAR * szModule,
+                            const CHAR * szFmt, ... );
+void            vMBPortTimerPoll(  );
+BOOL            xMBPortSerialPoll(  );
+BOOL            xMBPortSerialSetTimeout( ULONG dwTimeoutMs );
+
+#ifdef __cplusplus
+PR_END_EXTERN_C
+#endif
+#endif
diff --git a/apps/modbus/nuttx/portevent.c b/apps/modbus/nuttx/portevent.c
new file mode 100644
index 000000000..dd7a6fef8
--- /dev/null
+++ b/apps/modbus/nuttx/portevent.c
@@ -0,0 +1,72 @@
+/*
+ * FreeModbus Libary: Linux Port
+ * Copyright (C) 2006 Christian Walter <wolti@sil.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * File: $Id: portevent.c,v 1.1 2006/08/01 20:58:49 wolti Exp $
+ */
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbport.h"
+
+/* ----------------------- Variables ----------------------------------------*/
+static eMBEventType eQueuedEvent;
+static BOOL     xEventInQueue;
+
+/* ----------------------- Start implementation -----------------------------*/
+BOOL
+xMBPortEventInit( void )
+{
+    xEventInQueue = FALSE;
+    return TRUE;
+}
+
+BOOL
+xMBPortEventPost( eMBEventType eEvent )
+{
+    xEventInQueue = TRUE;
+    eQueuedEvent = eEvent;
+    return TRUE;
+}
+
+BOOL
+xMBPortEventGet( eMBEventType * eEvent )
+{
+    BOOL            xEventHappened = FALSE;
+
+    if( xEventInQueue )
+    {
+        *eEvent = eQueuedEvent;
+        xEventInQueue = FALSE;
+        xEventHappened = TRUE;
+    }
+    else
+    {
+        /* Poll the serial device. The serial device timeouts if no
+         * characters have been received within for t3.5 during an
+         * active transmission or if nothing happens within a specified
+         * amount of time. Both timeouts are configured from the timer
+         * init functions.
+         */
+        ( void )xMBPortSerialPoll(  );
+
+        /* Check if any of the timers have expired. */
+        vMBPortTimerPoll(  );
+
+    }
+    return xEventHappened;
+}
diff --git a/apps/modbus/nuttx/portother.c b/apps/modbus/nuttx/portother.c
new file mode 100644
index 000000000..bb7068940
--- /dev/null
+++ b/apps/modbus/nuttx/portother.c
@@ -0,0 +1,102 @@
+/*
+ * FreeModbus Libary: Linux Port
+ * Copyright (C) 2006 Christian Walter <wolti@sil.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * File: $Id: portother.c,v 1.1 2006/08/01 20:58:49 wolti Exp $
+ */
+
+/* ----------------------- Standard includes --------------------------------*/
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include "port.h"
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbport.h"
+
+/* ----------------------- Defines ------------------------------------------*/
+#define NELEMS( x ) ( sizeof( ( x ) )/sizeof( ( x )[0] ) )
+
+/* ----------------------- Static variables ---------------------------------*/
+static FILE    *fLogFile = NULL;
+static eMBPortLogLevel eLevelMax = MB_LOG_DEBUG;
+static pthread_mutex_t xLock = PTHREAD_MUTEX_INITIALIZER;
+
+/* ----------------------- Start implementation -----------------------------*/
+void
+vMBPortLogLevel( eMBPortLogLevel eNewLevelMax )
+{
+    eLevelMax = eNewLevelMax;
+}
+
+void
+vMBPortLogFile( FILE * fNewLogFile )
+{
+    fLogFile = fNewLogFile;
+}
+
+void
+vMBPortLog( eMBPortLogLevel eLevel, const CHAR * szModule, const CHAR * szFmt, ... )
+{
+    CHAR            szBuf[512];
+    int             i;
+    va_list         args;
+    FILE           *fOutput = fLogFile == NULL ? stderr : fLogFile;
+
+    static const char *arszLevel2Str[] = { "ERROR", "WARN", "INFO", "DEBUG" };
+
+    i = snprintf( szBuf, NELEMS( szBuf ), "%s: %s: ", arszLevel2Str[eLevel], szModule );
+
+    if( i != 0 )
+    {
+        va_start( args, szFmt );
+        i += vsnprintf( &szBuf[i], NELEMS( szBuf ) - i, szFmt, args );
+        va_end( args );
+    }
+
+    if( i != 0 )
+    {
+        if( eLevel <= eLevelMax )
+        {
+            fputs( szBuf, fOutput );
+        }
+    }
+}
+
+void
+vMBPortEnterCritical( void )
+{
+    if( pthread_mutex_lock( &xLock ) != 0 )
+    {
+        vMBPortLog( MB_LOG_ERROR, "OTHER", "Locking primitive failed: %s\n", strerror( errno ) );
+    }
+}
+
+void
+vMBPortExitCritical( void )
+{
+    if( pthread_mutex_unlock( &xLock ) != 0 )
+    {
+        vMBPortLog( MB_LOG_ERROR, "OTHER", "Locking primitive failed: %s\n", strerror( errno ) );
+    }
+}
diff --git a/apps/modbus/nuttx/portserial.c b/apps/modbus/nuttx/portserial.c
new file mode 100644
index 000000000..bacab6a23
--- /dev/null
+++ b/apps/modbus/nuttx/portserial.c
@@ -0,0 +1,352 @@
+/*
+ * FreeModbus Libary: Linux Port
+ * Copyright (C) 2006 Christian Walter <wolti@sil.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * File: $Id: portserial.c,v 1.3 2006/10/12 08:35:34 wolti Exp $
+ */
+
+/* ----------------------- Standard includes --------------------------------*/
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/select.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "port.h"
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbport.h"
+
+/* ----------------------- Defines  -----------------------------------------*/
+#ifdef CONFIG_MB_ASCII_ENABLED
+#define BUF_SIZE    513         /* must hold a complete ASCII frame. */
+#else
+#define BUF_SIZE    256         /* must hold a complete RTU frame. */
+#endif
+
+/* ----------------------- Static variables ---------------------------------*/
+static int      iSerialFd = -1;
+static BOOL     bRxEnabled;
+static BOOL     bTxEnabled;
+
+static ULONG    ulTimeoutMs;
+static UCHAR    ucBuffer[BUF_SIZE];
+static int      uiRxBufferPos;
+static int      uiTxBufferPos;
+
+static struct termios xOldTIO;
+
+/* ----------------------- Function prototypes ------------------------------*/
+static BOOL     prvbMBPortSerialRead( UCHAR * pucBuffer, USHORT usNBytes, USHORT * usNBytesRead );
+static BOOL     prvbMBPortSerialWrite( UCHAR * pucBuffer, USHORT usNBytes );
+
+/* ----------------------- Begin implementation -----------------------------*/
+void
+vMBPortSerialEnable( BOOL bEnableRx, BOOL bEnableTx )
+{
+    /* it is not allowed that both receiver and transmitter are enabled. */
+    assert( !bEnableRx || !bEnableTx );
+
+    if( bEnableRx )
+    {
+        ( void )tcflush( iSerialFd, TCIFLUSH );
+        uiRxBufferPos = 0;
+        bRxEnabled = TRUE;
+    }
+    else
+    {
+        bRxEnabled = FALSE;
+    }
+    if( bEnableTx )
+    {
+        bTxEnabled = TRUE;
+        uiTxBufferPos = 0;
+    }
+    else
+    {
+        bTxEnabled = FALSE;
+    }
+}
+
+BOOL
+xMBPortSerialInit( UCHAR ucPort, ULONG ulBaudRate, UCHAR ucDataBits, eMBParity eParity )
+{
+    CHAR            szDevice[16];
+    BOOL            bStatus = TRUE;
+
+    struct termios  xNewTIO;
+    speed_t         xNewSpeed;
+
+    snprintf( szDevice, 16, "/dev/ttyS%d", ucPort );
+
+    if( ( iSerialFd = open( szDevice, O_RDWR | O_NOCTTY ) ) < 0 )
+    {
+        vMBPortLog( MB_LOG_ERROR, "SER-INIT", "Can't open serial port %s: %s\n", szDevice,
+                    strerror( errno ) );
+    }
+    else if( tcgetattr( iSerialFd, &xOldTIO ) != 0 )
+    {
+        vMBPortLog( MB_LOG_ERROR, "SER-INIT", "Can't get settings from port %s: %s\n", szDevice,
+                    strerror( errno ) );
+    }
+    else
+    {
+        bzero( &xNewTIO, sizeof( struct termios ) );
+
+        xNewTIO.c_iflag |= IGNBRK | INPCK;
+        xNewTIO.c_cflag |= CREAD | CLOCAL;
+        switch ( eParity )
+        {
+        case MB_PAR_NONE:
+            break;
+        case MB_PAR_EVEN:
+            xNewTIO.c_cflag |= PARENB;
+            break;
+        case MB_PAR_ODD:
+            xNewTIO.c_cflag |= PARENB | PARODD;
+            break;
+        default:
+            bStatus = FALSE;
+        }
+        switch ( ucDataBits )
+        {
+        case 8:
+            xNewTIO.c_cflag |= CS8;
+            break;
+        case 7:
+            xNewTIO.c_cflag |= CS7;
+            break;
+        default:
+            bStatus = FALSE;
+        }
+        switch ( ulBaudRate )
+        {
+        case 9600:
+            xNewSpeed = B9600;
+            break;
+        case 19200:
+            xNewSpeed = B19200;
+            break;
+        case 38400:
+            xNewSpeed = B38400;
+            break;
+        case 57600:
+            xNewSpeed = B57600;
+            break;
+        case 115200:
+            xNewSpeed = B115200;
+            break;
+        default:
+            bStatus = FALSE;
+        }
+        if( bStatus )
+        {
+            if( cfsetispeed( &xNewTIO, xNewSpeed ) != 0 )
+            {
+                vMBPortLog( MB_LOG_ERROR, "SER-INIT", "Can't set baud rate %ld for port %s: %s\n",
+                            ulBaudRate, strerror( errno ) );
+            }
+            else if( cfsetospeed( &xNewTIO, xNewSpeed ) != 0 )
+            {
+                vMBPortLog( MB_LOG_ERROR, "SER-INIT", "Can't set baud rate %ld for port %s: %s\n",
+                            ulBaudRate, szDevice, strerror( errno ) );
+            }
+            else if( tcsetattr( iSerialFd, TCSANOW, &xNewTIO ) != 0 )
+            {
+                vMBPortLog( MB_LOG_ERROR, "SER-INIT", "Can't set settings for port %s: %s\n",
+                            szDevice, strerror( errno ) );
+            }
+            else
+            {
+                vMBPortSerialEnable( FALSE, FALSE );
+                bStatus = TRUE;
+            }
+        }
+    }
+    return bStatus;
+}
+
+BOOL
+xMBPortSerialSetTimeout( ULONG ulNewTimeoutMs )
+{
+    if( ulNewTimeoutMs > 0 )
+    {
+        ulTimeoutMs = ulNewTimeoutMs;
+    }
+    else
+    {
+        ulTimeoutMs = 1;
+    }
+    return TRUE;
+}
+
+void
+vMBPortClose( void )
+{
+    if( iSerialFd != -1 )
+    {
+        ( void )tcsetattr( iSerialFd, TCSANOW, &xOldTIO );
+        ( void )close( iSerialFd );
+        iSerialFd = -1;
+    }
+}
+
+BOOL
+prvbMBPortSerialRead( UCHAR * pucBuffer, USHORT usNBytes, USHORT * usNBytesRead )
+{
+    BOOL            bResult = TRUE;
+    ssize_t         res;
+    fd_set          rfds;
+    struct timeval  tv;
+
+    tv.tv_sec = 0;
+    tv.tv_usec = 50000;
+    FD_ZERO( &rfds );
+    FD_SET( iSerialFd, &rfds );
+
+    /* Wait until character received or timeout. Recover in case of an
+     * interrupted read system call. */
+    do
+    {
+        if( select( iSerialFd + 1, &rfds, NULL, NULL, &tv ) == -1 )
+        {
+            if( errno != EINTR )
+            {
+                bResult = FALSE;
+            }
+        }
+        else if( FD_ISSET( iSerialFd, &rfds ) )
+        {
+            if( ( res = read( iSerialFd, pucBuffer, usNBytes ) ) == -1 )
+            {
+                bResult = FALSE;
+            }
+            else
+            {
+                *usNBytesRead = ( USHORT ) res;
+                break;
+            }
+        }
+        else
+        {
+            *usNBytesRead = 0;
+            break;
+        }
+    }
+    while( bResult == TRUE );
+    return bResult;
+}
+
+BOOL
+prvbMBPortSerialWrite( UCHAR * pucBuffer, USHORT usNBytes )
+{
+    ssize_t         res;
+    size_t          left = ( size_t ) usNBytes;
+    size_t          done = 0;
+
+    while( left > 0 )
+    {
+        if( ( res = write( iSerialFd, pucBuffer + done, left ) ) == -1 )
+        {
+            if( errno != EINTR )
+            {
+                break;
+            }
+            /* call write again because of interrupted system call. */
+            continue;
+        }
+        done += res;
+        left -= res;
+    }
+    return left == 0 ? TRUE : FALSE;
+}
+
+BOOL
+xMBPortSerialPoll(  )
+{
+    BOOL            bStatus = TRUE;
+    USHORT          usBytesRead;
+    int             i;
+
+    while( bRxEnabled )
+    {
+        if( prvbMBPortSerialRead( &ucBuffer[0], BUF_SIZE, &usBytesRead ) )
+        {
+            if( usBytesRead == 0 )
+            {
+                /* timeout with no bytes. */
+                break;
+            }
+            else if( usBytesRead > 0 )
+            {
+                for( i = 0; i < usBytesRead; i++ )
+                {
+                    /* Call the modbus stack and let him fill the buffers. */
+                    ( void )pxMBFrameCBByteReceived(  );
+                }
+                uiRxBufferPos = 0;
+            }
+        }
+        else
+        {
+            vMBPortLog( MB_LOG_ERROR, "SER-POLL", "read failed on serial device: %s\n",
+                        strerror( errno ) );
+            bStatus = FALSE;
+        }
+    }
+    if( bTxEnabled )
+    {
+        while( bTxEnabled )
+        {
+            ( void )pxMBFrameCBTransmitterEmpty(  );
+            /* Call the modbus stack to let him fill the buffer. */
+        }
+        if( !prvbMBPortSerialWrite( &ucBuffer[0], uiTxBufferPos ) )
+        {
+            vMBPortLog( MB_LOG_ERROR, "SER-POLL", "write failed on serial device: %s\n",
+                        strerror( errno ) );
+            bStatus = FALSE;
+        }
+    }
+
+    return bStatus;
+}
+
+BOOL
+xMBPortSerialPutByte( CHAR ucByte )
+{
+    assert( uiTxBufferPos < BUF_SIZE );
+    ucBuffer[uiTxBufferPos] = ucByte;
+    uiTxBufferPos++;
+    return TRUE;
+}
+
+BOOL
+xMBPortSerialGetByte( CHAR * pucByte )
+{
+    assert( uiRxBufferPos < BUF_SIZE );
+    *pucByte = ucBuffer[uiRxBufferPos];
+    uiRxBufferPos++;
+    return TRUE;
+}
diff --git a/apps/modbus/nuttx/porttimer.c b/apps/modbus/nuttx/porttimer.c
new file mode 100644
index 000000000..c440e4f1f
--- /dev/null
+++ b/apps/modbus/nuttx/porttimer.c
@@ -0,0 +1,98 @@
+/*
+ * FreeModbus Libary: Linux Port
+ * Copyright (C) 2006 Christian Walter <wolti@sil.at>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * File: $Id: porttimer.c,v 1.1 2006/08/01 20:58:50 wolti Exp $
+ */
+
+/* ----------------------- Standard includes --------------------------------*/
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+#include "port.h"
+
+/* ----------------------- Modbus includes ----------------------------------*/
+#include "mb.h"
+#include "mbport.h"
+
+/* ----------------------- Defines ------------------------------------------*/
+
+/* ----------------------- Static variables ---------------------------------*/
+ULONG           ulTimeOut;
+BOOL            bTimeoutEnable;
+
+static struct timeval xTimeLast;
+
+/* ----------------------- Start implementation -----------------------------*/
+BOOL
+xMBPortTimersInit( USHORT usTim1Timerout50us )
+{
+    ulTimeOut = usTim1Timerout50us / 20U;
+    if( ulTimeOut == 0 )
+        ulTimeOut = 1;
+
+    return xMBPortSerialSetTimeout( ulTimeOut );
+}
+
+void
+xMBPortTimersClose(  )
+{
+    /* Does not use any hardware resources. */
+}
+
+void
+vMBPortTimerPoll(  )
+{
+    ULONG           ulDeltaMS;
+    struct timeval  xTimeCur;
+
+    /* Timers are called from the serial layer because we have no high
+     * res timer in Win32. */
+    if( bTimeoutEnable )
+    {
+        if( gettimeofday( &xTimeCur, NULL ) != 0 )
+        {
+            /* gettimeofday failed - retry next time. */
+        }
+        else
+        {
+            ulDeltaMS = ( xTimeCur.tv_sec - xTimeLast.tv_sec ) * 1000L +
+                ( xTimeCur.tv_usec - xTimeLast.tv_usec ) * 1000L;
+            if( ulDeltaMS > ulTimeOut )
+            {
+                bTimeoutEnable = FALSE;
+                ( void )pxMBPortCBTimerExpired(  );
+            }
+        }
+    }
+}
+
+void
+vMBPortTimersEnable(  )
+{
+    int             res = gettimeofday( &xTimeLast, NULL );
+
+    assert( res == 0 );
+    bTimeoutEnable = TRUE;
+}
+
+void
+vMBPortTimersDisable(  )
+{
+    bTimeoutEnable = FALSE;
+}
diff --git a/apps/modbus/rtu/mbrtu.c b/apps/modbus/rtu/mbrtu.c
index fc9b854ff..d3fd01fcb 100644
--- a/apps/modbus/rtu/mbrtu.c
+++ b/apps/modbus/rtu/mbrtu.c
@@ -29,8 +29,9 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
diff --git a/apps/modbus/tcp/mbtcp.c b/apps/modbus/tcp/mbtcp.c
index fb06144ae..a666c17a5 100644
--- a/apps/modbus/tcp/mbtcp.c
+++ b/apps/modbus/tcp/mbtcp.c
@@ -29,20 +29,20 @@
  */
 
 /* ----------------------- System includes ----------------------------------*/
-#include "stdlib.h"
-#include "string.h"
+#include <nuttx/config.h>
+#include <stdlib.h>
+#include <string.h>
 
 /* ----------------------- Platform includes --------------------------------*/
 #include "port.h"
 
 /* ----------------------- Modbus includes ----------------------------------*/
 #include "mb.h"
-#include "mbconfig.h"
 #include "mbtcp.h"
 #include "mbframe.h"
 #include "mbport.h"
 
-#if MB_TCP_ENABLED > 0
+#ifdef CONFIG_MB_TCP_ENABLED
 
 /* ----------------------- Defines ------------------------------------------*/