diff --git a/hardware/arduino/avr/cores/arduino/USBCore.cpp b/hardware/arduino/avr/cores/arduino/USBCore.cpp
index 398bc73ee..4c71b34d4 100644
--- a/hardware/arduino/avr/cores/arduino/USBCore.cpp
+++ b/hardware/arduino/avr/cores/arduino/USBCore.cpp
@@ -230,7 +230,7 @@ int USB_Recv(u8 ep, void* d, int len)
 	n = len;
 	u8* dst = (u8*)d;
 	while (n--)
-		*dst++ = Recv8();
+		*dst++ = USBD_Recv8();
 	if (len && !FifoByteCount())	// release empty buffer
 		ReleaseRX();
 	
diff --git a/hardware/arduino/sam/cores/sam/USBAPI.h b/hardware/arduino/sam/cores/sam/USBAPI.h
index 6d0e51447..a00599e32 100644
--- a/hardware/arduino/sam/cores/sam/USBAPI.h
+++ b/hardware/arduino/sam/cores/sam/USBAPI.h
@@ -43,10 +43,10 @@ extern Serial_ Serial;
 //================================================================================
 //	Mouse
 
-#define MOUSE_LEFT 1
-#define MOUSE_RIGHT 2
-#define MOUSE_MIDDLE 4
-#define MOUSE_ALL (MOUSE_LEFT | MOUSE_RIGHT | MOUSE_MIDDLE)
+#define MOUSE_LEFT    (1u)
+#define MOUSE_RIGHT   (2u)
+#define MOUSE_MIDDLE  (4u)
+#define MOUSE_ALL     (MOUSE_LEFT | MOUSE_RIGHT | MOUSE_MIDDLE)
 
 class Mouse_
 {
@@ -67,14 +67,14 @@ extern Mouse_ Mouse;
 //================================================================================
 //	Keyboard
 
-#define KEY_MODIFIER_LEFT_CTRL		0x01
-#define KEY_MODIFIER_LEFT_SHIFT		0x02
-#define KEY_MODIFIER_LEFT_ALT		0x04
-#define KEY_MODIFIER_LEFT_GUI		0x08
-#define KEY_MODIFIER_RIGHT_CTRL		0x010
-#define KEY_MODIFIER_RIGHT_SHIFT	0x020
-#define KEY_MODIFIER_RIGHT_ALT		0x040
-#define KEY_MODIFIER_RIGHT_GUI		0x080
+#define KEY_MODIFIER_LEFT_CTRL		(0x01u)
+#define KEY_MODIFIER_LEFT_SHIFT		(0x02u)
+#define KEY_MODIFIER_LEFT_ALT		  (0x04u)
+#define KEY_MODIFIER_LEFT_GUI		  (0x08u)
+#define KEY_MODIFIER_RIGHT_CTRL		(0x010u)
+#define KEY_MODIFIER_RIGHT_SHIFT	(0x020u)
+#define KEY_MODIFIER_RIGHT_ALT		(0x040u)
+#define KEY_MODIFIER_RIGHT_GUI		(0x080u)
 
 //	Low level key report: up to 6 keys and shift, ctrl etc at once
 typedef struct
@@ -148,10 +148,6 @@ bool	CDC_Setup(Setup& setup);
 //================================================================================
 //================================================================================
 
-#define TRANSFER_PGM		0x80
-#define TRANSFER_RELEASE	0x40
-#define TRANSFER_ZERO		0x20
-
 int USB_SendControl(uint8_t flags, const void* d, int len);
 int USB_RecvControl(void* d, int len);
 
diff --git a/hardware/arduino/sam/cores/sam/USBCore.cpp b/hardware/arduino/sam/cores/sam/USBCore.cpp
index aedeeb760..f4587e97f 100644
--- a/hardware/arduino/sam/cores/sam/USBCore.cpp
+++ b/hardware/arduino/sam/cores/sam/USBCore.cpp
@@ -25,10 +25,8 @@
 
 #if defined(USBCON)
 
-
-
-extern const u8 _initEndpoints[] ;
-const u8 _initEndpoints[] =
+extern const uint8_t _initEndpoints[] ;
+const uint8_t _initEndpoints[] =
 {
 	0,
 
@@ -45,37 +43,37 @@ const u8 _initEndpoints[] =
 
 /** Pulse generation counters to keep track of the number of milliseconds remaining for each pulse type */
 #define TX_RX_LED_PULSE_MS 100
-volatile u8 TxLEDPulse; /**< Milliseconds remaining for data Tx LED pulse */
-volatile u8 RxLEDPulse; /**< Milliseconds remaining for data Rx LED pulse */
+volatile uint8_t TxLEDPulse; /**< Milliseconds remaining for data Tx LED pulse */
+volatile uint8_t RxLEDPulse; /**< Milliseconds remaining for data Rx LED pulse */
 
 //==================================================================
 //==================================================================
 
-extern const u16 STRING_LANGUAGE[] ;
-extern const u16 STRING_IPRODUCT[] ;
-extern const u16 STRING_IMANUFACTURER[] ;
+extern const uint16_t STRING_LANGUAGE[] ;
+extern const uint16_t STRING_IPRODUCT[] ;
+extern const uint16_t STRING_IMANUFACTURER[] ;
 extern const DeviceDescriptor USB_DeviceDescriptor ;
 extern const DeviceDescriptor USB_DeviceDescriptorA ;
 
-const u16 STRING_LANGUAGE[2] = {
+const uint16_t STRING_LANGUAGE[2] = {
 	(3<<8) | (2+2),
 	0x0409	// English
 };
 
-const u16 STRING_IPRODUCT[17] = {
+const uint16_t STRING_IPRODUCT[17] = {
 	(3<<8) | (2+2*16),
 #if USB_PID == USB_PID_LEONARDO
 	'A','r','d','u','i','n','o',' ','L','e','o','n','a','r','d','o'
 #elif USB_PID == USB_PID_MICRO
 	'A','r','d','u','i','n','o',' ','M','i','c','r','o',' ',' ',' '
-#elif USB_PID == ARDUINO_MODEL_USB_PID
+#elif USB_PID == USB_PID_DUE
 	'A','r','d','u','i','n','o',' ','D','u','e',' ',' ',' ',' ',' '
 #else
 #error "Need an USB PID"
 #endif
 };
 
-const u16 STRING_IMANUFACTURER[12] = {
+const uint16_t STRING_IMANUFACTURER[12] = {
 	(3<<8) | (2+2*11),
 	'A','r','d','u','i','n','o',' ','L','L','C'
 };
@@ -96,63 +94,140 @@ const DeviceDescriptor USB_DeviceDescriptorA =
 //==================================================================
 //==================================================================
 
-volatile u8 _usbConfiguration = 0;
+volatile uint8_t _usbConfiguration = 0;
+uint8_t _cdcComposite = 0;
+
 
 //==================================================================
 //==================================================================
 
-static
-bool SendControl(u8 d)
+//	Recv 1 byte if ready
+int USBD_Recv(uint8_t ep)
 {
-	if (_cmark < _cend)
+	uint8_t c;
+
+	if (USB_Recv(ep,&c,1) != 1)
+  {
+		return -1;
+  }
+  else
+  {
+	  return c;
+  }
+}
+
+//	Non Blocking receive
+//	Return number of bytes read
+int USBD_Recv(uint8_t ep, void* d, int len)
+{
+  uint8_t n ;
+	uint8_t* dst ;
+
+	if (!_usbConfiguration || len < 0)
+  {
+		return -1;
+  }
+
+	n = FifoByteCount(ep);
+  
+	len = min(n,len);
+	n = len;
+	dst = (uint8_t*)d;
+	while (n--)
+  {
+		*dst++ = Recv8(ep);
+  }
+//	if (len && !FifoByteCount())	// release empty buffer
+//		ReleaseRX();
+
+	return len;
+}
+
+static bool USBD_SendControl(uint8_t d)
+{
+	if ( _cmark < _cend )
 	{
-		if (!WaitForINOrOUT())
+		if ( !WaitForINOrOUT() )
+    {
 			return false;
-		Send8(d);
-		if (!((_cmark + 1) & 0x3F))
+    }
+      
+		Send8( d ) ;
+    
+		if ( !((_cmark + 1) & 0x3F) )
+    {
 			ClearIN();	// Fifo is full, release this packet
+    }
 	}
 	_cmark++;
-	return true;
-};
+  
+	return true ;
+}
 
 //	Clipped by _cmark/_cend
-int USB_SendControl(u8 flags, const void* d, int len)
+int USBD_SendControl(uint8_t flags, const void* d, int len)
 {
 	int sent = len;
-	const u8* data = (const u8*)d;
-	bool pgm = flags & TRANSFER_PGM;
-	while (len--)
+	const uint8_t* data = (const uint8_t*)d ;
+
+	while ( len-- )
 	{
-		u8 c = pgm ? *data++ : *data++;
-		if (!SendControl(c))
+		uint8_t c = *data++ ;
+    
+		if ( !SendControl( c ) )
+    {
 			return -1;
+    }
 	}
+
 	return sent;
 }
 
 //	Does not timeout or cross fifo boundaries
 //	Will only work for transfers <= 64 bytes
 //	TODO
-int USB_RecvControl(void* d, int len)
+int USBD_RecvControl(void* d, int len)
 {
-	WaitOUT();
-	Recv((u8*)d,len);
-	ClearOUT();
-	return len;
+	WaitOUT() ;
+	Recv( (uint8_t*)d, len ) ;
+	ClearOUT() ;
+
+	return len ;
 }
 
-int SendInterfaces()
+//	Handle CLASS_INTERFACE requests
+bool USBD_ClassInterfaceRequest(Setup& setup)
 {
-	int total = 0;
-	u8 interfaces = 0;
+	uint8_t i = setup.wIndex;
 
 #ifdef CDC_ENABLED
-	total = CDC_GetInterface(&interfaces);
+	if ( CDC_ACM_INTERFACE == i )
+  {
+		return CDC_Setup(setup);
+  }
 #endif
 
 #ifdef HID_ENABLED
-	total += HID_GetInterface(&interfaces);
+	if ( HID_INTERFACE == i )
+  {
+		return HID_Setup(setup);
+  }
+#endif
+
+	return false ;
+}
+
+int USBD_SendInterfaces(void)
+{
+	int total = 0;
+	uint8_t interfaces = 0;
+
+#ifdef CDC_ENABLED
+	total = CDC_GetInterface(&interfaces) ;
+#endif
+
+#ifdef HID_ENABLED
+	total += HID_GetInterface(&interfaces) ;
 #endif
 
 	return interfaces;
@@ -161,8 +236,7 @@ int SendInterfaces()
 //	Construct a dynamic configuration descriptor
 //	This really needs dynamic endpoint allocation etc
 //	TODO
-static
-bool SendConfiguration(int maxlen)
+static bool USBD_SendConfiguration(int maxlen)
 {
 	//	Count and measure interfaces
 	InitControl(0);
@@ -176,73 +250,89 @@ bool SendConfiguration(int maxlen)
 	return true;
 }
 
-u8 _cdcComposite = 0;
-
-static
-bool SendDescriptor(Setup& setup)
+static bool USBD_SendDescriptor(Setup& setup)
 {
-	u8 t = setup.wValueH;
-	if (USB_CONFIGURATION_DESCRIPTOR_TYPE == t)
+	uint8_t t = setup.wValueH;
+	uint8_t desc_length = 0;
+	const uint8_t* desc_addr = 0;
+
+	if ( USB_CONFIGURATION_DESCRIPTOR_TYPE == t )
+  {
 		return SendConfiguration(setup.wLength);
+  }
 
 	InitControl(setup.wLength);
 #ifdef HID_ENABLED
-	if (HID_REPORT_DESCRIPTOR_TYPE == t)
-		return HID_GetDescriptor(t);
+	if ( HID_REPORT_DESCRIPTOR_TYPE == t )
+  {
+		return HID_GetDescriptor( t ) ;
+  }
 #endif
 
-	u8 desc_length = 0;
-	const u8* desc_addr = 0;
 	if (USB_DEVICE_DESCRIPTOR_TYPE == t)
 	{
-		if (setup.wLength == 8)
+		if ( setup.wLength == 8 )
+    {
 			_cdcComposite = 1;
-		desc_addr = _cdcComposite ?  (const u8*)&USB_DeviceDescriptorA : (const u8*)&USB_DeviceDescriptor;
+    }
+		desc_addr = _cdcComposite ?  (const uint8_t*)&USB_DeviceDescriptorA : (const uint8_t*)&USB_DeviceDescriptor;
 	}
 	else if (USB_STRING_DESCRIPTOR_TYPE == t)
 	{
 		if (setup.wValueL == 0)
-			desc_addr = (const u8*)&STRING_LANGUAGE;
+			desc_addr = (const uint8_t*)&STRING_LANGUAGE;
 		else if (setup.wValueL == IPRODUCT)
-			desc_addr = (const u8*)&STRING_IPRODUCT;
+			desc_addr = (const uint8_t*)&STRING_IPRODUCT;
 		else if (setup.wValueL == IMANUFACTURER)
-			desc_addr = (const u8*)&STRING_IMANUFACTURER;
+			desc_addr = (const uint8_t*)&STRING_IMANUFACTURER;
 		else
 			return false;
 	}
 
-	if (desc_addr == 0)
-		return false;
-	if (desc_length == 0)
+	if ( desc_addr == 0 )
+  {
+		return false ;
+  }
+  
+	if ( desc_length == 0 )
+  {
 		desc_length = *desc_addr;
+  }
 
 	USB_SendControl(TRANSFER_PGM,desc_addr,desc_length);
+
 	return true;
 }
 
 //	Endpoint 0 interrupt
-//ISR(USB_COM_vect)
 void USB_ISR()
 {
-    SetEP(0);
-	if (!ReceivedSetupInt())
+  SetEP(0) ;
+  
+	if ( !ReceivedSetupInt() )
+  {
 		return;
+  }
 
-	Setup setup;
-	Recv((u8*)&setup,8);
+	Setup setup ;
+	Recv((uint8_t*)&setup,8);
 	ClearSetupInt();
 
-	u8 requestType = setup.bmRequestType;
+	uint8_t requestType = setup.bmRequestType;
 	if (requestType & REQUEST_DEVICETOHOST)
+  {
 		WaitIN();
+  }
 	else
+  {
 		ClearIN();
+  }
 
-    bool ok = true;
+  bool ok = true ;
 	if (REQUEST_STANDARD == (requestType & REQUEST_TYPE))
 	{
 		//	Standard Requests
-		u8 r = setup.bRequest;
+		uint8_t r = setup.bRequest;
 		if (GET_STATUS == r)
 		{
 			Send8(0);		// TODO
@@ -277,8 +367,11 @@ void USB_ISR()
 			{
 				InitEndpoints();
 				_usbConfiguration = setup.wValueL;
-			} else
+			} 
+      else
+      {
 				ok = false;
+      }
 		}
 		else if (GET_INTERFACE == r)
 		{
@@ -294,14 +387,16 @@ void USB_ISR()
 	}
 
 	if (ok)
+  {
 		ClearIN();
+  }
 	else
 	{
 		Stall();
 	}
 }
 
-void USB_Flush(u8 ep)
+void USBD_Flush(uint8_t ep)
 {
 	SetEP(ep);
 //	if (FifoByteCount())
@@ -316,7 +411,7 @@ void USB_Flush(u8 ep)
 //  General interrupt
 ISR(USB_GEN_vect)
 {
-    u8 udint = UDINT;
+    uint8_t udint = UDINT;
     UDINT = 0;
 
     //  End of Reset
@@ -348,9 +443,9 @@ ISR(USB_GEN_vect)
 
 //	VBUS or counting frames
 //	Any frame counting?
-u8 USBConnected()
+uint8_t USBD_Connected(void)
 {
-	u8 f = UDFNUML;
+	uint8_t f = UDFNUML;
 	delay(3);
 	return f != UDFNUML;
 }
@@ -365,51 +460,12 @@ USB_::USB_()
 {
 }
 
-void USB_::attach()
-{/*
-	_usbConfiguration = 0;
+void USB_::attach(void)
+{
+  USBD_Attach() ;
+}
 
-	//UHWCON = 0x01;						// power internal reg
-	//USBCON = (1<<USBE)|(1<<FRZCLK);		// clock frozen, usb enabled
-	//PLLCSR = 0x12;						// Need 16 MHz xtal
-	//while (!(PLLCSR & (1<<PLOCK)))		// wait for lock pll
-	//	;
-    PMC->PMC_PCER = (1 << ID_UDPHS);
-    // Enable 480MHZ
-    //AT91C_BASE_CKGR->CKGR_UCKR |= (AT91C_CKGR_PLLCOUNT & (3 << 20)) | AT91C_CKGR_UPLLEN;
-    CKGR->CKGR_UCKR |= ((0xf << 20) & (3 << 20)) | AT91C_CKGR_UPLLEN;
-    // Wait until UTMI PLL is locked
-    while ((PMC->PMC_SR & PMC_LOCKU) == 0);
-
-    // Reset and enable IP UDPHS
-    UDPHS->UDPHS_CTRL &= ~UDPHS_CTRL_EN_UDPHS;
-    UDPHS->UDPHS_CTRL |= UDPHS_CTRL_EN_UDPHS;
-
-	//USBCON = ((1<<USBE)|(1<<OTGPADE));	// start USB clock
-    UDPHS->UDPHS_IEN = 0;
-    UDPHS->UDPHS_CLRINT = UDPHS_CLRINT_UPSTR_RES
-                                   | UDPHS_CLRINT_ENDOFRSM
-                                   | UDPHS_CLRINT_WAKE_UP
-                                   | UDPHS_CLRINT_ENDRESET
-                                   | UDPHS_CLRINT_INT_SOF
-                                   | UDPHS_CLRINT_MICRO_SOF
-                                   | UDPHS_CLRINT_DET_SUSPD;
-
-    // Enable interrupts for EOR (End of Reset), wake up and SOF (start of frame)
-    //UDIEN = (1<<EORSTE)|(1<<SOFE);
-    UDPHS->UDPHS_IEN = UDPHS_IEN_ENDOFRSM
-                                | UDPHS_IEN_WAKE_UP
-                                | UDPHS_IEN_DET_SUSPD;
-
-	// enable attach resistor
-	//UDCON = 0;
-    UDPHS->UDPHS_CTRL &= ~UDPHS_CTRL_DETACH;   // Pull Up on DP
-    UDPHS->UDPHS_CTRL |= UDPHS_CTRL_PULLD_DIS; // Disable Pull Down
-
-	TX_RX_LED_INIT;
-*/}
-
-void USB_::detach()
+void USB_::detach(void)
 {
     UDPHS->UDPHS_CTRL |= UDPHS_CTRL_DETACH; // detach
     UDPHS->UDPHS_CTRL &= ~UDPHS_CTRL_PULLD_DIS; // Enable Pull Down
diff --git a/hardware/arduino/sam/cores/sam/USBDesc.h b/hardware/arduino/sam/cores/sam/USBDesc.h
index 1c3b28a0c..2f08783d2 100644
--- a/hardware/arduino/sam/cores/sam/USBDesc.h
+++ b/hardware/arduino/sam/cores/sam/USBDesc.h
@@ -58,11 +58,11 @@
 #define HID_TX HID_ENDPOINT_INT
 #endif
 
-#define IMANUFACTURER	1
-#define IPRODUCT		2
-#define USB_PID_LEONARDO 0x0034
-#define USB_PID_MICRO 0x0035
-#define ARDUINO_MODEL_USB_PID 0x0036
-#define USB_VID 0x2341	// arduino LLC vid
-#define USB_PID	ARDUINO_MODEL_USB_PID	
+#define IMANUFACTURER    (1u)
+#define IPRODUCT	       (2u)
+#define USB_PID_LEONARDO (0x0034u)
+#define USB_PID_MICRO    (0x0035u)
+#define USB_PID_DUE      (0x0036u)
 
+#define USB_VID          (0x2341u) // Arduino LLC vendor id
+#define USB_PID	         USB_PID_DUE	
diff --git a/hardware/arduino/sam/cores/sam/USB_driver.h b/hardware/arduino/sam/cores/sam/USB_driver.h
index 26fd9f6f0..e69de29bb 100644
--- a/hardware/arduino/sam/cores/sam/USB_driver.h
+++ b/hardware/arduino/sam/cores/sam/USB_driver.h
@@ -1,79 +0,0 @@
-/*
-  Copyright (c) 2011 Arduino.  All right reserved.
-
-  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
-*/
-
-#ifndef _USB_DRIVER_
-#define _USB_DRIVER_
-
-#include <stdint.h>
-
-extern inline void USBD_WaitIN( void ) ;
-extern inline void USBD_ClearIN( void ) ;
-extern inline void USBD_WaitOUT( void ) ;
-extern inline uint8_t USBD_WaitForINOrOUT( void ) ;
-extern inline void USBD_ClearOUT(void) ;
-
-extern void USBD_ClearRxFlag( unsigned char bEndpoint ) ;
-extern void USBD_Recv( volatile uint8_t* data, uint8_t count ) ;
-
-extern inline uint8_t USBD_Recv8( void ) ;
-extern inline void USBD_Send8( uint8_t d ) ;
-extern inline void USBD_SetEP( uint8_t ep ) ;
-extern inline u16 USBD_FifoByteCount( void ) ;
-extern inline uint8_t USBD_ReceivedSetupInt( void ) ;
-extern inline void USBD_ClearSetupInt( void ) ;
-extern inline void USBD_Stall( void ) ;
-extern inline uint8_t USBD_ReadWriteAllowed( void ) ;
-extern inline uint8_t USBD_Stalled( void ) ;
-
-extern uint8_t USBD_FifoFree( void ) ;
-
-extern inline void USBD_ReleaseRX( void ) ;
-extern inline void USBD_ReleaseTX( void ) ;
-extern inline uint8_t USBD_FrameNumber( void ) ;
-
-extern uint8_t USBD_GetConfiguration( void ) ;
-
-
-//	Number of bytes, assumes a rx endpoint
-extern uint8_t USBD_Available( uint8_t ep ) ;
-
-//	Non Blocking receive
-//	Return number of bytes read
-extern int USBD_Recv(uint8_t ep, void* d, int len) ;
-
-//	Recv 1 byte if ready
-extern int USBD_Recv(uint8_t ep) ;
-
-//	Space in send EP
-extern uint8_t USBD_SendSpace(uint8_t ep) ;
-
-//	Blocking Send of data to an endpoint
-extern int USBD_Send(uint8_t ep, const void* d, int len) ;
-extern void USBD_InitEP(uint8_t index, uint8_t type, uint8_t size) ;
-extern void USBD_InitEndpoints() ;
-
-//	Handle CLASS_INTERFACE requests
-extern bool USBD_ClassInterfaceRequest(Setup& setup) ;
-
-extern void USBD_InitControl(int end) ;
-extern void UDPHS_Handler( void ) ;
-
-extern void USBD_Attach( void ) ;
-extern void USBD_Detach( void ) ;
-
-#endif /* _USB_DRIVER_*/
diff --git a/hardware/arduino/sam/cores/sam/validation/build_gcc/gcc.mk b/hardware/arduino/sam/cores/sam/validation/build_gcc/gcc.mk
index f26b9b882..36951b468 100644
--- a/hardware/arduino/sam/cores/sam/validation/build_gcc/gcc.mk
+++ b/hardware/arduino/sam/cores/sam/validation/build_gcc/gcc.mk
@@ -30,7 +30,13 @@ GDB = $(CROSS_COMPILE)gdb
 SIZE = $(CROSS_COMPILE)size
 NM = $(CROSS_COMPILE)nm
 OBJCOPY = $(CROSS_COMPILE)objcopy
+
+ifeq ($(OS),Windows_NT)
 RM=cs-rm -Rf
+else
+RM=rm -Rf
+endif
+
 SEP=\\
 
 # ---------------------------------------------------------------------------------------
@@ -48,7 +54,7 @@ CFLAGS += -Wpacked -Wredundant-decls -Wnested-externs -Winline -Wlong-long
 CFLAGS += -Wunreachable-code
 CFLAGS += -Wcast-align
 
-CFLAGS += --param max-inline-insns-single=500 -mcpu=cortex-m3 -mthumb -mlong-calls -ffunction-sections -nostdlib 
+CFLAGS += --param max-inline-insns-single=500 -mcpu=cortex-m3 -mthumb -mlong-calls -ffunction-sections -nostdlib -std=c99
 CFLAGS += $(OPTIMIZATION) $(INCLUDES) -D$(CHIP) -D$(VARIANT)
 
 # To reduce application size use only integer printf function.
@@ -67,7 +73,7 @@ CPPFLAGS += -Wformat -Wmissing-format-attribute -Wno-deprecated-declarations
 CPPFLAGS += -Wpacked -Wredundant-decls -Winline -Wlong-long
 
 #-fno-rtti -fno-exceptions
-CPPFLAGS += --param max-inline-insns-single=500 -mcpu=cortex-m3 -mthumb -mlong-calls -ffunction-sections 
+CPPFLAGS += --param max-inline-insns-single=500 -mcpu=cortex-m3 -mthumb -mlong-calls -ffunction-sections -std=c++98
 CPPFLAGS += $(OPTIMIZATION) $(INCLUDES) -D$(CHIP)
 
 # To reduce application size use only integer printf function.
diff --git a/hardware/arduino/sam/cores/sam/validation/build_gcc/test.mk b/hardware/arduino/sam/cores/sam/validation/build_gcc/test.mk
index e64349433..66c17fdb5 100644
--- a/hardware/arduino/sam/cores/sam/validation/build_gcc/test.mk
+++ b/hardware/arduino/sam/cores/sam/validation/build_gcc/test.mk
@@ -30,8 +30,12 @@ ifeq ("$(VARIANT)", "sam3s_ek")
 CHIP=__SAM3S4C__
 else ifeq ("$(VARIANT)", "sam3u_ek")
 CHIP=__SAM3U4E__
-else ifeq ("$(VARIANT)", "arduino_due")
+else ifeq ("$(VARIANT)", "sam3x_ek")
+CHIP=__SAM3X8H__
+else ifeq ("$(VARIANT)", "arduino_due_u")
 CHIP=__SAM3U4E__
+else ifeq ("$(VARIANT)", "arduino_due_x")
+CHIP=__SAM3X8E__
 endif
 
 TOOLCHAIN=gcc
diff --git a/hardware/arduino/sam/system/CMSIS/Device/ATMEL/sam3u/include/component/component_udphs.h b/hardware/arduino/sam/system/CMSIS/Device/ATMEL/sam3u/include/component/component_udphs.h
index 0bb9f5733..6c8e9c22a 100644
--- a/hardware/arduino/sam/system/CMSIS/Device/ATMEL/sam3u/include/component/component_udphs.h
+++ b/hardware/arduino/sam/system/CMSIS/Device/ATMEL/sam3u/include/component/component_udphs.h
@@ -68,13 +68,9 @@ typedef struct {
   WoReg     UDPHS_EPTRST;     /**< \brief (Udphs Offset: 0x1C) UDPHS Endpoints Reset Register */
   RoReg     Reserved2[48];
   RwReg     UDPHS_TST;        /**< \brief (Udphs Offset: 0xE0) UDPHS Test Register */
-  RoReg     Reserved3[3];
-  RoReg     UDPHS_IPNAME1;    /**< \brief (Udphs Offset: 0xF0) UDPHS Name1 Register */
-  RoReg     UDPHS_IPNAME2;    /**< \brief (Udphs Offset: 0xF4) UDPHS Name2 Register */
-  RoReg     UDPHS_IPFEATURES; /**< \brief (Udphs Offset: 0xF8) UDPHS Features Register */
-  RoReg     Reserved4[1];
+  RoReg     Reserved3[7];
   UdphsEpt  UDPHS_EPT[UDPHSEPT_NUMBER]; /**< \brief (Udphs Offset: 0x100) endpoint = 0 .. 6 */
-  RoReg     Reserved5[72];
+  RoReg     Reserved4[72];
   UdphsDma  UDPHS_DMA[UDPHSDMA_NUMBER]; /**< \brief (Udphs Offset: 0x300) channel = 0 .. 5 */
 } Udphs;
 #endif /* !(defined(__ASSEMBLY__) || defined(__IAR_SYSTEMS_ASM__)) */
@@ -162,39 +158,6 @@ typedef struct {
 #define UDPHS_TST_TST_K (0x1u << 3) /**< \brief (UDPHS_TST) Test K Mode */
 #define UDPHS_TST_TST_PKT (0x1u << 4) /**< \brief (UDPHS_TST) Test Packet Mode */
 #define UDPHS_TST_OPMODE2 (0x1u << 5) /**< \brief (UDPHS_TST) OpMode2 */
-/* -------- UDPHS_IPNAME1 : (UDPHS Offset: 0xF0) UDPHS Name1 Register -------- */
-#define UDPHS_IPNAME1_IP_NAME1_Pos 0
-#define UDPHS_IPNAME1_IP_NAME1_Msk (0xffffffffu << UDPHS_IPNAME1_IP_NAME1_Pos) /**< \brief (UDPHS_IPNAME1)  */
-/* -------- UDPHS_IPNAME2 : (UDPHS Offset: 0xF4) UDPHS Name2 Register -------- */
-#define UDPHS_IPNAME2_IP_NAME2_Pos 0
-#define UDPHS_IPNAME2_IP_NAME2_Msk (0xffffffffu << UDPHS_IPNAME2_IP_NAME2_Pos) /**< \brief (UDPHS_IPNAME2)  */
-/* -------- UDPHS_IPFEATURES : (UDPHS Offset: 0xF8) UDPHS Features Register -------- */
-#define UDPHS_IPFEATURES_EPT_NBR_MAX_Pos 0
-#define UDPHS_IPFEATURES_EPT_NBR_MAX_Msk (0xfu << UDPHS_IPFEATURES_EPT_NBR_MAX_Pos) /**< \brief (UDPHS_IPFEATURES) Max Number of Endpoints */
-#define UDPHS_IPFEATURES_DMA_CHANNEL_NBR_Pos 4
-#define UDPHS_IPFEATURES_DMA_CHANNEL_NBR_Msk (0x7u << UDPHS_IPFEATURES_DMA_CHANNEL_NBR_Pos) /**< \brief (UDPHS_IPFEATURES) Number of DMA Channels */
-#define UDPHS_IPFEATURES_DMA_B_SIZ (0x1u << 7) /**< \brief (UDPHS_IPFEATURES) DMA Buffer Size */
-#define UDPHS_IPFEATURES_DMA_FIFO_WORD_DEPTH_Pos 8
-#define UDPHS_IPFEATURES_DMA_FIFO_WORD_DEPTH_Msk (0xfu << UDPHS_IPFEATURES_DMA_FIFO_WORD_DEPTH_Pos) /**< \brief (UDPHS_IPFEATURES) DMA FIFO Depth in Words */
-#define UDPHS_IPFEATURES_FIFO_MAX_SIZE_Pos 12
-#define UDPHS_IPFEATURES_FIFO_MAX_SIZE_Msk (0x7u << UDPHS_IPFEATURES_FIFO_MAX_SIZE_Pos) /**< \brief (UDPHS_IPFEATURES) DPRAM Size */
-#define UDPHS_IPFEATURES_BW_DPRAM (0x1u << 15) /**< \brief (UDPHS_IPFEATURES) DPRAM Byte Write Capability */
-#define UDPHS_IPFEATURES_DATAB16_8 (0x1u << 16) /**< \brief (UDPHS_IPFEATURES) UTMI DataBus16_8 */
-#define UDPHS_IPFEATURES_ISO_EPT_1 (0x1u << 17) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_2 (0x1u << 18) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_3 (0x1u << 19) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_4 (0x1u << 20) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_5 (0x1u << 21) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_6 (0x1u << 22) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_7 (0x1u << 23) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_8 (0x1u << 24) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_9 (0x1u << 25) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_10 (0x1u << 26) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_11 (0x1u << 27) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_12 (0x1u << 28) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_13 (0x1u << 29) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_14 (0x1u << 30) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
-#define UDPHS_IPFEATURES_ISO_EPT_15 (0x1u << 31) /**< \brief (UDPHS_IPFEATURES) Endpointx High Bandwidth Isochronous Capability */
 /* -------- UDPHS_EPTCFG : (UDPHS Offset: N/A) UDPHS Endpoint Configuration Register -------- */
 #define UDPHS_EPTCFG_EPT_SIZE_Pos 0
 #define UDPHS_EPTCFG_EPT_SIZE_Msk (0x7u << UDPHS_EPTCFG_EPT_SIZE_Pos) /**< \brief (UDPHS_EPTCFG) Endpoint Size */
diff --git a/hardware/arduino/sam/system/libsam/include/USB_driver.h b/hardware/arduino/sam/system/libsam/include/USB_driver.h
new file mode 100644
index 000000000..6a6950db3
--- /dev/null
+++ b/hardware/arduino/sam/system/libsam/include/USB_driver.h
@@ -0,0 +1,70 @@
+/*
+  Copyright (c) 2011 Arduino.  All right reserved.
+
+  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
+*/
+
+#ifndef _USB_DRIVER_
+#define _USB_DRIVER_
+
+#include <stdint.h>
+
+extern void USBD_WaitIN(void) ;
+extern void USBD_WaitOUT(void) ;
+extern void USBD_ClearIN(void) ;
+extern void USBD_ClearOUT(void) ;
+extern uint8_t USBD_WaitForINOrOUT(void) ;
+
+extern void USBD_ClearRxFlag( unsigned char bEndpoint ) ;
+
+extern void USBD_Stall(void) ;
+extern uint8_t USBD_Stalled(void) ;
+
+extern uint8_t USBD_ReceivedSetupInt(void) ;
+extern void USBD_ClearSetupInt(void) ;
+
+extern uint8_t USBD_ReadWriteAllowed(void) ;
+
+extern void USBD_SetEP( uint8_t ep ) ;
+extern uint16_t USBD_FifoByteCount(void) ;
+extern uint8_t USBD_FifoFree(void) ;
+
+extern void USBD_ReleaseRX(void) ;
+extern void USBD_ReleaseTX(void) ;
+extern uint8_t USBD_FrameNumber(void) ;
+
+extern uint8_t USBD_GetConfiguration(void) ;
+
+extern void USBD_Recv( volatile uint8_t* data, uint8_t count ) ;
+extern uint8_t USBD_Recv8(void) ;
+extern void USBD_Send8( uint8_t d ) ;
+//	Blocking Send of data to an endpoint
+extern int USBD_Send(uint8_t ep, const void* d, int len) ;
+//	Space in send EP
+extern uint8_t USBD_SendSpace(uint8_t ep) ;
+
+//	Number of bytes, assumes a rx endpoint
+extern uint8_t USBD_Available(uint8_t ep) ;
+
+
+extern void USBD_InitEP(uint8_t index, uint8_t type, uint8_t size) ;
+extern void USBD_InitEndpoints(void) ;
+
+extern void USBD_InitControl(int end) ;
+
+extern void USBD_Attach(void) ;
+extern void USBD_Detach(void) ;
+
+#endif /* _USB_DRIVER_*/
diff --git a/hardware/arduino/sam/system/libsam/include/udphs.h b/hardware/arduino/sam/system/libsam/include/udphs.h
index 7d823cbf7..beb02bf69 100644
--- a/hardware/arduino/sam/system/libsam/include/udphs.h
+++ b/hardware/arduino/sam/system/libsam/include/udphs.h
@@ -19,8 +19,6 @@
 #ifndef UDPHS_H_INCLUDED
 #define UDPHS_H_INCLUDED
 
-#include "arduino.h"
-
 #define NUM_IT_MAX 3
 
 #define EP_SINGLE_64 0x32	// EP0
diff --git a/hardware/arduino/sam/system/libsam/source/udp.c b/hardware/arduino/sam/system/libsam/source/udp.c
index 711569362..590e8f6f7 100644
--- a/hardware/arduino/sam/system/libsam/source/udp.c
+++ b/hardware/arduino/sam/system/libsam/source/udp.c
@@ -16,7 +16,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "Arduino.h"
+#include "chip.h"
 
 #if SAM3S_SERIES || SAM4S_SERIES
 
diff --git a/hardware/arduino/sam/system/libsam/source/udphs.c b/hardware/arduino/sam/system/libsam/source/udphs.c
index 4b898d148..9968924ae 100644
--- a/hardware/arduino/sam/system/libsam/source/udphs.c
+++ b/hardware/arduino/sam/system/libsam/source/udphs.c
@@ -16,7 +16,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "Arduino.h"
+#include "chip.h"
 
 #if SAM3U_SERIES
 
@@ -24,8 +24,8 @@
 #include "udphs.h"
 
 /// Max size of the FMA FIFO
-#define EPT_VIRTUAL_SIZE     16384
-#define SHIFT_INTERUPT    8
+#define EPT_VIRTUAL_SIZE  (16384u)
+#define SHIFT_INTERUPT    (8u)
 
 int _cmark;
 int _cend;
@@ -34,146 +34,109 @@ int _cend;
 unsigned int NumEndpoint=0;
 
 
-inline void USBD_WaitIN( void )
+void USBD_WaitIN(void)
 {
 //	while (!(UEINTX & (1<<TXINI)));
-    while (!(UDPHS->UDPHS_EPT[0].UDPHS_EPTSTA & UDPHS_EPTSTA_TX_PK_RDY));
+  while (!(UDPHS->UDPHS_EPT[0].UDPHS_EPTSTA & UDPHS_EPTSTA_TX_PK_RDY));
 }
 
-inline void USBD_ClearIN( void )
-{
-//	UEINTX = ~(1<<TXINI);
-   UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_TX_COMPLT; 
-}
-
-inline void USBD_WaitOUT( void )
+void USBD_WaitOUT(void)
 {
 //	while (!(UEINTX & (1<<RXOUTI)))
 //		;
-    // Waiting for Status stage
-    while (UDPHS_EPTSTA_RX_BK_RDY != (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_BK_RDY));
+  // Waiting for Status stage
+  while (UDPHS_EPTSTA_RX_BK_RDY != (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_BK_RDY));
 }
 
-inline uint8_t USBD_WaitForINOrOUT( void )
+void USBD_ClearIN(void)
+{
+//	UEINTX = ~(1<<TXINI);
+  UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_TX_COMPLT; 
+}
+
+void USBD_ClearOUT(void)
+{
+//	UEINTX = ~(1<<RXOUTI);
+  UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_RX_BK_RDY;
+}
+
+uint8_t USBD_WaitForINOrOUT(void)
 {
 //	while (!(UEINTX & ((1<<TXINI)|(1<<RXOUTI))))
 //		;
 //	return (UEINTX & (1<<RXOUTI)) == 0;
-    while (!(UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & (UDPHS_EPTSTA_RX_BK_RDY | UDPHS_EPTSTA_TX_PK_RDY)));
-  	return (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_BK_RDY) == 0;
+  while (!(UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & (UDPHS_EPTSTA_RX_BK_RDY | UDPHS_EPTSTA_TX_PK_RDY)));
+  return (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_BK_RDY) == 0;
 }
 
-inline void USBD_ClearOUT(void)
+void USBD_ClearRxFlag(unsigned char bEndpoint)
 {
-//	UEINTX = ~(1<<RXOUTI);
-    UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_RX_BK_RDY;
+  UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_RX_BK_RDY;
 }
 
-/*
-void USBD_ClearRxFlag( unsigned char bEndpoint )
+void USBD_Stall(void)
 {
-    UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTCLRSTA_RX_BK_RDY;
+//	UECONX = (1<<STALLRQ) | (1<<EPEN);
+  UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSETSTA = UDPHS_EPTSETSTA_FRCESTALL;
 }
-*/
 
-void USBD_Recv(volatile uint8_t* data, uint8_t count)
+uint8_t USBD_Stalled(void)
 {
-    uint8_t     *pFifo;
-
-    pFifo = (uint8_t*)((u32 *)UDPHS_EPTFIFO + (EPT_VIRTUAL_SIZE * NumEndpoint));
-
-    while (count--)
-		*data++ = pFifo[0]; // UEDATX;
-
-	RXLED1;					// light the RX LED
-	RxLEDPulse = TX_RX_LED_PULSE_MS;
+//	return UEINTX & (1<<STALLEDI);
+  // Check if the data has been STALLed
+  return ( UDPHS_EPTSTA_FRCESTALL == (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_FRCESTALL));
 }
 
-
-inline uint8_t USBD_Recv8( void )
+uint8_t USBD_ReceivedSetupInt(void)
 {
-    uint8_t     *pFifo;
-
-	RXLED1;					// light the RX LED
-	RxLEDPulse = TX_RX_LED_PULSE_MS;
-
-    pFifo = (uint8_t*)((u32 *)UDPHS_EPTFIFO + (EPT_VIRTUAL_SIZE * NumEndpoint));
-
-//	return UEDATX;
-    return (pFifo[0]);
+//	return UEINTX & (1<<RXSTPI);
+  return ( UDPHS_EPTSTA_RX_SETUP == (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_SETUP) );
 }
 
-inline void USBD_Send8(uint8_t d)
+void USBD_ClearSetupInt(void)
 {
-    uint8_t     *pFifo;
-    pFifo = (uint8_t*)((u32 *)UDPHS_EPTFIFO + (EPT_VIRTUAL_SIZE * NumEndpoint));
-//	UEDATX = d;
-    pFifo[0] =d;
+//	UEINTX = ~((1<<RXSTPI) | (1<<RXOUTI) | (1<<TXINI));
+  UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTSTA_RX_SETUP | UDPHS_EPTCLRSTA_RX_BK_RDY | UDPHS_EPTCLRSTA_TX_COMPLT;
 }
 
-inline void USBD_SetEP(uint8_t ep)
+uint8_t USBD_ReadWriteAllowed(void)
+{
+	//return UEINTX & (1<<RWAL);
+  return 1;
+}
+
+void USBD_SetEP(uint8_t ep)
 {
 //	UENUM = ep;
 	NumEndpoint = ep & 7;
 }
 
-inline u16 USBD_FifoByteCount()
+uint16_t USBD_FifoByteCount(void)
 {
 //	return UEBCLX;
-    // SAM3X
-    //return ((UOTGHS->UOTGHS_DEVEPTISR[ep] & UOTGHS_DEVEPTISR_BYCT_Msk) >> UOTGHS_DEVEPTISR_BYCT_Pos);
-    // SAM3U //AT91C_UDPHS_BYTE_COUNT (0x7FF << 20)
-    return ((UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & (0x7FF << 20)) >> 20);
+  // SAM3X
+  //return ((UOTGHS->UOTGHS_DEVEPTISR[ep] & UOTGHS_DEVEPTISR_BYCT_Msk) >> UOTGHS_DEVEPTISR_BYCT_Pos);
+  // SAM3U //AT91C_UDPHS_BYTE_COUNT (0x7FF << 20)
+  return ((UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_BYTE_COUNT_Msk) >> UDPHS_EPTSTA_BYTE_COUNT_Pos);
 }
 
-inline uint8_t USBD_ReceivedSetupInt()
-{
-//	return UEINTX & (1<<RXSTPI);
-    return ( UDPHS_EPTSTA_RX_SETUP == (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_RX_SETUP) );
-}
-
-inline void USBD_ClearSetupInt()
-{
-//	UEINTX = ~((1<<RXSTPI) | (1<<RXOUTI) | (1<<TXINI));
-    UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTCLRSTA = UDPHS_EPTSTA_RX_SETUP | UDPHS_EPTCLRSTA_RX_BK_RDY | UDPHS_EPTCLRSTA_TX_COMPLT;
-}
-
-inline void USBD_Stall()
-{
-//	UECONX = (1<<STALLRQ) | (1<<EPEN);
-    UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSETSTA = UDPHS_EPTSETSTA_FRCESTALL;
-}
-
-inline uint8_t USBD_ReadWriteAllowed()
-{
-	//return UEINTX & (1<<RWAL);
-    return 1;
-}
-
-inline uint8_t USBD_Stalled()
-{
-//	return UEINTX & (1<<STALLEDI);
-    // Check if the data has been STALLed
-    return ( UDPHS_EPTSTA_FRCESTALL == (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_FRCESTALL));
-}
-
-uint8_t USBD_FifoFree()
+uint8_t USBD_FifoFree(void)
 {
 //	return UEINTX & (1<<FIFOCON);
-    return( 0 != (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_TX_PK_RDY ));
+  return( 0 != (UDPHS->UDPHS_EPT[NumEndpoint].UDPHS_EPTSTA & UDPHS_EPTSTA_TX_PK_RDY ));
 }
 
-//inline void USBD_ReleaseRX()
-//{
-//	UEINTX = 0x6B;	// FIFOCON=0 NAKINI=1 RWAL=1 NAKOUTI=0 RXSTPI=1 RXOUTI=0 STALLEDI=1 TXINI=1
-//}
+void USBD_ReleaseRX(void)
+{
+	UEINTX = 0x6B;	// FIFOCON=0 NAKINI=1 RWAL=1 NAKOUTI=0 RXSTPI=1 RXOUTI=0 STALLEDI=1 TXINI=1
+}
 
-//inline void USBD_ReleaseTX()
-//{
-//	UEINTX = 0x3A;	// FIFOCON=0 NAKINI=0 RWAL=1 NAKOUTI=1 RXSTPI=1 RXOUTI=0 STALLEDI=1 TXINI=0
-//}
+void USBD_ReleaseTX()
+{
+	UEINTX = 0x3A;	// FIFOCON=0 NAKINI=0 RWAL=1 NAKOUTI=1 RXSTPI=1 RXOUTI=0 STALLEDI=1 TXINI=0
+}
 
-inline uint8_t USBD_FrameNumber()
+uint8_t USBD_FrameNumber(void)
 {
 	return UDFNUML;
 }
@@ -183,49 +146,42 @@ uint8_t USBD_GetConfiguration(void)
 	return _usbConfiguration;
 }
 
-//	Number of bytes, assumes a rx endpoint
-uint8_t USBD_Available(uint8_t ep)
+
+
+void USBD_Recv(volatile uint8_t* data, uint8_t count)
 {
-	SetEP(ep);
-	return FifoByteCount();
+  uint8_t     *pFifo;
+
+  pFifo = (uint8_t*)((uint32_t *)UDPHS_RAM_ADDR + (EPT_VIRTUAL_SIZE * NumEndpoint));
+
+  while (count--)
+  {
+    *data++ = pFifo[0];
+  }
+
+//	RXLED1;					// light the RX LED
+//	RxLEDPulse = TX_RX_LED_PULSE_MS;
 }
 
-//	Non Blocking receive
-//	Return number of bytes read
-int USBD_Recv(uint8_t ep, void* d, int len)
+uint8_t USBD_Recv8(void)
 {
-	if (!_usbConfiguration || len < 0)
-		return -1;
+    uint8_t     *pFifo;
 
-	SetEP(ep);
-	uint8_t n = FifoByteCount();
-	len = min(n,len);
-	n = len;
-	uint8_t* dst = (uint8_t*)d;
-	while (n--)
-		*dst++ = Recv8();
-//	if (len && !FifoByteCount())	// release empty buffer
-//		ReleaseRX();
+//	RXLED1;					// light the RX LED
+//	RxLEDPulse = TX_RX_LED_PULSE_MS;
 
-	return len;
+    pFifo = (uint8_t*)((uint32_t *)UDPHS_RAM_ADDR + (EPT_VIRTUAL_SIZE * NumEndpoint));
+
+//	return UEDATX;
+    return (pFifo[0]);
 }
 
-//	Recv 1 byte if ready
-int USBD_Recv(uint8_t ep)
+void USBD_Send8(uint8_t d)
 {
-	uint8_t c;
-	if (USB_Recv(ep,&c,1) != 1)
-		return -1;
-	return c;
-}
-
-//	Space in send EP
-uint8_t USBD_SendSpace(uint8_t ep)
-{
-	SetEP(ep);
-	if (!ReadWriteAllowed())
-		return 0;
-	return 64 - FifoByteCount();
+    uint8_t     *pFifo;
+    pFifo = (uint8_t*)((uint32_t *)UDPHS_RAM_ADDR + (EPT_VIRTUAL_SIZE * NumEndpoint));
+//	UEDATX = d;
+    pFifo[0] =d;
 }
 
 //	Blocking Send of data to an endpoint
@@ -279,6 +235,26 @@ int USBD_Send(uint8_t ep, const void* d, int len)
 }
 
 
+//	Space in send EP
+uint8_t USBD_SendSpace(uint8_t ep)
+{
+	SetEP(ep);
+	if (!ReadWriteAllowed())
+  {
+		return 0;
+  }
+  
+	return 64 - FifoByteCount();
+}
+
+//	Number of bytes, assumes a rx endpoint
+uint8_t USBD_Available(uint8_t ep)
+{
+	SetEP(ep);
+  
+	return FifoByteCount();
+}
+
 void USBD_InitEP(uint8_t index, uint8_t type, uint8_t size)
 {
 	UENUM = index;
@@ -288,7 +264,7 @@ void USBD_InitEP(uint8_t index, uint8_t type, uint8_t size)
 }
 
 
-void USBD_InitEndpoints()
+void USBD_InitEndpoints(void)
 {
 	for (uint8_t i = 1; i < sizeof(_initEndpoints); i++)
 	{
@@ -310,33 +286,17 @@ void USBD_InitEndpoints()
 ///\//	UERST = 0;
 }
 
-//	Handle CLASS_INTERFACE requests
-bool USBD_ClassInterfaceRequest(Setup& setup)
-{
-	uint8_t i = setup.wIndex;
-
-#ifdef CDC_ENABLED
-	if (CDC_ACM_INTERFACE == i)
-		return CDC_Setup(setup);
-#endif
-
-#ifdef HID_ENABLED
-	if (HID_INTERFACE == i)
-		return HID_Setup(setup);
-#endif
-	return false;
-}
-
-
 void USBD_InitControl(int end)
 {
 	SetEP(0);
-    UDPHS->UDPHS_EPT[0].UDPHS_EPTCFG = _initEndpoints[0];
-    while( (signed int)UDPHS_EPTCFG_EPT_MAPD != (signed int)((UDPHS->UDPHS_EPT[0].UDPHS_EPTCFG) & (unsigned int)UDPHS_EPTCFG_EPT_MAPD) )
-    ;
-    UDPHS->UDPHS_EPT[0].UDPHS_EPTCTLENB = UDPHS_EPTCTLENB_RX_BK_RDY 
-                                         | UDPHS_EPTCTLENB_RX_SETUP
-                                         | UDPHS_EPTCTLENB_EPT_ENABL;
+  UDPHS->UDPHS_EPT[0].UDPHS_EPTCFG = _initEndpoints[0];
+  
+  while( (signed int)UDPHS_EPTCFG_EPT_MAPD != (signed int)((UDPHS->UDPHS_EPT[0].UDPHS_EPTCFG) & (unsigned int)UDPHS_EPTCFG_EPT_MAPD) )
+  ;
+  
+  UDPHS->UDPHS_EPT[0].UDPHS_EPTCTLENB = UDPHS_EPTCTLENB_RX_BK_RDY 
+                                       | UDPHS_EPTCTLENB_RX_SETUP
+                                       | UDPHS_EPTCTLENB_EPT_ENABL;
 
 	_cmark = 0;
 	_cend = end;
diff --git a/hardware/arduino/sam/system/libsam/source/uotghs.c b/hardware/arduino/sam/system/libsam/source/uotghs.c
index 303121678..f0594143b 100644
--- a/hardware/arduino/sam/system/libsam/source/uotghs.c
+++ b/hardware/arduino/sam/system/libsam/source/uotghs.c
@@ -16,7 +16,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "Arduino.h"
+#include "chip.h"
 
 #if SAM3XA_SERIES
 
diff --git a/hardware/arduino/sam/variants/arduino_due_u/variant.cpp b/hardware/arduino/sam/variants/arduino_due_u/variant.cpp
index c98a30f63..136e6119b 100644
--- a/hardware/arduino/sam/variants/arduino_due_u/variant.cpp
+++ b/hardware/arduino/sam/variants/arduino_due_u/variant.cpp
@@ -266,12 +266,12 @@ extern const PinDescription g_APinDescription[]=
  */
 RingBuffer rx_buffer1 ;
 
-UARTClass Serial( UART, UART_IRQn, ID_UART, &rx_buffer1 ) ;
+UARTClass Serial1( UART, UART_IRQn, ID_UART, &rx_buffer1 ) ;
 
 // IT handlers
 void UART_Handler(void)
 {
-  Serial.IrqHandler() ;
+  Serial1.IrqHandler() ;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/hardware/arduino/sam/variants/arduino_due_u/variant.h b/hardware/arduino/sam/variants/arduino_due_u/variant.h
index b13eb4a3b..15323b623 100644
--- a/hardware/arduino/sam/variants/arduino_due_u/variant.h
+++ b/hardware/arduino/sam/variants/arduino_due_u/variant.h
@@ -162,7 +162,7 @@ static const uint8_t A13 = 67;
 
 #ifdef __cplusplus
 
-extern UARTClass Serial ;
+extern UARTClass Serial1 ;
 
 extern USARTClass Serial2 ;
 extern USARTClass Serial3 ;
diff --git a/hardware/arduino/sam/variants/arduino_due_x/variant.cpp b/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
index 7922afaa7..496e5f933 100644
--- a/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
+++ b/hardware/arduino/sam/variants/arduino_due_x/variant.cpp
@@ -272,12 +272,12 @@ extern const PinDescription g_APinDescription[]=
  */
 RingBuffer rx_buffer1 ;
 
-UARTClass Serial( UART, UART_IRQn, ID_UART, &rx_buffer1 ) ;
+UARTClass Serial1( UART, UART_IRQn, ID_UART, &rx_buffer1 ) ;
 
 // IT handlers
 void UART_Handler(void)
 {
-  Serial.IrqHandler() ;
+  Serial1.IrqHandler() ;
 }
 
 // ----------------------------------------------------------------------------
diff --git a/hardware/arduino/sam/variants/arduino_due_x/variant.h b/hardware/arduino/sam/variants/arduino_due_x/variant.h
index 5a65f2ea8..3408849c7 100644
--- a/hardware/arduino/sam/variants/arduino_due_x/variant.h
+++ b/hardware/arduino/sam/variants/arduino_due_x/variant.h
@@ -162,7 +162,7 @@ static const uint8_t A15 = 69;
 
 #ifdef __cplusplus
 
-extern UARTClass Serial ;
+extern UARTClass Serial1 ;
 
 extern USARTClass Serial2 ;
 extern USARTClass Serial3 ;