X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/8e21541e77dd0909a99a1ed1106a6df87d34a247..e464f6225860a0965e266732328d9d0948607c31:/common/usb_cdc.c?ds=inline

diff --git a/common/usb_cdc.c b/common/usb_cdc.c
index e13ddbe2..91a63cf3 100644
--- a/common/usb_cdc.c
+++ b/common/usb_cdc.c
@@ -33,34 +33,41 @@
  */
 
 #include "usb_cdc.h"
+#include "at91sam7s512.h"
 #include "config_gpio.h"
 
-#define MIN(a, b) (((a) < (b)) ? (a) : (b))
-#define MAX(a, b) (((a) > (b)) ? (a) : (b))
-#define AT91C_EP_IN_SIZE  0x40
+
+#define AT91C_EP_CONTROL     0
 #define AT91C_EP_OUT         1
-#define AT91C_EP_OUT_SIZE 0x40
 #define AT91C_EP_IN          2
+#define AT91C_EP_NOTIFY      3
+#define AT91C_EP_OUT_SIZE 0x40
+#define AT91C_EP_IN_SIZE  0x40
+
+// Language must always be 0.
+#define STR_LANGUAGE_CODES 0x00
+#define STR_MANUFACTURER   0x01
+#define STR_PRODUCT        0x02
 
-const char devDescriptor[] = {
+static const char devDescriptor[] = {
 	/* Device descriptor */
 	0x12,      // bLength
 	0x01,      // bDescriptorType
-	0x10,0x01, // Complies with USB Spec. Release (0110h = release 1.10)
-	0x02,      // bDeviceClass:    CDC class code
-	0x00,      // bDeviceSubclass: CDC class sub code
-	0x00,      // bDeviceProtocol: CDC Device protocol
+	0x00,0x02, // Complies with USB Spec. Release (0200h = release 2.0)
+	0x02,      // bDeviceClass:    (Communication Device Class)
+	0x00,      // bDeviceSubclass: (unused at this time)
+	0x00,      // bDeviceProtocol: (unused at this time)
 	0x08,      // bMaxPacketSize0
-	0x2d,0x2d, // Vendor ID (--)
-	0x4d,0x50, // Product ID (PM), transmitted in reverse
+	0xc4,0x9a, // Vendor ID (0x9ac4 = J. Westhues)
+	0x8f,0x4b, // Product ID (0x4b8f = Proxmark-3 RFID Instrument)
 	0x01,0x00, // Device release number (0001)
-	0x01,      // iManufacturer    // 0x01
-	0x00,      // iProduct
-	0x00,      // SerialNumber
+	STR_MANUFACTURER,  // iManufacturer
+	STR_PRODUCT,       // iProduct
+	0x00,      // iSerialNumber
 	0x01       // bNumConfigs
 };
 
-const char cfgDescriptor[] = {
+static const char cfgDescriptor[] = {
 	/* ============== CONFIGURATION 1 =========== */
 	/* Configuration 1 descriptor */
 	0x09,   // CbLength
@@ -71,88 +78,95 @@ const char cfgDescriptor[] = {
 	0x01,   // CbConfigurationValue
 	0x00,   // CiConfiguration
 	0xC0,   // CbmAttributes 0xA0
-	0x00,   // CMaxPower
+	0xFA,   // CMaxPower
 
-	/* Communication Class Interface Descriptor Requirement */
+	/* Interface 0 Descriptor: Communication Class Interface */
 	0x09, // bLength
 	0x04, // bDescriptorType
 	0x00, // bInterfaceNumber
 	0x00, // bAlternateSetting
 	0x01, // bNumEndpoints
-	0x02, // bInterfaceClass
-	0x02, // bInterfaceSubclass
-	0x00, // bInterfaceProtocol
+	0x02, // bInterfaceClass:       Communication Interface Class
+	0x02, // bInterfaceSubclass:    Abstract Control Model
+	0x01, // bInterfaceProtocol:    Common AT Commands, V.25ter
 	0x00, // iInterface
 
 	/* Header Functional Descriptor */
 	0x05, // bFunction Length
-	0x24, // bDescriptor type: CS_INTERFACE
-	0x00, // bDescriptor subtype: Header Func Desc
+	0x24, // bDescriptor type:      CS_INTERFACE
+	0x00, // bDescriptor subtype:   Header Functional Descriptor
 	0x10, // bcdCDC:1.1
 	0x01,
 
 	/* ACM Functional Descriptor */
 	0x04, // bFunctionLength
-	0x24, // bDescriptor Type: CS_INTERFACE
-	0x02, // bDescriptor Subtype: ACM Func Desc
-	0x00, // bmCapabilities
+	0x24, // bDescriptor Type:      CS_INTERFACE
+	0x02, // bDescriptor Subtype:   Abstract Control Management Functional Descriptor
+	0x02, // bmCapabilities:        D1: Device supports the request combination of Set_Line_Coding, Set_Control_Line_State, Get_Line_Coding, and the notification Serial_State
 
 	/* Union Functional Descriptor */
 	0x05, // bFunctionLength
-	0x24, // bDescriptorType: CS_INTERFACE
-	0x06, // bDescriptor Subtype: Union Func Desc
-	0x00, // bMasterInterface: Communication Class Interface
-	0x01, // bSlaveInterface0: Data Class Interface
+	0x24, // bDescriptorType:       CS_INTERFACE
+	0x06, // bDescriptor Subtype:   Union Functional Descriptor
+	0x00, // bMasterInterface:      Communication Class Interface
+	0x01, // bSlaveInterface0:      Data Class Interface
 
 	/* Call Management Functional Descriptor */
 	0x05, // bFunctionLength
-	0x24, // bDescriptor Type: CS_INTERFACE
-	0x01, // bDescriptor Subtype: Call Management Func Desc
-	0x00, // bmCapabilities: D1 + D0
-	0x01, // bDataInterface: Data Class Interface 1
+	0x24, // bDescriptor Type:      CS_INTERFACE
+	0x01, // bDescriptor Subtype:   Call Management Functional Descriptor
+	0x00, // bmCapabilities:        Device sends/receives call management information only over the Communication Class interface. Device does not handle call management itself
+	0x01, // bDataInterface:        Data Class Interface 1
 
 	/* Endpoint 1 descriptor */
 	0x07,   // bLength
 	0x05,   // bDescriptorType
-	0x83,   // bEndpointAddress, Endpoint 03 - IN
-	0x03,   // bmAttributes      INT
-	0x08,   // wMaxPacketSize
+	0x83,   // bEndpointAddress:    Endpoint 03 - IN
+	0x03,   // bmAttributes:        INT
+	0x08,   // wMaxPacketSize:      8
 	0x00,
 	0xFF,   // bInterval
 
-	/* Data Class Interface Descriptor Requirement */
+	/* Interface 1 Descriptor: Data Class Interface */
 	0x09, // bLength
 	0x04, // bDescriptorType
 	0x01, // bInterfaceNumber
 	0x00, // bAlternateSetting
 	0x02, // bNumEndpoints
-	0x0A, // bInterfaceClass
-	0x00, // bInterfaceSubclass
-	0x00, // bInterfaceProtocol
+	0x0A, // bInterfaceClass:       Data Interface Class
+	0x00, // bInterfaceSubclass:    not used
+	0x00, // bInterfaceProtocol:    No class specific protocol required)
 	0x00, // iInterface
 
-	/* First alternate setting */
 	/* Endpoint 1 descriptor */
 	0x07,   // bLength
 	0x05,   // bDescriptorType
-	0x01,   // bEndpointAddress, Endpoint 01 - OUT
-	0x02,   // bmAttributes      BULK
-	AT91C_EP_OUT_SIZE,   // wMaxPacketSize
+	0x01,   // bEndpointAddress:    Endpoint 01 - OUT
+	0x02,   // bmAttributes:        BULK
+	AT91C_EP_OUT_SIZE, // wMaxPacketSize
 	0x00,
 	0x00,   // bInterval
 
 	/* Endpoint 2 descriptor */
 	0x07,   // bLength
 	0x05,   // bDescriptorType
-	0x82,   // bEndpointAddress, Endpoint 02 - IN
-	0x02,   // bmAttributes      BULK
+	0x82,   // bEndpointAddress:    Endpoint 02 - IN
+	0x02,   // bmAttributes:        BULK
 	AT91C_EP_IN_SIZE,   // wMaxPacketSize
 	0x00,
 	0x00    // bInterval
 };
 
-const char strDescriptor[] = {
-  26,				// Length
+static const char StrDescLanguageCodes[] = {
+  4,			// Length
+  0x03,			// Type is string
+  0x09, 0x04	// supported language Code 0 = 0x0409 (English)
+};
+
+// Note: ModemManager (Linux) ignores Proxmark3 devices by matching the
+// manufacturer string "proxmark.org". Don't change this.
+static const char StrDescManufacturer[] = {
+  26,			// Length
   0x03,			// Type is string
   'p', 0x00,
   'r', 0x00,
@@ -165,11 +179,55 @@ const char strDescriptor[] = {
   '.', 0x00,
   'o', 0x00,
   'r', 0x00,
-  'g', 0x00,
+  'g', 0x00
+};
+
+static const char StrDescProduct[] = {
+  8,			// Length
+  0x03,			// Type is string
+  'P', 0x00,
+  'M', 0x00,
+  '3', 0x00
 };
 
+const char* getStringDescriptor(uint8_t idx)
+{
+	switch (idx) {
+		case STR_LANGUAGE_CODES:
+			return StrDescLanguageCodes;
+		case STR_MANUFACTURER:
+			return StrDescManufacturer;
+		case STR_PRODUCT:
+			return StrDescProduct;
+		default:
+			return NULL;
+	}
+}
+
+// Bitmap for all status bits in CSR which must be written as 1 to cause no effect
+#define REG_NO_EFFECT_1_ALL      AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RX_DATA_BK1 \
+                                |AT91C_UDP_STALLSENT   | AT91C_UDP_RXSETUP \
+                                |AT91C_UDP_TXCOMP
+
+// Clear flags in the UDP_CSR register
+#define UDP_CLEAR_EP_FLAGS(endpoint, flags) { \
+	volatile unsigned int reg; \
+	reg = pUdp->UDP_CSR[(endpoint)]; \
+	reg |= REG_NO_EFFECT_1_ALL; \
+	reg &= ~(flags); \
+	pUdp->UDP_CSR[(endpoint)] = reg; \
+} 
+
+// Set flags in the UDP_CSR register
+#define UDP_SET_EP_FLAGS(endpoint, flags) { \
+	volatile unsigned int reg; \
+	reg = pUdp->UDP_CSR[(endpoint)]; \
+	reg |= REG_NO_EFFECT_1_ALL; \
+	reg |= (flags); \
+	pUdp->UDP_CSR[(endpoint)] = reg; \
+}
 
-/* USB standard request code */
+/* USB standard request codes */
 #define STD_GET_STATUS_ZERO           0x0080
 #define STD_GET_STATUS_INTERFACE      0x0081
 #define STD_GET_STATUS_ENDPOINT       0x0082
@@ -209,6 +267,7 @@ AT91S_CDC_LINE_CODING line = {
 	0,      // None Parity
 	8};     // 8 Data bits
 
+
 void AT91F_CDC_Enumerate();
 
 AT91PS_UDP pUdp = AT91C_BASE_UDP;
@@ -216,52 +275,55 @@ byte_t btConfiguration = 0;
 byte_t btConnection    = 0;
 byte_t btReceiveBank   = AT91C_UDP_RX_DATA_BK0;
 
+
 //*----------------------------------------------------------------------------
 //* \fn    usb_disable
 //* \brief This function deactivates the USB device
 //*----------------------------------------------------------------------------
 void usb_disable() {
-  // Disconnect the USB device
-  AT91C_BASE_PIOA->PIO_ODR = GPIO_USB_PU;
-  
-  // Clear all lingering interrupts
-  if(pUdp->UDP_ISR & AT91C_UDP_ENDBUSRES) {
-    pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
-  }
+	// Disconnect the USB device
+	AT91C_BASE_PIOA->PIO_ODR = GPIO_USB_PU;
+
+	// Clear all lingering interrupts
+	if(pUdp->UDP_ISR & AT91C_UDP_ENDBUSRES) {
+		pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
+	}
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    usb_enable
 //* \brief This function Activates the USB device
 //*----------------------------------------------------------------------------
 void usb_enable() {
-  // Set the PLL USB Divider
-  AT91C_BASE_CKGR->CKGR_PLLR |= AT91C_CKGR_USBDIV_1 ;
-  
-  // Specific Chip USB Initialisation
-  // Enables the 48MHz USB clock UDPCK and System Peripheral USB Clock
-  AT91C_BASE_PMC->PMC_SCER = AT91C_PMC_UDP;
-  AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_UDP);
-  
-  // Enable UDP PullUp (USB_DP_PUP) : enable & Clear of the corresponding PIO
-  // Set in PIO mode and Configure in Output
-  AT91C_BASE_PIOA->PIO_PER = GPIO_USB_PU; // Set in PIO mode
+	// Set the PLL USB Divider
+	AT91C_BASE_CKGR->CKGR_PLLR |= AT91C_CKGR_USBDIV_1 ;
+
+	// Specific Chip USB Initialisation
+	// Enables the 48MHz USB clock UDPCK and System Peripheral USB Clock
+	AT91C_BASE_PMC->PMC_SCER = AT91C_PMC_UDP;
+	AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_UDP);
+
+	// Enable UDP PullUp (USB_DP_PUP) : enable & Clear of the corresponding PIO
+	// Set in PIO mode and Configure in Output
+	AT91C_BASE_PIOA->PIO_PER = GPIO_USB_PU; // Set in PIO mode
 	AT91C_BASE_PIOA->PIO_OER = GPIO_USB_PU; // Configure as Output
-  
-  // Clear for set the Pullup resistor
+
+	// Clear for set the Pullup resistor
 	AT91C_BASE_PIOA->PIO_CODR = GPIO_USB_PU;
-  
-  // Disconnect and reconnect USB controller for 100ms
-  usb_disable();
-  
-  // Wait for a short while
-  for (volatile size_t i=0; i<0x100000; i++);
 
-  // Reconnect USB reconnect
-  AT91C_BASE_PIOA->PIO_SODR = GPIO_USB_PU;
-  AT91C_BASE_PIOA->PIO_OER = GPIO_USB_PU;
+	// Disconnect and reconnect USB controller for 100ms
+	usb_disable();
+
+	// Wait for a short while
+	for (volatile size_t i=0; i<0x100000; i++);
+
+	// Reconnect USB reconnect
+	AT91C_BASE_PIOA->PIO_SODR = GPIO_USB_PU;
+	AT91C_BASE_PIOA->PIO_OER = GPIO_USB_PU;
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    usb_check
 //* \brief Test if the device is configured and handle enumeration
@@ -277,9 +339,8 @@ bool usb_check() {
 		// Enable the function
 		pUdp->UDP_FADDR = AT91C_UDP_FEN;
 		// Configure endpoint 0
-		pUdp->UDP_CSR[0] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_CTRL);
-	}
-	else if (isr & AT91C_UDP_EPINT0) {
+		pUdp->UDP_CSR[AT91C_EP_CONTROL] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_CTRL);
+	} else if (isr & AT91C_UDP_EPINT0) {
 		pUdp->UDP_ICR = AT91C_UDP_EPINT0;
 		AT91F_CDC_Enumerate();
 	}
@@ -289,10 +350,11 @@ bool usb_check() {
 
 bool usb_poll()
 {
-  if (!usb_check()) return false;
-  return (pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank);
+	if (!usb_check()) return false;
+	return (pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank);
 }
 
+
 /**
 	In github PR #129, some users appears to get a false positive from
 	usb_poll, which returns true, but the usb_read operation
@@ -303,7 +365,6 @@ bool usb_poll()
 **/
 bool usb_poll_validate_length()
 {
-
 	if (!usb_check()) return false;
 	if (!(pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank)) return false;
 	return (pUdp->UDP_CSR[AT91C_EP_OUT] >> 16) >  0;
@@ -326,7 +387,7 @@ uint32_t usb_read(byte_t* data, size_t len) {
 			len -= packetSize;
 			while(packetSize--)
 				data[nbBytesRcv++] = pUdp->UDP_FDR[AT91C_EP_OUT];
-			pUdp->UDP_CSR[AT91C_EP_OUT] &= ~(bank);
+			UDP_CLEAR_EP_FLAGS(AT91C_EP_OUT, bank);
 			if (bank == AT91C_UDP_RX_DATA_BK0) {
 				bank = AT91C_UDP_RX_DATA_BK1;
 			} else {
@@ -340,48 +401,54 @@ uint32_t usb_read(byte_t* data, size_t len) {
 	return nbBytesRcv;
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    usb_write
 //* \brief Send through endpoint 2
 //*----------------------------------------------------------------------------
 uint32_t usb_write(const byte_t* data, const size_t len) {
-  size_t length = len;
+	size_t length = len;
 	uint32_t cpt = 0;
 
-  if (!length) return 0;
-  if (!usb_check()) return 0;
-  
+	if (!length) return 0;
+	if (!usb_check()) return 0;
+
 	// Send the first packet
-	cpt = MIN(length, AT91C_EP_IN_SIZE-1);
+	cpt = MIN(length, AT91C_EP_IN_SIZE);
 	length -= cpt;
-	while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
-	pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;
+	while (cpt--) {
+		pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
+	}
+	UDP_SET_EP_FLAGS(AT91C_EP_IN, AT91C_UDP_TXPKTRDY);
 
 	while (length) {
-		// Fill the second bank
-		cpt = MIN(length, AT91C_EP_IN_SIZE-1);
+		// Fill the next bank
+		cpt = MIN(length, AT91C_EP_IN_SIZE);
 		length -= cpt;
-		while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
-		// Wait for the the first bank to be sent
+		while (cpt--) {
+			pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
+		}
+		// Wait for the previous bank to be sent
 		while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
 			if (!usb_check()) return length;
-    }
-		pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
+		}
+		UDP_CLEAR_EP_FLAGS(AT91C_EP_IN, AT91C_UDP_TXCOMP);
 		while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);
-		pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;
+		UDP_SET_EP_FLAGS(AT91C_EP_IN, AT91C_UDP_TXPKTRDY);
 	}
-  
+
 	// Wait for the end of transfer
 	while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
 		if (!usb_check()) return length;
-  }
-  
-	pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
+	}
+
+	UDP_CLEAR_EP_FLAGS(AT91C_EP_IN, AT91C_UDP_TXCOMP);
 	while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);
 
 	return length;
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    AT91F_USB_SendData
 //* \brief Send Data through the control endpoint
@@ -400,52 +467,55 @@ static void AT91F_USB_SendData(AT91PS_UDP pUdp, const char *pData, uint32_t leng
 		while (cpt--)
 			pUdp->UDP_FDR[0] = *pData++;
 
-		if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
-			pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
-			while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
+		if (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP) {
+			UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_TXCOMP);
+			while (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP);
 		}
 
-		pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
+		UDP_SET_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_TXPKTRDY);
 		do {
-			csr = pUdp->UDP_CSR[0];
+			csr = pUdp->UDP_CSR[AT91C_EP_CONTROL];
 
 			// Data IN stage has been stopped by a status OUT
 			if (csr & AT91C_UDP_RX_DATA_BK0) {
-				pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
+				UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_RX_DATA_BK0);
 				return;
 			}
 		} while ( !(csr & AT91C_UDP_TXCOMP) );
 
 	} while (length);
 
-	if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
-		pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
-		while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
+	if (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP) {
+		UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_TXCOMP);
+		while (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP);
 	}
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    AT91F_USB_SendZlp
 //* \brief Send zero length packet through the control endpoint
 //*----------------------------------------------------------------------------
 void AT91F_USB_SendZlp(AT91PS_UDP pUdp) {
-	pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
-	while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) );
-	pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
-	while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
+	UDP_SET_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_TXPKTRDY);
+	while ( !(pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP) );
+	UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_TXCOMP);
+	while (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_TXCOMP);
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    AT91F_USB_SendStall
 //* \brief Stall the control endpoint
 //*----------------------------------------------------------------------------
 void AT91F_USB_SendStall(AT91PS_UDP pUdp) {
-	pUdp->UDP_CSR[0] |= AT91C_UDP_FORCESTALL;
-	while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_ISOERROR) );
-	pUdp->UDP_CSR[0] &= ~(AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR);
-	while (pUdp->UDP_CSR[0] & (AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR));
+	UDP_SET_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_FORCESTALL);
+	while ( !(pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_ISOERROR) );
+	UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR);
+	while (pUdp->UDP_CSR[AT91C_EP_CONTROL] & (AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR));
 }
 
+
 //*----------------------------------------------------------------------------
 //* \fn    AT91F_CDC_Enumerate
 //* \brief This function is a callback invoked when a SETUP packet is received
@@ -454,24 +524,24 @@ void AT91F_CDC_Enumerate() {
 	byte_t bmRequestType, bRequest;
 	uint16_t wValue, wIndex, wLength, wStatus;
 
-	if ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RXSETUP) )
+	if ( !(pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_RXSETUP) )
 		return;
 
-	bmRequestType = pUdp->UDP_FDR[0];
-	bRequest      = pUdp->UDP_FDR[0];
-	wValue        = (pUdp->UDP_FDR[0] & 0xFF);
-	wValue       |= (pUdp->UDP_FDR[0] << 8);
-	wIndex        = (pUdp->UDP_FDR[0] & 0xFF);
-	wIndex       |= (pUdp->UDP_FDR[0] << 8);
-	wLength       = (pUdp->UDP_FDR[0] & 0xFF);
-	wLength      |= (pUdp->UDP_FDR[0] << 8);
-
-	if (bmRequestType & 0x80) {
-		pUdp->UDP_CSR[0] |= AT91C_UDP_DIR;
-		while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_DIR) );
+	bmRequestType = pUdp->UDP_FDR[AT91C_EP_CONTROL];
+	bRequest      = pUdp->UDP_FDR[AT91C_EP_CONTROL];
+	wValue        = (pUdp->UDP_FDR[AT91C_EP_CONTROL] & 0xFF);
+	wValue       |= (pUdp->UDP_FDR[AT91C_EP_CONTROL] << 8);
+	wIndex        = (pUdp->UDP_FDR[AT91C_EP_CONTROL] & 0xFF);
+	wIndex       |= (pUdp->UDP_FDR[AT91C_EP_CONTROL] << 8);
+	wLength       = (pUdp->UDP_FDR[AT91C_EP_CONTROL] & 0xFF);
+	wLength      |= (pUdp->UDP_FDR[AT91C_EP_CONTROL] << 8);
+
+	if (bmRequestType & 0x80) {	// Data Phase Transfer Direction Device to Host
+		UDP_SET_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_DIR);
+		while ( !(pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_DIR) );
 	}
-	pUdp->UDP_CSR[0] &= ~AT91C_UDP_RXSETUP;
-	while ( (pUdp->UDP_CSR[0]  & AT91C_UDP_RXSETUP)  );
+	UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_RXSETUP);
+	while ( (pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_RXSETUP)  );
 
 	// Handle supported standard device request Cf Table 9-3 in USB specification Rev 1.1
 	switch ((bRequest << 8) | bmRequestType) {
@@ -480,8 +550,14 @@ void AT91F_CDC_Enumerate() {
 			AT91F_USB_SendData(pUdp, devDescriptor, MIN(sizeof(devDescriptor), wLength));
 		else if (wValue == 0x200)  // Return Configuration Descriptor
 			AT91F_USB_SendData(pUdp, cfgDescriptor, MIN(sizeof(cfgDescriptor), wLength));
-		else if ((wValue & 0x300) == 0x300)  // Return String Descriptor
-			AT91F_USB_SendData(pUdp, strDescriptor, MIN(sizeof(strDescriptor), wLength));
+		else if ((wValue & 0xF00) == 0x300) { // Return String Descriptor
+			const char *strDescriptor = getStringDescriptor(wValue & 0xff);
+			if (strDescriptor != NULL) {
+				AT91F_USB_SendData(pUdp, strDescriptor, MIN(strDescriptor[0], wLength));
+			} else {
+				AT91F_USB_SendStall(pUdp);
+			}
+		}
 		else
 			AT91F_USB_SendStall(pUdp);
 		break;
@@ -494,29 +570,29 @@ void AT91F_CDC_Enumerate() {
 		btConfiguration = wValue;
 		AT91F_USB_SendZlp(pUdp);
 		pUdp->UDP_GLBSTATE  = (wValue) ? AT91C_UDP_CONFG : AT91C_UDP_FADDEN;
-		pUdp->UDP_CSR[1] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT) : 0;
-		pUdp->UDP_CSR[2] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN)  : 0;
-		pUdp->UDP_CSR[3] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN)   : 0;
+		pUdp->UDP_CSR[AT91C_EP_OUT]    = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT) : 0;
+		pUdp->UDP_CSR[AT91C_EP_IN]     = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN)  : 0;
+		pUdp->UDP_CSR[AT91C_EP_NOTIFY] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN)   : 0;
 		break;
 	case STD_GET_CONFIGURATION:
 		AT91F_USB_SendData(pUdp, (char *) &(btConfiguration), sizeof(btConfiguration));
 		break;
 	case STD_GET_STATUS_ZERO:
-		wStatus = 0;
+		wStatus = 0;	// Device is Bus powered, remote wakeup disabled
 		AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 		break;
 	case STD_GET_STATUS_INTERFACE:
-		wStatus = 0;
+		wStatus = 0; 	// reserved for future use
 		AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 		break;
 	case STD_GET_STATUS_ENDPOINT:
 		wStatus = 0;
 		wIndex &= 0x0F;
-		if ((pUdp->UDP_GLBSTATE & AT91C_UDP_CONFG) && (wIndex <= 3)) {
+		if ((pUdp->UDP_GLBSTATE & AT91C_UDP_CONFG) && (wIndex <= AT91C_EP_NOTIFY)) {
 			wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
 			AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 		}
-		else if ((pUdp->UDP_GLBSTATE & AT91C_UDP_FADDEN) && (wIndex == 0)) {
+		else if ((pUdp->UDP_GLBSTATE & AT91C_UDP_FADDEN) && (wIndex == AT91C_EP_CONTROL)) {
 			wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
 			AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 		}
@@ -531,7 +607,7 @@ void AT91F_CDC_Enumerate() {
 		break;
 	case STD_SET_FEATURE_ENDPOINT:
 		wIndex &= 0x0F;
-		if ((wValue == 0) && wIndex && (wIndex <= 3)) {
+		if ((wValue == 0) && (wIndex >= AT91C_EP_OUT) && (wIndex <= AT91C_EP_NOTIFY)) {
 			pUdp->UDP_CSR[wIndex] = 0;
 			AT91F_USB_SendZlp(pUdp);
 		}
@@ -546,13 +622,13 @@ void AT91F_CDC_Enumerate() {
 		break;
 	case STD_CLEAR_FEATURE_ENDPOINT:
 		wIndex &= 0x0F;
-		if ((wValue == 0) && wIndex && (wIndex <= 3)) {
-			if (wIndex == 1)
-				pUdp->UDP_CSR[1] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT);
-			else if (wIndex == 2)
-				pUdp->UDP_CSR[2] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN);
-			else if (wIndex == 3)
-				pUdp->UDP_CSR[3] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_ISO_IN);
+		if ((wValue == 0) && (wIndex >= AT91C_EP_OUT) && (wIndex <= AT91C_EP_NOTIFY)) {
+			if (wIndex == AT91C_EP_OUT)
+				pUdp->UDP_CSR[AT91C_EP_OUT] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT);
+			else if (wIndex == AT91C_EP_IN)
+				pUdp->UDP_CSR[AT91C_EP_IN] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN);
+			else if (wIndex == AT91C_EP_NOTIFY)
+				pUdp->UDP_CSR[AT91C_EP_NOTIFY] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN);
 			AT91F_USB_SendZlp(pUdp);
 		}
 		else
@@ -561,8 +637,8 @@ void AT91F_CDC_Enumerate() {
 
 	// handle CDC class requests
 	case SET_LINE_CODING:
-		while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RX_DATA_BK0) );
-		pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
+		while ( !(pUdp->UDP_CSR[AT91C_EP_CONTROL] & AT91C_UDP_RX_DATA_BK0) );
+		UDP_CLEAR_EP_FLAGS(AT91C_EP_CONTROL, AT91C_UDP_RX_DATA_BK0);
 		AT91F_USB_SendZlp(pUdp);
 		break;
 	case GET_LINE_CODING: