add a way to get quite unique iSerial descriptor

Author: facchinm

hardware/arduino/avr/cores/arduino/USBCore.cpp

@@ -18,6 +18,7 @@
 
 #include "USBAPI.h"
 #include "PluggableUSB.h"
+#include <stdlib.h>
 
 #if defined(USBCON)
 
@@ -69,10 +70,10 @@ const u8 STRING_MANUFACTURER[] PROGMEM = USB_MANUFACTURER;
 
 //	DEVICE DESCRIPTOR
 const DeviceDescriptor USB_DeviceDescriptor =
-	D_DEVICE(0x00,0x00,0x00,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,0,1);
+	D_DEVICE(0x00,0x00,0x00,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,ISERIAL,1);
 
 const DeviceDescriptor USB_DeviceDescriptorB =
-	D_DEVICE(0xEF,0x02,0x01,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,0,1);
+	D_DEVICE(0xEF,0x02,0x01,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,ISERIAL,1);
 
 //==================================================================
 //==================================================================
@@ -81,6 +82,8 @@ volatile u8 _usbConfiguration = 0;
 volatile u8 _usbCurrentStatus = 0; // meaning of bits see usb_20.pdf, Figure 9-4. Information Returned by a GetStatus() Request to a Device
 volatile u8 _usbSuspendState = 0; // copy of UDINT to check SUSPI and WAKEUPI bits
 
+static int iSerial = 0;
+
 static inline void WaitIN(void)
 {
 	while (!(UEINTX & (1<<TXINI)))
@@ -427,6 +430,19 @@ static bool USB_SendStringDescriptor(const u8*string_P, u8 string_len) {
         return true;
 }
 
+static bool USB_SendStringDescriptorRAM(u8* string_P, u8 string_len) {
+        SendControl(2 + string_len * 2);
+        SendControl(3);
+        for(u8 i = 0; i < string_len; i++) {
+                bool r = SendControl(string_P[i]);
+                r &= SendControl(0); // high byte
+                if(!r) {
+                        return false;
+                }
+        }
+        return true;
+}
+
 //	Does not timeout or cross fifo boundaries
 //	Will only work for transfers <= 64 bytes
 //	TODO
@@ -442,10 +458,10 @@ int SendInterfaces()
 {
 	u8 interfaces = 0;
 
-	CDC_GetInterface(&interfaces);
+	iSerial = CDC_GetInterface(&interfaces);
 
 #ifdef PLUGGABLE_USB_ENABLED
-	PUSB_GetInterface(&interfaces);
+	iSerial += PUSB_GetInterface(&interfaces);
 #endif
 
 	return interfaces;
@@ -505,6 +521,11 @@ bool SendDescriptor(USBSetup& setup)
 		else if (setup.wValueL == IMANUFACTURER) {
 			return USB_SendStringDescriptor(STRING_MANUFACTURER, strlen(USB_MANUFACTURER));
 		}
+		else if (setup.wValueL == ISERIAL) {
+			char StringNum[4];
+			itoa(iSerial, StringNum, 10);
+			return USB_SendStringDescriptorRAM((u8*)StringNum, strlen(StringNum));
+		}
 		else
 			return false;
 	}

hardware/arduino/avr/cores/arduino/USBDesc.h

@@ -36,4 +36,4 @@
 
 #define IMANUFACTURER	1
 #define IPRODUCT		2
-
+#define ISERIAL			3