Opta: provide USB VID/PID in bootloader

When the various combination have been decided we need to change boards.txt (with particular attention to dfu-utils commandline)

Author: facchinm

variants/OPTA/pins_arduino.h

@@ -139,8 +139,29 @@ static const uint8_t SCK  = PIN_SPI_SCK;
 
 #define SERIAL_CDC			1
 #define HAS_UNIQUE_ISERIAL_DESCRIPTOR
-#define BOARD_VENDORID		0x2341
-#define BOARD_PRODUCTID		0x0264
+
+// Use these only if bootloader data is not available / valid
+#define _BOARD_VENDORID		0x2341
+#define _BOARD_PRODUCTID	0x0264
+
+static uint8_t* bootloader_data = (uint8_t*)(0x801F000);
+static inline bool _isBootloaderDataValid() {
+    return bootloader_data[0] == 0xA0;
+}
+static inline uint16_t _getVid_() {
+    if (_isBootloaderDataValid()) {
+        return bootloader_data[1] | ((uint16_t)bootloader_data[2] << 8);
+    } else {
+        return _BOARD_VENDORID;
+    }
+}
+static inline uint16_t _getPid_() {
+    if (_isBootloaderDataValid()) {
+        return bootloader_data[3] | ((uint16_t)bootloader_data[4] << 8);
+    } else {
+        return _BOARD_PRODUCTID;
+    }
+}
 #define BOARD_NAME			"Arduino Opta"
 
 #define DFU_MAGIC_SERIAL_ONLY_RESET   0xb0