[DO NOT MERGE] Fix bootloader and USB improvements on 32u4

hardware/arduino/avr/cores/arduino/CDC.cpp

@@ -34,6 +34,8 @@ typedef struct
 static volatile LineInfo _usbLineInfo = { 57600, 0x00, 0x00, 0x00, 0x00 };
 static volatile int32_t breakValue = -1;
 
+bool _updatedLUFAbootloader = false;
+
 #define WEAK __attribute__ ((weak))
 
 extern const CDCDescriptor _cdcInterface PROGMEM;
@@ -99,24 +101,32 @@ bool CDC_Setup(USBSetup& setup)
 			// with a relatively long period so it can finish housekeeping tasks
 			// like servicing endpoints before the sketch ends
 
-#ifndef MAGIC_KEY
-#define MAGIC_KEY 0x7777
-#endif
-#ifndef MAGIC_KEY_POS
-#define MAGIC_KEY_POS 0x0800
+			uint16_t magic_key_pos = MAGIC_KEY_POS;
+
+// If we don't use the new RAMEND directly, check manually if we have a newer bootloader.
+// This is used to keep compatible with the old leonardo bootloaders.
+// You are still able to set the magic key position manually to RAMEND-1 to save a few bytes for this check.
+#if MAGIC_KEY_POS != (RAMEND-1)
+			// For future boards save the key in the inproblematic RAMEND
+			// Which is reserved for the main() return value (which will never return)
+			if (_updatedLUFAbootloader) {
+				// horray, we got a new bootloader!
+				magic_key_pos = (RAMEND-1);
+			}
 #endif
 
 			// We check DTR state to determine if host port is open (bit 0 of lineState).
 			if (1200 == _usbLineInfo.dwDTERate && (_usbLineInfo.lineState & 0x01) == 0)
 			{
 #if MAGIC_KEY_POS != (RAMEND-1)
-				*(uint16_t *)(RAMEND-1) = *(uint16_t *)MAGIC_KEY_POS;
-				*(uint16_t *)MAGIC_KEY_POS = MAGIC_KEY;
-#else
-				// for future boards save the key in the inproblematic RAMEND
-				// which is reserved for the main() return value (which will never return)
-				*(uint16_t *)MAGIC_KEY_POS = MAGIC_KEY;
+				// Backup ram value if its not a newer bootloader.
+				// This should avoid memory corruption at least a bit, not fully
+				if (magic_key_pos != (RAMEND-1)) {
+					*(uint16_t *)(RAMEND-1) = *(uint16_t *)magic_key_pos;
+				}
 #endif
+				// Store boot key
+				*(uint16_t *)magic_key_pos = MAGIC_KEY;
 				wdt_enable(WDTO_120MS);
 			}
 			else
@@ -129,10 +139,15 @@ bool CDC_Setup(USBSetup& setup)
 				wdt_disable();
 				wdt_reset();
 #if MAGIC_KEY_POS != (RAMEND-1)
-				*(uint16_t *)MAGIC_KEY_POS = *(uint16_t *)(RAMEND-1);
-#else
-				*(uint16_t *)MAGIC_KEY_POS = 0x0000;
+				// Restore backed up (old bootloader) magic key data
+				if (magic_key_pos != (RAMEND-1)) {
+					*(uint16_t *)magic_key_pos = *(uint16_t *)(RAMEND-1);
+				} else
 #endif
+				{
+				// Clean up RAMEND key
+					*(uint16_t *)magic_key_pos = 0x0000;
+				}
 			}
 		}
 		return true;

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

@@ -35,6 +35,7 @@ extern const u8 STRING_PRODUCT[] PROGMEM;
 extern const u8 STRING_MANUFACTURER[] PROGMEM;
 extern const DeviceDescriptor USB_DeviceDescriptor PROGMEM;
 extern const DeviceDescriptor USB_DeviceDescriptorB PROGMEM;
+extern bool _updatedLUFAbootloader;
 
 const u16 STRING_LANGUAGE[2] = {
 	(3<<8) | (2+2),
@@ -115,16 +116,10 @@ static inline void Recv(volatile u8* data, u8 count)
 {
 	while (count--)
 		*data++ = UEDATX;
-
-	RXLED1;					// light the RX LED
-	RxLEDPulse = TX_RX_LED_PULSE_MS;	
 }
 
 static inline u8 Recv8()
 {
-	RXLED1;					// light the RX LED
-	RxLEDPulse = TX_RX_LED_PULSE_MS;
-
 	return UEDATX;	
 }
 
@@ -226,6 +221,9 @@ int USB_Recv(u8 ep, void* d, int len)
 	if (!_usbConfiguration || len < 0)
 		return -1;
 
+	RXLED1;					// light the RX LED
+	RxLEDPulse = TX_RX_LED_PULSE_MS;
+
 	LockEP lock(ep);
 	u8 n = FifoByteCount();
 	len = min(n,len);
@@ -806,6 +804,12 @@ void USBDevice_::attach()
 	UDIEN = (1<<EORSTE) | (1<<SOFE) | (1<<SUSPE);	// Enable interrupts for EOR (End of Reset), SOF (start of frame) and SUSPEND
 
 	TX_RX_LED_INIT;
+
+#if MAGIC_KEY_POS != (RAMEND-1)
+	if (pgm_read_word(FLASHEND - 1) == NEW_LUFA_SIGNATURE) {
+		_updatedLUFAbootloader = true;
+	}
+#endif
 }
 
 void USBDevice_::detach()

hardware/arduino/avr/cores/arduino/USBCore.h

@@ -260,7 +260,7 @@ typedef struct
 
 
 #define D_DEVICE(_class,_subClass,_proto,_packetSize0,_vid,_pid,_version,_im,_ip,_is,_configs) \
-	{ 18, 1, 0x200, _class,_subClass,_proto,_packetSize0,_vid,_pid,_version,_im,_ip,_is,_configs }
+	{ 18, 1, 0x210, _class,_subClass,_proto,_packetSize0,_vid,_pid,_version,_im,_ip,_is,_configs }
 
 #define D_CONFIG(_totalLength,_interfaces) \
 	{ 9, 2, _totalLength,_interfaces, 1, 0, USB_CONFIG_BUS_POWERED | USB_CONFIG_REMOTE_WAKEUP, USB_CONFIG_POWER_MA(500) }

hardware/arduino/avr/variants/leonardo/pins_arduino.h

@@ -366,4 +366,22 @@ const uint8_t PROGMEM analog_pin_to_channel_PGM[] = {
 // Alias SerialUSB to Serial
 #define SerialUSB SERIAL_PORT_USBVIRTUAL
 
+// Bootloader related fields
+// Old Caterian bootloader places the MAGIC key into unsafe RAM locations (it can be rewritten
+// by the running sketch before to actual reboot).
+// Newer bootloaders, recognizable by the LUFA "signature" at the end of the flash, can handle both
+// the usafe and the safe location. Check once (in USBCore.cpp) if the bootloader in new, then set the global
+// _updatedLUFAbootloader variable to true/false and place the magic key consequently
+#ifndef MAGIC_KEY
+#define MAGIC_KEY 0x7777
+#endif
+
+#ifndef MAGIC_KEY_POS
+#define MAGIC_KEY_POS 0x0800
+#endif
+
+#ifndef NEW_LUFA_SIGNATURE
+#define NEW_LUFA_SIGNATURE 0xDCFB
+#endif
+
 #endif /* Pins_Arduino_h */