[AVR] Discover newer bootloader at runtime

Replaces #4280, only checks for the bootloader once

Tested with Hoodloader2, should work with every LUFA-derived bootloader released after 2014 (.apitable_signatures section must be placed at end of the flash)

BootloaderAPITable.S :

.global BootloaderAPI_Signatures
BootloaderAPI_Signatures:

    .long BOOT_START_ADDR ; Start address of the bootloader
    .word 0xDF00 ; Signature for the CDC class bootloader
    .word 0xDCFB ; Signature for a LUFA class bootloader

makefile:

BOOT_API_LD_FLAGS    += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures,  BootloaderAPI_Signatures,  8)

Author: facchinm

hardware/arduino/avr/boards.txt

@@ -46,6 +46,57 @@ yun.build.extra_flags={build.usb_flags}
 
 ##############################################################
 
+yun101.name=Arduino/Genuino Yún 101
+yun101.upload.via_ssh=true
+
+yun101.vid.0=0x2341
+yun101.pid.0=0x0051
+yun101.vid.1=0x2341
+yun101.pid.1=0x8051
+
+yun101.upload.tool=avrdude
+yun101.upload.protocol=avr109
+yun101.upload.maximum_size=28672
+yun101.upload.maximum_data_size=2560
+yun101.upload.speed=57600
+yun101.upload.disable_flushing=true
+yun101.upload.use_1200bps_touch=true
+yun101.upload.wait_for_upload_port=true
+
+yun101.bootloader.tool=avrdude
+yun101.bootloader.low_fuses=0xff
+yun101.bootloader.high_fuses=0xd8
+yun101.bootloader.extended_fuses=0xfb
+yun101.bootloader.file=caterina2/Caterina2_ArduinoYun101.hex
+yun101.bootloader.unlock_bits=0x3F
+yun101.bootloader.lock_bits=0x2F
+
+yun101.vid.2=0x2341
+yun101.pid.2=0x8251
+yun101.vid.2.build.vid=0x2341
+yun101.vid.2.build.pid=0x8251
+yun101.vid.2.build.usb_product="Genuino Yun101"
+yun101.vid.2.bootloader.file=caterina2/Caterina2_GenuinoYun101.hex
+
+yun101.vid.3=0x2341
+yun101.pid.3=0x0251
+yun101.vid.3.build.vid=0x2341
+yun101.vid.3.build.pid=0x8251
+yun101.vid.3.build.usb_product="Genuino Yun101"
+yun101.vid.3.bootloader.file=caterina2/Caterina2_GenuinoYun101.hex
+
+yun101.build.mcu=atmega32u4
+yun101.build.f_cpu=16000000L
+yun101.build.vid=0x2341
+yun101.build.pid=0x8051
+yun101.build.usb_product="Arduino Yun101"
+yun101.build.board=AVR_YUN
+yun101.build.core=arduino
+yun101.build.variant=yun
+yun101.build.extra_flags={build.usb_flags}
+
+##############################################################
+
 uno.name=Arduino/Genuino Uno
 
 uno.vid.0=0x2341

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),
@@ -803,6 +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/platform.txt

@@ -109,6 +109,7 @@ tools.avrdude.bootloader.params.verbose=-v
 tools.avrdude.bootloader.params.quiet=-q -q
 tools.avrdude.bootloader.pattern="{cmd.path}" "-C{config.path}" {bootloader.verbose} -p{build.mcu} -c{protocol} {program.extra_params} "-Uflash:w:{runtime.platform.path}/bootloaders/{bootloader.file}:i" -Ulock:w:{bootloader.lock_bits}:m
 
+tools.avrdude_remote.upload.pattern=/usr/bin/run-avrdude /tmp/sketch.hex {upload.verbose} -p{build.mcu} -l{bootloader.low_fuses} -h{bootloader.high_fuses} -e{bootloader.extended_fuses}
 
 # USB Default Flags
 # Default blank usb manufacturer will be filled in at compile time

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 */