renamed DiskLoader to Caterina (after Leonardo's mom)

1 files changed, 251 insertions, 0 deletions

diff --git a/bootloaders/caterina/src/Caterina.cpp b/bootloaders/caterina/src/Caterina.cpp
new file mode 100644
index 0000000..7ef6fa8
--- /dev/null
+++ b/bootloaders/caterina/src/Caterina.cpp
@@ -0,0 +1,251 @@
+
+
+#include "Platform.h"
+
+//	This bootloader creates a composite Serial device
+//
+//	The serial interface supports a STK500v1 protocol that is very similar to optiboot
+//
+//	The bootloader will timeout and start the firmware after a few hundred milliseconds
+//	if a usb connection is not detected.
+//	
+//	The tweakier code is to keep the bootloader below 2k (no interrupt table, for example)
+
+extern "C"
+void entrypoint(void) __attribute__ ((naked)) __attribute__ ((section (".vectors")));
+void entrypoint(void)
+{
+	asm volatile (
+		"eor	r1,		r1\n"	// Zero register
+		"out	0x3F,	r1\n"	// SREG
+		"ldi	r28,	0xFF\n"
+		"ldi	r29,	0x0A\n"
+		"out	0x3E,	r29\n"	// SPH
+		"out	0x3D,	r28\n"	// SPL
+		"rjmp	main"			// Stack is all set up, start the main code
+		::);
+}
+
+uint8_t _flashbuf[128];
+uint8_t _inSync;
+uint8_t _ok;
+extern volatile uint8_t _ejected;
+extern volatile uint16_t _timeout;
+
+void Program(uint8_t ep, uint16_t page, uint8_t count)
+{
+	uint8_t write = page < 30*1024;		// Don't write over firmware please
+	if (write)
+		boot_page_erase(page);
+
+	Recv(ep,_flashbuf,count);		// Read while page is erasing
+
+	if (!write)
+		return;
+
+	boot_spm_busy_wait();			// Wait until the memory is erased.
+
+	count >>= 1;
+	uint16_t* p = (uint16_t*)page;
+	uint16_t* b = (uint16_t*)_flashbuf;
+	for (uint8_t i = 0; i < count; i++)
+		boot_page_fill(p++, b[i]);
+
+    boot_page_write(page);
+    boot_spm_busy_wait();
+    boot_rww_enable ();
+}
+
+void StartSketch();
+int USBGetChar();
+#define getch USBGetChar
+
+#define HW_VER	 0x02
+#define SW_MAJOR 0x01
+#define SW_MINOR 0x10
+
+#define STK_OK              0x10
+#define STK_INSYNC          0x14  // ' '
+#define CRC_EOP             0x20  // 'SPACE'
+#define STK_GET_SYNC        0x30  // '0'
+
+#define STK_GET_PARAMETER   0x41  // 'A'
+#define STK_SET_DEVICE      0x42  // 'B'
+#define STK_SET_DEVICE_EXT  0x45  // 'E'
+#define STK_LOAD_ADDRESS    0x55  // 'U'
+#define STK_UNIVERSAL       0x56  // 'V'
+#define STK_PROG_PAGE       0x64  // 'd'
+#define STK_READ_PAGE       0x74  // 't'
+#define STK_READ_SIGN       0x75  // 'u'
+
+extern const uint8_t _readSize[] PROGMEM;
+const uint8_t _readSize[] = 
+{
+	STK_GET_PARAMETER,	1,
+	STK_SET_DEVICE,		20,
+	STK_SET_DEVICE_EXT,	5,
+	STK_UNIVERSAL,		4,
+	STK_LOAD_ADDRESS,	2,
+	STK_PROG_PAGE,		3,
+	STK_READ_PAGE,		3,
+	0,0
+};
+
+extern const uint8_t _consts[] PROGMEM;
+const uint8_t _consts[] = 
+{
+	SIGNATURE_0,
+	SIGNATURE_1,
+	SIGNATURE_2,
+	HW_VER,		// Hardware version
+	SW_MAJOR,	// Software major version
+	SW_MINOR,	// Software minor version
+	0x03,		// Unknown but seems to be required by avr studio 3.56
+	0x00,		// 
+};
+
+
+void USBInit(void);
+int main(void) __attribute__ ((naked));
+
+//	STK500v1 main loop, very similar to optiboot in protocol and implementation
+int main()
+{
+	uint8_t MCUSR_state = MCUSR;	// store the reason for the reset
+	MCUSR &= ~(1 << WDRF);			// must clear the watchdog reset flag before disabling and reenabling WDT
+	wdt_disable();
+	TX_LED_OFF();
+	RX_LED_OFF();
+	L_LED_OFF();
+	if (MCUSR_state & (1<<WDRF) && (pgm_read_word(0) != 0xFFFF)) {
+		StartSketch();				// if the reset was caused by WDT and if a sketch is already present then run the sketch instead of the bootloader
+	}	
+	BOARD_INIT();
+	USBInit();
+
+	_inSync = STK_INSYNC;
+	_ok = STK_OK;
+
+	if (pgm_read_word(0) != 0xFFFF)
+		_ejected = 1;
+
+	for(;;)
+	{
+		uint8_t* packet = _flashbuf;
+		uint16_t address = 0;
+		for (;;)
+		{
+			uint8_t cmd = getch();
+
+			//	Read packet contents
+			uint8_t len;
+			const uint8_t* rs = _readSize;
+			for(;;)
+			{
+				uint8_t c = pgm_read_byte(rs++);
+				len = pgm_read_byte(rs++);
+				if (c == cmd || c == 0)
+					break;
+			}
+			_timeout = 0;
+			//	Read params
+			Recv(CDC_RX,packet,len);
+
+			//	Send a response
+			uint8_t send = 0;
+			const uint8_t* pgm = _consts+7;			// 0
+			if (STK_GET_PARAMETER == cmd)
+			{
+				uint8_t i = packet[0] - 0x80;
+				if (i > 2)
+					i = (i == 0x18) ? 3 : 4;	// 0x80:HW_VER,0x81:SW_MAJOR,0x82:SW_MINOR,0x18:3 or 0
+				pgm = _consts + i + 3;
+				send = 1;
+			}
+
+			else if (STK_UNIVERSAL == cmd)
+			{
+				if (packet[0] == 0x30)
+					pgm = _consts + packet[2];	// read signature
+				send = 1;
+			}
+			
+			//	Read signature bytes
+			else if (STK_READ_SIGN == cmd)
+			{
+				pgm = _consts;
+				send = 3;
+			}
+
+			else if (STK_LOAD_ADDRESS == cmd)
+			{
+				address = *((uint16_t*)packet);		// word addresses
+				address += address;
+			}
+
+			else if (STK_PROG_PAGE == cmd)
+			{
+				Program(CDC_RX,address,packet[1]);
+			}
+
+			else if (STK_READ_PAGE == cmd)
+			{
+				send = packet[1];
+				pgm = (const uint8_t*)address;
+				address += send; // not sure of this is required
+			}
+
+			// Check sync
+			if (getch() != ' ')
+				break;
+			Transfer(CDC_TX,&_inSync,1);
+
+			// Send result
+			if (send)
+				Transfer(CDC_TX|TRANSFER_PGM,pgm,send);	// All from pgm memory
+
+			//	Send ok
+			Transfer(CDC_TX|TRANSFER_RELEASE,&_ok,1);
+
+			if (cmd == 'Q')
+				break;
+		}
+		_timeout = 500;		// wait a moment before exiting the bootloader - may need to finish responding to 'Q' for example
+		_ejected = 1;
+	}
+}
+
+//	Nice breathing LED indicates we are in the firmware
+uint16_t _pulse;
+void LEDPulse()
+{
+	_pulse += 4;
+	uint8_t p = _pulse >> 9;
+	if (p > 63)
+		p = 127-p;
+	p += p;
+	if (((uint8_t)_pulse) > p)
+		L_LED_OFF();
+	else
+		L_LED_ON();
+}
+
+void StartSketch()
+{
+	TX_LED_OFF();	// switch off the RX and TX LEDs before starting the user sketch
+	RX_LED_OFF();
+	UDCON = 1;		// Detach USB
+	UDIEN = 0;
+	asm volatile (	// Reset vector to run firmware
+		"clr r30\n"
+		"clr r31\n"
+		"ijmp\n"
+	::);
+}
+
+void Reset() 
+{
+	wdt_enable(WDTO_15MS);	// reset the microcontroller to reinitialize all IO and other registers
+	for (;;) 
+		;
+}