reduce sizae and compat work

- current firmware need more space -> reduce bootloader size from 4K => 2K
- remove timer ISR
- remove interrupt vectors from linked binary
- make avr910 bootloader entry command more robust (old: 'S', new: { 0x1B, 'S'} )
- add compat bootloader entry command (rx: { 0x1B, 0xAA } -> tx: 'MKBL')
- do not leave bootloader after upgrading twiboot slave
- do not erase local flash when upgrading twiboot slave
- remove readable chipinfo output from twiboot slaves

.gitignore

@@ -4,3 +4,4 @@
 *.hex
 *.lst
 *.map
+ldscript-no-vectors.x

Makefile

@@ -6,23 +6,33 @@ OPTIMIZE       = -Os
 DEFS           =
 LIBS           =
 
+LDSCRIPT_SRC  := /usr/lib/ldscripts/avr5.x
+LDSCRIPT_DST  := ldscript-no-vectors.x
+
 # Override is only needed by avr-lib build system.
 override CFLAGS        = -g -Wall $(OPTIMIZE) -mmcu=$(MCU_TARGET) $(DEFS)
-override LDFLAGS       = -Wl,-Map,$(PRG).map,--section-start=.text=0xF000
+override LDFLAGS       = -Wl,-Map,$(PRG).map,--section-start=.text=0xF800,-T$(LDSCRIPT_DST)
 
 CC             = avr-gcc
 OBJCOPY        = avr-objcopy
 OBJDUMP        = avr-objdump
 SIZE           = avr-size
 
+#LDSCRIPT_SRC  := $(shell LANG=C $(CC) $(CFLAGS) -Wl,--verbose 2> /dev/null | awk '/^opened script file (.*)$$/{ print $$4 }')
+
 all: $(PRG).elf lst text
 	$(SIZE) -x -A $(PRG).elf
 
-$(PRG).elf: $(OBJ)
+$(PRG).elf: $(OBJ) | $(LDSCRIPT_DST)
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ $(LIBS)
 
+$(LDSCRIPT_DST): $(LDSCRIPT_SRC)
+# remove all lines with *vectors* and insert DISCARD line above .text declaration
+	sed -e '/.*vectors.*/d' -e 's/\(^[ \t]*\)\(.text[ \t]*\:\)$$/\1\/DISCARD\/ : { *(.vectors) }\n\1\2/g' $^ > $@
+#	-diff -uNr $^ $@ > $@.diff
+
 clean:
-	rm -rf *.o $(PRG).lst $(PRG).map $(PRG).elf $(PRG).hex $(PRG).bin
+	rm -rf *.o $(PRG).lst $(PRG).map $(PRG).elf $(PRG).hex $(PRG).bin $(LDSCRIPT_DST)
 
 lst:  $(PRG).lst
 
@@ -41,4 +51,4 @@ bin:  $(PRG).bin
 	$(OBJCOPY) -j .text -j .data -O binary $< $@
 
 install: text
-	avrdude -c dragon_isp -P usb -p m644p -B0.3 -V -U flash:w:$(PRG).hex
+	avrdude -c dragon_isp -P usb -p m644p -V -U flash:w:$(PRG).hex

README

@@ -0,0 +1,25 @@
+1) Flash FC firmware:
+# reset running firmware (MCU will execute bootloader only for ~1s!)
+$ echo -e -n "#aR@S\r" > /dev/ttyUSB1
+
+# flash new firmware
+$ avrdude -p m644p -c butterfly -b 57600 -P /dev/ttyUSB1 -U flash:w:/tmp/Flight-Ctrl_MEGA644_V0_82a.hex
+
+
+2) Flash BLMC firmware (via twiboot):
+# enter bootloader (0x1B, 'S'), select first twi-slave ('1'):
+$ echo -e -n "\x1BS1" > /dev/ttyUSB1
+
+# flash new firmware
+$ avrdude -p m8 -c butterfly -b 57600 -P /dev/ttyUSB1 -U flash:w:/tmp/blmc.hex
+
+# select next twi-slave (bootloader is still active)
+$ echo -e -n "2" > /dev/ttyUSB1
+
+
+3) Other Commands:
+'0'       => select FC internal flash/eeprom
+'1' - '4' => select twi-slave 1-4, print bootloader version
+'I'       => start application on selected twi-slave, print application version
+'l'       => start selected motor
+'k'       => stop selected motor

main.c

@@ -25,7 +25,7 @@
 /*
  * ATMega 644P:
  * Fuse E: 0xFD (2.7V BOD)
- * Fuse H: 0xDA (2048 words bootloader)
+ * Fuse H: 0xDC (1024 words bootloader)
  * Fuse L: 0xFF (ext. Crystal)
  */
 
@@ -35,15 +35,15 @@
 #define BAUDRATE 57600
 #define UART_CALC_BAUDRATE(baudRate) ((uint32_t)(F_CPU) / ((uint32_t)(baudRate)*16) -1)
 
-#define APP_END			0xF000
+#define APP_END			0xF7FF
 
 #define LED_RT			(1<<PORTB0)			/* low active */
 #define LED_GN			(1<<PORTB1)			/* high active */
 
 #define TWI_CLK			100000
-#define TWI_ADDRESS_BASE	0x20				/* 0x21 - 0x24 */
+#define TWI_ADDRESS_BASE	0x28				/* 0x29 - 0x2C */
 
-#define TWI_DEVCODE		0x77				/* Mega8 */
+#define TWI_DEVCODE		0x76				/* Mega8 */
 #define OWN_DEVCODE		0x74				/* Mega644 */
 #define OWN_SIGNATURE		{ 0x1E, 0x96, 0x0A }		/* Mega644P */
 
@@ -79,26 +79,14 @@ static uint8_t recvchar(void)
 	return UDR0;
 }
 
-static void print_byte(uint8_t val)
-{
-	uint8_t tmp = (val >> 4) & 0x0F;
-	sendchar((tmp < 0x0A) ? ('0' + tmp) : ('a' - 0x0A + tmp));
-
-	tmp = val & 0x0F;
-	sendchar((tmp < 0x0A) ? ('0' + tmp) : ('a' - 0x0A + tmp));
-}
-
-static uint8_t i2c_master_tx(uint8_t val)
+static void i2c_master_tx(uint8_t val)
 {
 	TWDR = val;
 	TWCR = (1<<TWINT) | (1<<TWEN);
 	loop_until_bit_is_set(TWCR, TWINT);
-
-	uint8_t status = TWSR & 0xF8;
-	return status;
 }
 
-static uint8_t i2c_master_rx(uint8_t *val, uint8_t ack)
+static uint8_t i2c_master_rx(uint8_t ack)
 {
 	if (ack)
 		TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
@@ -106,10 +94,7 @@ static uint8_t i2c_master_rx(uint8_t *val, uint8_t ack)
 		TWCR = (1<<TWINT) | (1<<TWEN);
 
 	loop_until_bit_is_set(TWCR, TWINT);
-	*val = TWDR;
-
-	uint8_t status = TWSR & 0xF8;
-	return status;
+	return TWDR;
 }
 
 static void i2c_stop(void)
@@ -125,7 +110,8 @@ static void i2c_start_address(uint8_t addr)
 		TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
 		loop_until_bit_is_set(TWCR, TWINT);
 
-		uint8_t status = i2c_master_tx(addr);
+		i2c_master_tx(addr);
+		uint8_t status = (TWSR & 0xF8);
 		if (status == 0x18 || status == 0x40)
 			break;
 
@@ -134,66 +120,64 @@ static void i2c_start_address(uint8_t addr)
 	}
 }
 
-/* wait 100x 10ms */
-volatile static uint8_t boot_timeout = 100;
-
-ISR(TIMER0_OVF_vect)
+static void i2c_switch_app(uint8_t i2c_dev, uint8_t app)
 {
-	static uint8_t cnt;
+	i2c_start_address(i2c_dev);
+	i2c_master_tx(CMD_SWITCH_APPLICATION);
+	i2c_master_tx(app);
+	i2c_stop();
 
-	/* come back in 10ms (@20MHz) */
-	TCNT0 = 0xFF - 195;
+	_delay_ms(20);
+}
+
+static void i2c_print_version(uint8_t i2c_dev)
+{
+	i2c_start_address(i2c_dev);
+	i2c_master_tx(CMD_READ_VERSION);
+	i2c_start_address(i2c_dev | 0x01);
 
-	/* blink LED while running */
-	cnt++;
-	cnt &= 0x03;
-	if (cnt == 0x00)
-		PORTB ^= LED_GN;
+	uint8_t cnt = 16;
+	while (cnt--) {
+		sendchar(i2c_master_rx(cnt));
+	}
 
-	if (boot_timeout > 0)
-		boot_timeout--;
+	i2c_stop();
 }
 
-static uint16_t address;
-static uint16_t page_size;
 static uint8_t page_buf[SPM_PAGESIZE];
 
-
 static void eraseFlash(void)
 {
-	uint32_t addr = 0;
-	while (APP_END > addr) {
-		boot_page_erase(addr);
+	uint16_t address = 0;
+	while (APP_END < address) {
+		boot_page_erase(address);
 		boot_spm_busy_wait();
-		addr += SPM_PAGESIZE;
+		address += SPM_PAGESIZE;
 	}
 	boot_rww_enable();
 }
 
-static uint16_t writeFlashPage(uint16_t waddr, uint16_t size)
+static void writeFlashPage(uint16_t address, uint16_t size)
 {
-	uint32_t pagestart = (uint32_t)waddr<<1;
-	uint32_t baddr = pagestart;
+	uint16_t pagestart = address;
 	uint16_t data;
 	uint8_t *tmp = page_buf;
 
 	do {
 		data = *tmp++;
 		data |= *tmp++ << 8;
-		boot_page_fill(baddr, data);
+		boot_page_fill(address, data);
 
-		baddr += 2;
+		address += 2;
 		size -= 2;
 	} while (size);
 
 	boot_page_write(pagestart);
 	boot_spm_busy_wait();
 	boot_rww_enable();
-
-	return baddr>>1;
 }
 
-static uint16_t writeEEpromPage(uint16_t address, uint16_t size)
+static void writeEEpromPage(uint16_t address, uint16_t size)
 {
 	uint8_t *tmp = page_buf;
 
@@ -209,31 +193,22 @@ static uint16_t writeEEpromPage(uint16_t address, uint16_t size)
 
 		size--;
 	} while (size);
-
-	return address;
 }
 
-static uint16_t readFlashPage(uint16_t waddr, uint16_t size)
+static void readFlashPage(uint16_t address, uint16_t size)
 {
-	uint32_t baddr = (uint32_t)waddr<<1;
 	uint16_t data;
 
 	do {
-#if defined(RAMPZ)
-		data = pgm_read_word_far(baddr);
-#else
-		data = pgm_read_word_near(baddr);
-#endif
+		data = pgm_read_word_near(address);
 		sendchar(data);
 		sendchar((data >> 8));
-		baddr += 2;
+		address += 2;
 		size -= 2;
 	} while (size);
-
-	return baddr>>1;
 }
 
-static uint16_t readEEpromPage(uint16_t address, uint16_t size)
+static void readEEpromPage(uint16_t address, uint16_t size)
 {
 	do {
 		EEARL = address;
@@ -245,43 +220,36 @@ static uint16_t readEEpromPage(uint16_t address, uint16_t size)
 
 		size--;
 	} while (size);
-
-	return address;
 }
 
 /* 0-2: signature, 3: pagesize, 4-5: flash size, 6-7: eeprom size */
 static uint8_t chipinfo[8];
 
-void cmd_loop(void)
+void cmd_loop(uint8_t val)
 {
+	uint16_t address = 0;
+	uint16_t page_size = 0;
 	uint8_t i2c_dev = 0;
 
-	sendchar('F');
-	sendchar('C');
-	sendchar('_');
-	sendchar('B');
-	sendchar('O');
-	sendchar('O');
-	sendchar('T');
-
 	while (1) {
-		uint8_t val = recvchar();
+		uint8_t response = 0xFF;
+
 		// Autoincrement?
 		if (val == 'a') {
-			sendchar('Y');
+			response = 'Y';
 
 		// write address
         	} else if (val == 'A') {
 			address = recvchar();
 			address = (address << 8) | recvchar();
-			sendchar('\r');
+			response = '\r';
 
 		// Buffer load support
 		} else if (val == 'b') {
 			sendchar('Y');
 			page_size = (i2c_dev == 0) ? sizeof(page_buf) : chipinfo[3];
 			sendchar((page_size >> 8) & 0xFF);
-			sendchar(page_size & 0xFF);
+			response = page_size & 0Xff;
 
 		// Start buffer load
 		} else if (val == 'B') {
@@ -313,12 +281,13 @@ void cmd_loop(void)
 
 			} else {
 				if (val == 'F') {
-					address = writeFlashPage(address, size);
+					writeFlashPage(address, size);
 				} else if (val == 'E') {
-					address = writeEEpromPage(address, size);
+					writeEEpromPage(address, size);
 				}
+				address += size;
 			}
-			sendchar('\r');
+			response = '\r';
 
 		// Block read
 		} else if (val == 'g') {
@@ -335,8 +304,7 @@ void cmd_loop(void)
 
 				i2c_start_address(i2c_dev | 0x01);
 				while (size--) {
-					i2c_master_rx(&val, size > 0);
-					sendchar(val);
+					sendchar(i2c_master_rx(size > 0));
 					address++;
 				}
 
@@ -344,64 +312,48 @@ void cmd_loop(void)
 
 			} else {
 				if (val == 'F') {
-					address = readFlashPage(address, size);
+					readFlashPage(address, size);
 				} else if (val == 'E') {
-					address = readEEpromPage(address, size);
+					readEEpromPage(address, size);
 				}
+				address += size;
 			}
 
 		// Chip erase
 		} else if (val == 'e') {
-			eraseFlash();
-			sendchar('\r');
+			if (i2c_dev == 0) {
+				eraseFlash();
+			}
+			response = '\r';
 
 		// Exit upgrade
 		} else if (val == 'E') {
-			boot_timeout = 0;
 			sendchar('\r');
-			_delay_ms(10);
-			break;
-
-		// Enter programming mode
-		} else if (val == 'P') {
-			if (i2c_dev != 0) {
-				i2c_start_address(i2c_dev);
-				i2c_master_tx(CMD_SWITCH_APPLICATION);
-				i2c_master_tx(BOOTTYPE_BOOTLOADER);
-				i2c_stop();
-
-				_delay_ms(10);
+			if (i2c_dev == 0) {
+				return;
 			}
-			sendchar('\r');
 
-		// Leave programming mode
-		} else if (val == 'L') {
+		// Enter / Leave programming mode
+		} else if (val == 'P' || val == 'L') {
 			if (i2c_dev != 0) {
-				i2c_start_address(i2c_dev);
-				i2c_master_tx(CMD_SWITCH_APPLICATION);
-				i2c_master_tx(BOOTTYPE_APPLICATION);
-				i2c_stop();
+				val = (val == 'P') ? BOOTTYPE_BOOTLOADER : BOOTTYPE_APPLICATION;
+				i2c_switch_app(i2c_dev, val);
 			}
-			sendchar('\r');
+			response = '\r';
 
 		// return programmer type
 		} else if (val == 'p') {
-			sendchar('S');
+			response = 'S';
 
 		// Return device type
 		} else if (val == 't') {
 			sendchar((i2c_dev == 0) ? OWN_DEVCODE : TWI_DEVCODE);
-			sendchar(0);
+			response = '\0';
 
 		// clear and set LED ignored
-        	} else if ((val == 'x') || (val == 'y')) {
+		} else if ((val == 'x') || (val == 'y') || (val == 'T')) {
 			recvchar();
-			sendchar('\r');
-
-		// set device
-		} else if (val == 'T') {
-			recvchar();
-			sendchar('\r');
+			response = '\r';
 
 		// Return software identifier
 		} else if (val == 'S') {
@@ -411,58 +363,37 @@ void cmd_loop(void)
 			sendchar('B');
 			sendchar('O');
 			sendchar('O');
-			sendchar('T');
+			response = 'T';
 
 		// Return Software Version
 		} else if (val == 'V' || val == 'v') {
 			sendchar('0');
-			sendchar('8');
+			response = '8';
 
 		// Return Signature Bytes
 		} else if (val == 's') {
 			if (i2c_dev != 0) {
 				sendchar(chipinfo[2]);
 				sendchar(chipinfo[1]);
-				sendchar(chipinfo[0]);
+				response = chipinfo[0];
 
 			} else {
 				uint8_t sig[3] = OWN_SIGNATURE;
 				sendchar(sig[2]);
 				sendchar(sig[1]);
-				sendchar(sig[0]);
+				response = sig[0];
 			}
 
 		// set i2c target
 		} else if (val == '0') {
 			i2c_dev = 0;
-			sendchar(val);
 
 		} else if (val >= '1' && val <= '4') {
 			i2c_dev = (val - '0' + TWI_ADDRESS_BASE) << 1;
-			sendchar(val);
-			sendchar('<');
 
-			i2c_start_address(i2c_dev);
-			i2c_master_tx(CMD_SWITCH_APPLICATION);
-			i2c_master_tx(BOOTTYPE_BOOTLOADER);
-			i2c_stop();
-
-			for (val = 0; val < 10; val++)
-				_delay_ms(10);
-
-			i2c_start_address(i2c_dev);
-			i2c_master_tx(CMD_READ_VERSION);
-			i2c_start_address(i2c_dev | 0x01);
-
-			uint8_t cnt;
-			for (cnt = 0; cnt < 16; cnt++) {
-				i2c_master_rx(&val, (cnt != 15));
-				sendchar(val);
-			}
-
-			i2c_stop();
-
-			sendchar(',');
+			i2c_switch_app(i2c_dev, BOOTTYPE_BOOTLOADER);
+			_delay_ms(100);
+			i2c_print_version(i2c_dev);
 
 			i2c_start_address(i2c_dev);
 			i2c_master_tx(CMD_READ_MEMORY);
@@ -474,12 +405,7 @@ void cmd_loop(void)
 			uint8_t i;
 			for (i = 0; i < sizeof(chipinfo); i++) {
 				uint8_t more = (i < (sizeof(chipinfo) -1));
-				i2c_master_rx(&chipinfo[i], more);
-
-				sendchar('0');
-				sendchar('x');
-				print_byte(chipinfo[i]);
-				sendchar(more ? ',' : '>');
+				chipinfo[i] = i2c_master_rx(more);
 			}
 			i2c_stop();
 
@@ -489,39 +415,34 @@ void cmd_loop(void)
 				i2c_start_address(i2c_dev);
 				i2c_master_tx(0x00 + (val - 'k') * 0x10);
 				i2c_stop();
-
-				sendchar(val);
+				response = val;
 			}
 
-		// start Application / get Version
+		// get Version
 		} else if (val == 'I') {
 			if (i2c_dev != 0) {
-				i2c_start_address(i2c_dev);
-				i2c_master_tx(CMD_SWITCH_APPLICATION);
-				i2c_master_tx(BOOTTYPE_APPLICATION);
-				i2c_stop();
-
-				for (val = 0; val < 10; val++)
-					_delay_ms(10);
-
-				i2c_start_address(i2c_dev);
-				i2c_master_tx(CMD_READ_VERSION);
-				i2c_start_address(i2c_dev | 0x01);
-
-				sendchar('<');
-				uint8_t cnt;
-				for (cnt = 0; cnt < 16; cnt++) {
-					i2c_master_rx(&val, (cnt != 15));
-					sendchar(val);
-				}
-				sendchar('>');
-				i2c_stop();
+				i2c_switch_app(i2c_dev, BOOTTYPE_APPLICATION);
+				_delay_ms(100);
+				i2c_print_version(i2c_dev);
 			}
 
+		// fake MK-TOOL specific stuff
+		} else if (val == 0xAA) {
+			sendchar('M');
+			sendchar('K');
+			sendchar('B');
+			response = 'L';
+
 		/* ESC */
 		} else if (val != 0x1b) {
-			sendchar('?');
+			response = '?';
+		}
+
+		if (response != 0xFF) {
+			sendchar(response);
 		}
+
+		val = recvchar();
 	}
 }
 
@@ -532,7 +453,6 @@ static void (*jump_to_app)(void) __attribute__ ((noreturn)) = 0x0000;
  * system reset. So disable it as soon as possible.
  * automagically called on startup
  */
-#if defined (__AVR_ATmega88__) || defined (__AVR_ATmega168__)
 void disable_wdt_timer(void) __attribute__((naked, section(".init3")));
 void disable_wdt_timer(void)
 {
@@ -540,17 +460,15 @@ void disable_wdt_timer(void)
 	WDTCSR = (1<<WDCE) | (1<<WDE);
 	WDTCSR = (0<<WDE);
 }
-#endif
+
+/* linking without vectors, still need __vector_default */
+void __vector_default(void) {}
 
 int main(void) __attribute__ ((noreturn));
 int main(void)
 {
 	DDRB = LED_GN | LED_RT;
-	PORTB = LED_GN | LED_RT;
-
-	/* move interrupt-vectors to bootloader */
-	MCUCR = (1<<IVCE);
-	MCUCR = (1<<IVSEL);
+	PORTB = LED_RT;
 
 	/* Set baudrate */
 	UBRR0H = (UART_CALC_BAUDRATE(BAUDRATE)>>8) & 0xFF;
@@ -560,35 +478,32 @@ int main(void)
 	UCSR0B = (1<<TXEN0) | (1<<RXEN0);
 	UCSR0C = (1<<UCSZ01) | (1<<UCSZ00);
 
-	/* timer0: running with F_CPU/1024 */
-	TCCR0B = (1<<CS02) | (1<<CS00);
-
-	/* enable timer0 OVF interrupt */
-	TIMSK0 |= (1<<TOIE0);
-
 	/* enable TWI interface */
 	TWBR = ((F_CPU/TWI_CLK)-16)/2;
 	TWCR = (1<<TWSTO) | (1<<TWEN);
 
-	sei();
+	uint8_t prev = 0x00;
+	uint8_t boot_timeout = 100;
 
-	while (boot_timeout > 0) {
-		if (UCSR0A & (1<<RXC0))
-			if (recvchar() == 'S')
-				cmd_loop();
-	}
+	while (boot_timeout-- > 0) {
+		if (UCSR0A & (1<<RXC0)) {
+			uint8_t val = recvchar();
 
-	cli();
+			if (prev == 0x1B && (val == 0xAA || val == 'S')) {
+				PORTB |= LED_GN;
+				cmd_loop(val);
+				boot_timeout = 0;
+			}
 
-	/* move interrupt-vectors to applicaion */
-	MCUCR = (1<<IVCE);
-	MCUCR = (0<<IVSEL);
+			prev = val;
+		}
+		_delay_ms(10);
 
-	PORTB = LED_RT;
+		if (!(boot_timeout & 0x03))
+			PORTB ^= LED_GN;
+	}
 
-	uint8_t i;
-	for (i = 0; i < 10; i++)
-		_delay_ms(10);
+	PORTB = LED_RT;
 
 	jump_to_app();
 }