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prompt for bootloader trigger keys
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Prompt the user to press the bootloader trigger keys, both in
the serial monitor and by lighting up the right LEDs (assuming
there's already firmware that understands that.)

Signed-off-by: Taylor Yu <[email protected]>
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@tlyu @obra
tlyu authored and obra committed May 31, 2022
1 parent f840e91 commit 4f88e80
Showing 1 changed file with 138 additions and 60 deletions.
198 changes: 138 additions & 60 deletions etc/flash_firmware.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,27 @@ extern "C" {
#define ENDTRANS_DATA_NACK 3
#define ENDTRANS_ERROR 4

#define write_cmd(addr, data, sendStop) \
twi_writeTo((addr), (data), ELEMENTS(data), true, (sendStop))

// Reset delay, in milliseconds. Also retry interval for initial
// commands to bootloader.
//
// The ATtinys in the Model 01 ship with fuses programmed for a
// 64 ms reset delay (actually 8192 watchdog timer cycles, so
// maybe 65ms to 70ms in practice, given temperature and voltage
// variations). Also, the original Model 01 bootloader times out
// in that same period. So delay once and retry with an interval
// a little less than that, to make sure we hit the bootloader
// before it times out.
//
// (We could delay slightly longer for the initial delay, but
// we would miss the bootloader timeout if someone changed
// the fuses to a shorter startup delay.)
#define RESET_DELAY 60

#define debug_print(...) Serial.print(__VA_ARGS__)
#define debug_println(...) Serial.println(__VA_ARGS__)

void debug_print_result(uint8_t result) {
switch(result) {
Expand All @@ -36,9 +56,31 @@ void debug_print_result(uint8_t result) {
}
}

void debug_println_result(uint8_t result) {
debug_print_result(result);
debug_println();
}

#define LEFT_LEDS 0x58
#define RIGHT_LEDS (LEFT_LEDS | 0x03)

void turn_leds_off(uint8_t addr) {
uint8_t leds_off[] = { 0x03, 0x00, 0x00, 0x00 };
(void)write_cmd(addr, leds_off, true);
}

void setup() {
delay(2000);
// Turn on LED (and right hand) power, in case bootloader didn't
// do that for us (e.g., not coming straight off an ATmega flash.)
// That lets us explicitly turn them off, in case they're lit up
// from power cycling or bootloader status updates.
DDRC |= _BV(7);
PORTC |= _BV(7);
delay(3 * RESET_DELAY);
twi_init();

turn_leds_off(LEFT_LEDS);
turn_leds_off(RIGHT_LEDS);
}

// The LEFT ATTiny has a reset pin directly connected to the ATMega
Expand All @@ -48,6 +90,7 @@ void reset_left_attiny() {
PORTC &= ~_BV(6);
delay(30);
DDRC &= ~_BV(6); // Turn the ATTiny back on
delay(RESET_DELAY);
}

// The RIGHT ATTiny is on the other side of the wired i2c bus.
Expand All @@ -59,21 +102,53 @@ void reset_right_attiny() {
PORTC &= ~_BV(7);
delay(1000);
PORTC |= _BV(7); // Turn the ATTiny back on
delay(RESET_DELAY);
// In case power cycling caused any to turn on
turn_leds_off(LEFT_LEDS);
}

#define PROMPT_COLOR 0x00, 0x7f, 0x7f
void prompt_trigger(uint8_t addr) {
uint8_t left_prompt0[] = { 0x04, 0, PROMPT_COLOR };
uint8_t left_prompt1[] = { 0x04, 30, PROMPT_COLOR };
uint8_t right_prompt0[] = { 0x04, 1, PROMPT_COLOR };
uint8_t right_prompt1[] = { 0x04, 31, PROMPT_COLOR };
debug_println(F("Exceeded retry count"));
debug_print(F("Try holding down the bootloader keys on the "));
if (addr == LEFT_ADDRESS) {
debug_println(F("left side"));
(void)write_cmd(LEFT_LEDS, left_prompt0, true);
delay(1);
(void)write_cmd(LEFT_LEDS, left_prompt1, true);
delay(1000);
reset_left_attiny();
} else {
debug_println(F("right side"));
(void)write_cmd(RIGHT_LEDS, right_prompt0, true);
delay(1);
(void)write_cmd(RIGHT_LEDS, right_prompt1, true);
delay(1000);
reset_right_attiny();
}
}



void leds_success(uint8_t addr) {
uint8_t data[] = { 0x03, 0x00, 0x3f, 0x00 };
(void)write_cmd(addr, data, true);
}

uint8_t read_crc16(byte addr, byte *version, uint16_t *crc16, uint16_t offset, uint16_t length) {
uint8_t result = ENDTRANS_ADDR_NACK;


// get version and CRC16 // addr (lo) // addr (hi) // len (lo) // len (hi)
uint8_t data[] = { (0x06), (uint8_t)(offset & 0xff), (uint8_t)(offset >> 8), (uint8_t)(length & 0xff), (uint8_t)(length >> 8) };
result = twi_writeTo(addr, data, ELEMENTS(data), true, true);

// get version and CRC16
uint8_t data[] = {
(0x06),
(uint8_t)(offset & 0xff), (uint8_t)(offset >> 8), // addr
(uint8_t)(length & 0xff), (uint8_t)(length >> 8) // len
};

result = write_cmd(addr, data, true);
if (result != ENDTRANS_SUCCESS) {
return result;
}
Expand All @@ -97,43 +172,45 @@ uint8_t read_crc16(byte addr, byte *version, uint16_t *crc16, uint16_t offset, u


void get_version (byte addr) {

uint8_t retries = 0;
byte result = ENDTRANS_ADDR_NACK;

while (result != ENDTRANS_SUCCESS) {
debug_print(F("Reading CRC16: "));

byte version;
uint16_t crc16;
result = read_crc16(addr, &version, &crc16, 0, firmware_length);
debug_print_result(result);
debug_print(F("\r\n"));
debug_println_result(result);

if (result != ENDTRANS_SUCCESS) {
_delay_ms(100);
delay(RESET_DELAY);
if (++retries < 4) {
continue;
}
retries = 0;
prompt_trigger(addr);
continue;
}
debug_print(F("Version: "));
debug_print(version);
debug_print(F("\r\nExisting CRC16 of 0000-1FFF: "));
debug_print(crc16, HEX);
debug_print(F("\r\n"));
debug_println(version);
debug_print(F("Existing CRC16 of 0000-1FFF: "));
debug_println(crc16, HEX);
}

}



int erase_program(uint8_t addr) {
// erase user space
uint8_t data[] = { 0x04 };
uint8_t result = twi_writeTo(addr, data, ELEMENTS(data), true, true);
uint8_t result = write_cmd(addr, data, true);

debug_print(F("Erasing: "));
debug_print_result(result);
debug_print(F("\r\n"));
debug_println_result(result);
if (result != ENDTRANS_SUCCESS) {
_delay_ms(1000);
debug_print(F("failed.\r\n"));
debug_println(F("failed."));
return -1;
}
return 0;
Expand All @@ -153,14 +230,15 @@ int write_firmware(uint8_t addr ) {

// write page addr
uint8_t data[] = { 0x01, (uint8_t)(offsets[o] & 0xff), (uint8_t)(offsets[o] >> 8)};
result = twi_writeTo(addr, data, ELEMENTS(data), true, true);
result = write_cmd(addr, data, true);
debug_print_result(result);
debug_print(F(" - "));

_delay_ms(DELAY);
// got something other than ACK. Start over.
if (result != ENDTRANS_SUCCESS) {
debug_print(F("\r\nFailed\r\n"));
debug_println();
debug_println(F("Failed"));
return -1;
}

Expand All @@ -187,19 +265,20 @@ int write_firmware(uint8_t addr ) {
data[data_counter++] = (uint8_t)(crc16 >> 8);
data[data_counter++] = (0x00); // dummy end uint8_t

result = twi_writeTo(addr, data, ELEMENTS(data), true, true);
result = write_cmd(addr, data, true);
debug_print(F(" "));
debug_print(frame);
debug_print(F(" of 4: "));
// got something other than NACK. Start over.
if (result != ENDTRANS_DATA_NACK) {
debug_print(F("\nERROR: Got something other than NACK\n") );
debug_println();
debug_println(F("ERROR: Got something other than NACK"));
return -1;
}
debug_print(F("OK;"));
delay(DELAY);
}
debug_print(F("\r\n"));
debug_println();
o++;
}
return 0;
Expand All @@ -209,7 +288,7 @@ int write_firmware(uint8_t addr ) {
int verify_firmware(byte addr) {
byte result = ENDTRANS_DATA_NACK;
// verify firmware
debug_print(F("Verifying install\r\n"));
debug_println(F("Verifying install"));
while (result != ENDTRANS_SUCCESS) {
debug_print(F("CRC16 "));

Expand All @@ -218,22 +297,20 @@ int verify_firmware(byte addr) {
// skip the first 4 bytes, are they were probably overwritten by the reset vector preservation
result = read_crc16(addr, &version, &crc16, offsets[0] + 4, firmware_length - 4);

debug_print_result(result);
debug_print(F("\r\n"));
debug_println_result(result);

if (result != ENDTRANS_SUCCESS) {
_delay_ms(100);
continue;
}
debug_print(F("Version: "));
debug_print(version);
debug_print(F("\r\nCRC16 of "));
debug_println(version);
debug_print(F("CRC16 of "));
debug_print(offsets[0] + 4, HEX);
debug_print(F("-"));
debug_print(offsets[0] + firmware_length, HEX);
debug_print(F(": "));
debug_print(crc16, HEX);
debug_print(F("\r\n"));
debug_println(crc16, HEX);
// calculate our own CRC16
uint16_t check_crc16 = 0xffff;
for (uint16_t i = 4; i < firmware_length; i++) {
Expand All @@ -244,43 +321,40 @@ int verify_firmware(byte addr) {
debug_print(check_crc16, HEX);
return -1;
}
debug_print(F("OK\r\n"));
debug_println(F("OK"));
}
return 0;
}

byte update_attiny(byte addr) {
debug_print(F("Communicating\r\n"));
debug_println(F("Communicating"));

get_version(addr);

int erased = erase_program(addr);

if (erased == -1) {

return 0;
}

int firmware_written = write_firmware(addr);
if(firmware_written == -1) {
debug_print(F("Write failed.\r\n"));
if (firmware_written == -1) {
debug_println(F("Write failed."));
return 0;
}

int firmware_verified = verify_firmware(addr);
if(firmware_verified == -1) {
debug_print(F("Verify failed.\r\n"));
if (firmware_verified == -1) {
debug_println(F("Verify failed."));
return 0;
}

debug_print(F("Resetting ATTiny "));

// execute app
uint8_t data[] = {0x03, 0x00};
uint8_t result = twi_writeTo(addr, data, ELEMENTS(data), true, true);
debug_print_result(result);
debug_print(F("\r\n"));
debug_print(F("Done!\r\n"));
uint8_t result = write_cmd(addr, data, true);
debug_println_result(result);
debug_println(F("Done!"));

return 1;
}
Expand All @@ -291,32 +365,36 @@ int right_written = 0;
void loop() {
delay(2000);

if (left_written > 0) {
debug_print(F("Done with left side.\r\n"));
// Update right side first, because resetting it will power-cycle
// LEDs on both sides.
if (right_written > 0) {
debug_println(F("Done with right side."));
leds_success(RIGHT_LEDS);
// we're done
} else {
debug_print(F("Updating left side\r\n"));
reset_left_attiny();
left_written = update_attiny(LEFT_ADDRESS);

debug_println(F("Updating right side"));
reset_right_attiny();
right_written = update_attiny(RIGHT_ADDRESS);
delay(3 * RESET_DELAY);
leds_success(RIGHT_LEDS);
}

if (right_written > 0) {
debug_print(F("Done with right side.\r\n"));
if (left_written > 0) {
debug_println(F("Done with left side."));
leds_success(LEFT_LEDS);
// we're done
} else {
debug_print(F("Updating right side\r\n"));
reset_right_attiny();
right_written = update_attiny(RIGHT_ADDRESS);
debug_println(F("Updating left side"));
reset_left_attiny();
left_written = update_attiny(LEFT_ADDRESS);
delay(3 * RESET_DELAY);
leds_success(LEFT_LEDS);
}

if (left_written && right_written ) {
debug_print (F("Both ATTiny MCUs have been flashed\r\nIt is now safe to reload the regular firmware\r\n"));
debug_println(F("Both ATTiny MCUs have been flashed"));
debug_println(F("It is now safe to reload the regular firmware"));
delay(5000);
return;
}


}


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