diff options
Diffstat (limited to 'bootloaders/caterina/src/Caterina.cpp')
| -rw-r--r-- | bootloaders/caterina/src/Caterina.cpp | 251 |
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 (;;) + ; +} |