jump.c

#include "jump.h"

#include <avr/wdt.h>
#include <avr/eeprom.h>

uint16_t boot_key __attribute__((section (".noinit")));
const uint8_t *valid_app_addr = (uint8_t *) (E2END - BOOTLOADER_EEPROM_SIZE);

void jump_check (void)
{
  uint8_t valid_app = 0;

  /* Check to see if we should read BLE data from EEPROM */
  valid_app = eeprom_read_byte (valid_app_addr);

  if ((MCUSR & (1 << WDRF)) &&
      (boot_key == BOOTLOADER_KEY) &&
      valid_app == 1)
  {
    /* Clear watchdog reset flag and the boot key */
    MCUSR &= ~(1 << WDRF);
    boot_key = 0;

    /* Disable watchdog */
    WDTCSR = _BV(WDCE) | _BV(WDE);
    WDTCSR = 0;

    /* Jump to application */
    ((void (*)(void)) 0x0000)();
  }
}

void jump_boot_key_clear (void)
{
  boot_key = 0;
}

void jump_boot_key_set (void)
{
  boot_key = BOOTLOADER_KEY;
}

void jump_app_key_clear (void)
{
  eeprom_write_byte ((uint8_t *)valid_app_addr, 0);
}

void jump_app_key_set (void)
{
  eeprom_write_byte ((uint8_t *)valid_app_addr, 1);
}