/** Flag to indicate if the bootloader should be running, or should exit and allow the application code to run
* via a soft reset. When cleared, the bootloader will abort, the USB interface will shut down and the application
* jumped to via an indirect jump to location 0x0000 (or other location specified by the host).
+ * Use volatile to prevent compiler to do optimization, because we change this variable from interrupt context.
*/
-static bool RunBootloader = true;
+static volatile bool RunBootloader = true;
/** Flag to indicate if the bootloader is waiting to exit. When the host requests the bootloader to exit and
* jump to the application address it specifies, it sends two sequential commands which must be properly
*/
static bool WaitForExit = false;
+/** Minimum time in seconds stay forced into bootloader mode before application will be started. This especially
+ * helpful if the application does not support any update or reflashing or jumping back into bootloader. It prevents
+ * to brick the device if now ISP programmer is available.
+ */
+#ifndef BL_TIME
+#define BL_TIME 5 /* seconds */
+#endif
+
+/** Minimum time ticks stay in bootloader before application is started or negative value to prevent leaving
+ * bootloader. Timer 1 is a 16 bit timer, which overflows after 65536 cycles if it is load with zero. The
+ * timer 1 prescaler is programmed to divide by 64 and the prescaler engine uses a clock_div_1 divisor, means
+ * no divisor of the CPU clock frequency F_CPU.
+ */
+static int8_t ForceBootloaderTime = ((BL_TIME) > 0) ? (F_CPU / 64 * (BL_TIME) / 65536 + 1) : -1;
+
/** Current DFU state machine state, one of the values in the DFU_State_t enum. */
static uint8_t DFU_State = dfuIDLE;
/* Re-enable JTAG debugging */
JTAG_ENABLE();
+ #elif ((BOARD == BOARD_PROMICRO) || (BOARD == BOARD_MICRO))
+ /* Pro-Micro and Arduino Micro board use power-on reset, but no external reset. Both boards have
+ * the hardware bootloader pin HWBE enabled. Unfortunately only the external reset allows together
+ * with an enabled HWBE that the CPU start at the bootloader address independent of the FUSE_BOOTRST.
+ * That means the power-on reset will start just controlled by the FUSE_BOOTRST the bootloader or
+ * direct in the application and cannot be overridden by HWBE signal. Therfore FUSE_BOOTRST shall
+ * be enabled, otherwise the bootloader will not be reached for these boards.
+ * The bootloader checks FUSE_HWBE as *unprogammed* instead of FUSE_BOOTRST as programmed on other
+ * board variants to decide fast application start, without waiting the dedicted bootloader timeout
+ * in case of a USB, watchdog, brown-out or JTAG reset. If the watchdog reset was initiated from
+ * the bootloader marked with the MAGIC_BOOT_KEY this reset flag is reset. All other reset flags
+ * are left untouched to allow the application code checking the reset signals, especially in case
+ * of application fast start.
+ * The bootloader is entered always for external reset and power-on reset. But the bootloader is
+ * anyway exited after that dedicted timeout, if a reset-vector to the application is programmed.
+ * Once a DFU program interacts this the bootloader during this dedicted timeout, the timer stops
+ * and the application needs to be started by DFU bootloader command manually or using a reset.
+ */
+
+ /* Check if the device's forced Bootloader via Hardware Bootenable is unprogrammed */
+ if (BootloaderAPI_ReadFuse(GET_EXTENDED_FUSE_BITS) & ~FUSE_HWBE)
+ {
+ /* If the reset source was not an external or power-on reset jump to the application */
+ if (!(MCUSR & ((1 << EXTRF) || (1 << PORF))))
+ JumpToApplication = true;
+ }
+ /* If the reset source was the bootloader and the key is correct, clear it and jump to the application;
+ * this can happen in the HWBE fuse is set, and the HBE pin is low during the watchdog reset */
+ if ((MCUSR & (1 << WDRF)) && (MagicBootKey == MAGIC_BOOT_KEY))
+ {
+ JumpToApplication = true;
+
+ /* Clear reset source */
+ MCUSR &= ~(1 << WDRF);
+ }
#else
+ /* Check if the device's BOOTRST fuse is set */
+ if (!(BootloaderAPI_ReadFuse(GET_HIGH_FUSE_BITS) & ~FUSE_BOOTRST))
+ {
+ /* If the reset source was not an external reset or the key is correct, clear it and jump to the application */
+ if (!(MCUSR & (1 << EXTRF)) || (MagicBootKey == MAGIC_BOOT_KEY))
+ JumpToApplication = true;
+
+ /* Clear reset source */
+ MCUSR &= ~(1 << EXTRF);
+ }
+ else
{
/* If the reset source was the bootloader and the key is correct, clear it and jump to the application;
* this can happen in the HWBE fuse is set, and the HBE pin is low during the watchdog reset */
}
#endif
+ /* Clear the boot key in any case */
+ MagicBootKey = 0;
+
/* Don't run the user application if the reset vector is blank (no app loaded) */
bool ApplicationValid = (pgm_read_word_near(0) != 0xFFFF);
if (JumpToApplication && ApplicationValid)
{
/* Turn off the watchdog */
- MCUSR &= ~(1 << WDRF);
wdt_disable();
- /* Clear the boot key and jump to the user application */
- MagicBootKey = 0;
-
// cppcheck-suppress constStatement
((void (*)(void))0x0000)();
}
}
-
-static volatile bool stayinbootloader;
-
/** Main program entry point. This routine configures the hardware required by the bootloader, then continuously
* runs the bootloader processing routine until instructed to soft-exit, or hard-reset via the watchdog to start
* the loaded application code.
SetupHardware();
/* Turn on first LED on the board to indicate that the bootloader has started */
- //LEDs_SetAllLEDs(LEDS_LED1);
+ LEDs_SetAllLEDs(LEDS_LED1);
/* Enable global interrupts so that the USB stack can function */
GlobalInterruptEnable();
/* Run the USB management task while the bootloader is supposed to be running */
- /*if bit_is_clear(PINB,PB5) // PB5 is Digital 9 on Arduino Pro Micro
- {
- loop_until_bit_is_set(PINB,PB5);
-
- while ((RunBootloader || WaitForExit) && bit_is_set(PINB,PB5))
- USB_USBTask();
-
- loop_until_bit_is_clear(PINB,PB5);
- }*/
-
- stayinbootloader = false;
-
- uint16_t i = 0;
while (RunBootloader || WaitForExit)
- {
- USB_USBTask();
-
- if (!stayinbootloader)
- {
- _delay_ms(1);
- if (i++ > 5000)
- {
- break;
- }
- }
- else
- {
- i = 0;
- }
- }
+ USB_USBTask();
/* Wait a short time to end all USB transactions and then disconnect */
_delay_us(1000);
/* Initialize the USB and other board hardware drivers */
USB_Init();
- //LEDs_Init();
- DDRB = 1;
- PORTB = _BV(PB5);
- DDRD = 0b00100000;
- PORTD = 0;
+ LEDs_Init();
/* Bootloader active LED toggle timer initialization */
TIMSK1 = (1 << TOIE1);
+ /* config timer 1 prescaler to F_CPU / clock_div_1 / 64 */
TCCR1B = ((1 << CS11) | (1 << CS10));
}
{
/* Shut down the USB and other board hardware drivers */
USB_Disable();
- //LEDs_Disable();
- DDRB = 0;
- PORTB = 0;
- DDRD = 0;
- PORTD = 0;
+ LEDs_Disable();
/* Disable Bootloader active LED toggle timer */
TIMSK1 = 0;
/** ISR to periodically toggle the LEDs on the board to indicate that the bootloader is active. */
ISR(TIMER1_OVF_vect, ISR_BLOCK)
{
- //LEDs_ToggleLEDs(LEDS_LED1 | LEDS_LED2);
- PORTB &= ~_BV(PB0);
- _delay_ms(5);
- PORTB |= _BV(PB0);
+ LEDs_ToggleLEDs(LEDS_LED1 | LEDS_LED2);
+ /* Count number for forced ticks not below zero */
+ if (ForceBootloaderTime > 0)
+ ForceBootloaderTime--;
+ /* check if it is time to leave the bootloader and a valid application exists */
+ if ((ForceBootloaderTime == 0) && (pgm_read_word_near(0) != 0xFFFF))
+ RunBootloader = false;
}
/** Event handler for the USB_ControlRequest event. This is used to catch and process control requests sent to
return;
}
-stayinbootloader = true;
+ /* prevent counter to reach zero */
+ ForceBootloaderTime = -1;
/* Activity - toggle indicator LEDs */
- //LEDs_ToggleLEDs(LEDS_LED1 | LEDS_LED2);
- PORTB &= ~_BV(PB0);
- _delay_ms(5);
- PORTB |= _BV(PB0);
+ LEDs_ToggleLEDs(LEDS_LED1 | LEDS_LED2);
/* Get the size of the command and data from the wLength value */
SentCommand.DataSize = USB_ControlRequest.wLength;
else // Start via jump
{
/* Set the flag to terminate the bootloader at next opportunity if a valid application has been loaded */
- if (pgm_read_word_near(0) == 0xFFFF)
+ if (pgm_read_word_near(0) != 0xFFFF)
RunBootloader = false;
}
}
projects / pub / lufa.git / blobdiff