* Main source file for the Mass Storage class bootloader. This file contains the complete bootloader logic.
*/
+#define INCLUDE_FROM_BOOTLOADER_MASSSTORAGE_C
#include "BootloaderMassStorage.h"
/** LUFA Mass Storage Class driver interface configuration and state information. This structure is
{
.Config =
{
- .InterfaceNumber = 0,
+ .InterfaceNumber = INTERFACE_ID_MassStorage,
.DataINEndpoint =
{
.Address = MASS_STORAGE_IN_EPADDR,
},
};
+/** 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
+ * started via a forced watchdog reset.
+ */
+bool RunBootloader = true;
+
+/** Magic lock for forced application start. If the HWBE fuse is programmed and BOOTRST is unprogrammed, the bootloader
+ * will start if the /HWB line of the AVR is held low and the system is reset. However, if the /HWB line is still held
+ * low when the application attempts to start via a watchdog reset, the bootloader will re-start. If set to the value
+ * \ref MAGIC_BOOT_KEY the special init function \ref Application_Jump_Check() will force the application to start.
+ */
+uint16_t MagicBootKey ATTR_NO_INIT;
+
+/** Indicates if the bootloader is allowed to exit immediately if \ref RunBootloader is \c false. During shutdown all
+ * pending commands must be processed before jumping to the user-application, thus this tracks the main program loop
+ * iterations since a SCSI command from the host was received.
+ */
+static uint8_t TicksSinceLastCommand = 0;
+
+
+/** Special startup routine to check if the bootloader was started via a watchdog reset, and if the magic application
+ * start key has been loaded into \ref MagicBootKey. If the bootloader started via the watchdog and the key is valid,
+ * this will force the user application to start via a software jump.
+ */
+void Application_Jump_Check(void)
+{
+ bool JumpToApplication = false;
+
+ #if (BOARD == BOARD_LEONARDO)
+ /* Enable pull-up on the IO13 pin so we can use it to select the mode */
+ PORTC |= (1 << 7);
+ Delay_MS(10);
+
+ /* If IO13 is not jumpered to ground, start the user application instead */
+ JumpToApplication |= ((PINC & (1 << 7)) != 0);
+
+ /* Disable pull-up after the check has completed */
+ PORTC &= ~(1 << 7);
+ #elif ((BOARD == BOARD_XPLAIN) || (BOARD == BOARD_XPLAIN_REV1))
+ /* Disable JTAG debugging */
+ JTAG_DISABLE();
+
+ /* Enable pull-up on the JTAG TCK pin so we can use it to select the mode */
+ PORTF |= (1 << 4);
+ Delay_MS(10);
+
+ /* If the TCK pin is not jumpered to ground, start the user application instead */
+ JumpToApplication |= ((PINF & (1 << 4)) != 0);
+
+ /* Re-enable JTAG debugging */
+ JTAG_ENABLE();
+ #endif
+
+ /* If the reset source was the bootloader and the key is correct, clear it and jump to the application */
+ if ((MCUSR & (1 << WDRF)) && (MagicBootKey == MAGIC_BOOT_KEY))
+ {
+ MagicBootKey = 0;
+ JumpToApplication = true;
+ }
+
+ if (JumpToApplication)
+ {
+ // cppcheck-suppress constStatement
+ ((void (*)(void))0x0000)();
+ }
+}
/** Main program entry point. This routine configures the hardware required by the application, then
* enters a loop to run the application tasks in sequence.
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
GlobalInterruptEnable();
- for (;;)
+ while (RunBootloader || TicksSinceLastCommand++ < 0xFF)
{
MS_Device_USBTask(&Disk_MS_Interface);
USB_USBTask();
}
+
+ /* Disconnect from the host - USB interface will be reset later along with the AVR */
+ USB_Detach();
+
+ /* Unlock the forced application start mode of the bootloader if it is restarted */
+ MagicBootKey = MAGIC_BOOT_KEY;
+
+ /* Enable the watchdog and force a timeout to reset the AVR */
+ wdt_enable(WDTO_250MS);
+
+ for (;;);
}
/** Configures the board hardware and chip peripherals for the demo's functionality. */
CommandSuccess = SCSI_DecodeSCSICommand(MSInterfaceInfo);
LEDs_SetAllLEDs(LEDMASK_USB_READY);
+ /* Signal that a command was processed, must not exit bootloader yet */
+ TicksSinceLastCommand = 0;
+
return CommandSuccess;
}