/*
LUFA Library
- Copyright (C) Dean Camera, 2013.
+ Copyright (C) Dean Camera, 2018.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
- Copyright 2013 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+ Copyright 2018 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
* 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);
+ PORTC |= (1 << 7);
Delay_MS(10);
/* If IO13 is not jumpered to ground, start the user application instead */
- JumpToApplication |= ((PINC & (1 << 7)) != 0);
+ JumpToApplication = ((PINC & (1 << 7)) != 0);
/* Disable pull-up after the check has completed */
PORTC &= ~(1 << 7);
Delay_MS(10);
/* If the TCK pin is not jumpered to ground, start the user application instead */
- JumpToApplication |= ((PINF & (1 << 4)) != 0);
+ JumpToApplication = ((PINF & (1 << 4)) != 0);
/* Re-enable JTAG debugging */
JTAG_ENABLE();
+ #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 */
+ if ((MCUSR & (1 << WDRF)) && (MagicBootKey == MAGIC_BOOT_KEY))
+ JumpToApplication = true;
+
+ /* Clear reset source */
+ MCUSR &= ~(1 << WDRF);
+ }
#endif
- if (JumpToApplication)
+ /* Don't run the user application if the reset vector is blank (no app loaded) */
+ bool ApplicationValid = (pgm_read_word_near(0) != 0xFFFF);
+
+ /* If a request has been made to jump to the user application, honor it */
+ 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)();
}
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
GlobalInterruptEnable();
- for (;;)
+ while (RunBootloader || TicksSinceLastCommand++ < 0xFF)
{
MS_Device_USBTask(&Disk_MS_Interface);
USB_USBTask();
}
+
+ /* Wait a short time to end all USB transactions and then disconnect */
+ _delay_us(1000);
+
+ /* 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;
}
projects / pub / USBasp.git / blobdiff