X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/f201f6697b7f99b63389509b42112026b8f6f76f..c7344c22ac700dacf55a8dc729111dd7781c5fed:/Bootloaders/DFU/BootloaderDFU.c diff --git a/Bootloaders/DFU/BootloaderDFU.c b/Bootloaders/DFU/BootloaderDFU.c index 094801924..f5c8d170e 100644 --- a/Bootloaders/DFU/BootloaderDFU.c +++ b/Bootloaders/DFU/BootloaderDFU.c @@ -1,13 +1,13 @@ /* LUFA Library - Copyright (C) Dean Camera, 2011. + Copyright (C) Dean Camera, 2012. dean [at] fourwalledcubicle [dot] com www.lufa-lib.org */ /* - Copyright 2011 Dean Camera (dean [at] fourwalledcubicle [dot] com) + Copyright 2012 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 @@ -92,6 +92,34 @@ static uint16_t StartAddr = 0x0000; */ static uint16_t EndAddr = 0x0000; +/** 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. + */ +uint32_t MagicBootKey ATTR_NO_INIT; + + +/** 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) +{ + /* 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)) + { + /* Turn off the watchdog */ + MCUSR &= ~(1< 0xFFFF) @@ -694,6 +727,9 @@ static void ProcessWriteCommand(void) { if (SentCommand.Data[1] == 0x00) // Start via watchdog { + /* Unlock the forced application start mode of the bootloader if it is restarted */ + MagicBootKey = MAGIC_BOOT_KEY; + /* Start the watchdog to reset the AVR once the communications are finalized */ wdt_enable(WDTO_250MS); } @@ -709,7 +745,7 @@ static void ProcessWriteCommand(void) uint32_t CurrFlashAddress = 0; /* Clear the application section of flash */ - while (CurrFlashAddress < BOOT_START_ADDR) + while (CurrFlashAddress < (uint32_t)BOOT_START_ADDR) { boot_page_erase(CurrFlashAddress); boot_spm_busy_wait();