X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/1a4a26271e32fba6e2430b7869ec4a8b4242e6e2..0da99447d3e88e83f9977501bee56af5c7aa56c0:/Bootloaders/CDC/BootloaderCDC.c?ds=sidebyside diff --git a/Bootloaders/CDC/BootloaderCDC.c b/Bootloaders/CDC/BootloaderCDC.c index f336a1368..af778c76f 100644 --- a/Bootloaders/CDC/BootloaderCDC.c +++ b/Bootloaders/CDC/BootloaderCDC.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 @@ -56,6 +56,55 @@ static uint32_t CurrAddress; */ static 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; + + +/** 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_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)) + JumpToApplication |= true; + + /* If a request has been made to jump to the user application, honor it */ + if (JumpToApplication) + { + /* Turn off the watchdog */ + MCUSR &= ~(1<