X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/f201f6697b7f99b63389509b42112026b8f6f76f..7d65c54eef193f4f6f4391ea9fc62ea8c14a73b2:/Bootloaders/DFU/BootloaderDFU.c

diff --git a/Bootloaders/DFU/BootloaderDFU.c b/Bootloaders/DFU/BootloaderDFU.c
index 094801924..528e8cb0c 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<<WDRF);
+		wdt_disable(); 
+
+		/* Clear the boot key and jump to the user application */
+		MagicBootKey = 0;
+
+		// cppcheck-suppress constStatement
+		((void (*)(void))0x0000)();
+	}
+}
 
 /** 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
@@ -137,7 +165,7 @@ int main(void)
 }
 
 /** Configures all hardware required for the bootloader. */
-void SetupHardware(void)
+static void SetupHardware(void)
 {
 	/* Disable watchdog if enabled by bootloader/fuses */
 	MCUSR &= ~(1 << WDRF);
@@ -150,7 +178,7 @@ void SetupHardware(void)
 	MCUCR = (1 << IVCE);
 	MCUCR = (1 << IVSEL);
 
-	/* Initialize the USB subsystem */
+	/* Initialize the USB and other board hardware drivers */
 	USB_Init();
 	LEDs_Init();
 
@@ -160,10 +188,11 @@ void SetupHardware(void)
 }
 
 /** Resets all configured hardware required for the bootloader back to their original states. */
-void ResetHardware(void)
+static void ResetHardware(void)
 {
-	/* Shut down the USB subsystem */
+	/* Shut down the USB and other board hardware drivers */
 	USB_Disable();
+	LEDs_Disable();
 
 	/* Relocate the interrupt vector table back to the application section */
 	MCUCR = (1 << IVCE);
@@ -694,6 +723,9 @@ 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);
 			}