introduce new feature: BOOTLOADER_HIDDENEXITCOMMAND

With this "BOOTLOADER_HIDDENEXITCOMMAND" feature, sending the RAW-ISP
command "11111111 xxxxxxxx xxxxxxxx xxxxxxxx" will cause the bootloader
to start the firmware as soon as the programming software disconnects.

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>

firmware/bootloaderconfig.h

@@ -322,6 +322,18 @@ these macros are defined, the boot loader usees them.
  * user intervention
  */
 
+#ifdef CONFIG_NO__BOOTLOADER_HIDDENEXITCOMMAND
+#	define HAVE_BOOTLOADER_HIDDENEXITCOMMAND 0
+#else
+#	define HAVE_BOOTLOADER_HIDDENEXITCOMMAND 0xff
+#endif
+/* 
+ * When enabling "BOOTLOADER_HIDDENEXITCOMMAND", then
+ * sending the RAW-ISP command "0xff 0xXX 0xXX 0xXX"
+ * will cause the bootloader to start the firmware
+ * as soon as the programming software disconnects.
+ */
+
 //#define SIGNATURE_BYTES             0x1e, 0x93, 0x07, 0     /* ATMega8 */
 /* This macro defines the signature bytes returned by the emulated USBasp to
  * the programmer software. They should match the actual device at least in

firmware/main.c

@@ -406,6 +406,23 @@ defined (__AVR_ATmega2561__)
 	  sei();
 #   endif
       }
+#endif
+#if (HAVE_BOOTLOADER_HIDDENEXITCOMMAND)
+#	if ((HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0xac) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x20) && (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x28) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x40) && (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x48) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x4c) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0xa0) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0xc0) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x58) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x5c) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x30) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0xac) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x50) && (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x58) && \
+	    (HAVE_BOOTLOADER_HIDDENEXITCOMMAND != 0x38))
+  }else if(rq->wValue.bytes[0] == (HAVE_BOOTLOADER_HIDDENEXITCOMMAND)){  /* cause a bootLoaderExit at disconnect */
+      stayinloader = 0xf1;  /* we need to be connected - so assume it */
+#	endif
 #endif
   }else{
       /* ignore all others, return default value == 0 */