Don't run user application in the bootloader unless a valid app is present (thanks...

[pub/USBasp.git] / Bootloaders / CDC / BootloaderCDC.c

diff --git a/Bootloaders/CDC/BootloaderCDC.c b/Bootloaders/CDC/BootloaderCDC.c
index f66a483..c7eeb92 100644 (file)
--- a/Bootloaders/CDC/BootloaderCDC.c
+++ b/Bootloaders/CDC/BootloaderCDC.c
@@ -91,6 +91,10 @@ void Application_Jump_Check(void)
        if ((MCUSR & (1 << WDRF)) && (MagicBootKey == MAGIC_BOOT_KEY))
          JumpToApplication |= true;
 
+       /* Don't run the user application if the reset vector is blank (no app loaded) */
+       if (pgm_read_word_near(0) == 0xFFFF)
+         JumpToApplication = false;
+
        /* If a request has been made to jump to the user application, honor it */
        if (JumpToApplication)
        {