I am using USB CDC both for bootloader and in the loaded application with the IAR toolset and the CubeMX Middleware/HALlibrary. Turning off the USB & Timer interrupts before the jump it jumps cleanly and runs the application, except that the USB will not restart (USBD_Start). I am using the normal start USBD start sequence. If I load the application and run it at the same address all is fine and USB initialises runs as expected. Is there a prescribed way to turn off USB in the boot loader and re-start it in an application?