- usb/usb.h, usb/atu2.c (usb_reset): reset the USB bus by detaching and
re-attaching the device
- boot.c (main): force a USB reset before running the payload
- usb/atu2.c (usb_poll): test for USB reset from the host (in progress)
- usb/dfu.c (my_reset, dfu_init): register user USB reset handler
- boot.c: basic boot loader that runs DFU for 2 s, then starts the payload
- board.h (DFU_USB_VENDOR, DFU_USB_PRODUCT): added USB IDs for DFU
- flash.c: stubs for board-specific Flash functions
- Makefile: build boot.hex for the boot loader
- Makefile (prog): load the boot loader at its rightful place
- Makefile (prog): also set hfuse and the lock fuse