What is the purpose of JP1? It connects to the STLINK MCU, and via two solder-jumpers on the bottom of the board (SB14,15) to PA9,10 of the 'F051 (the USART-1 pins). Can the STLINK enumerate as a CDC endpoint, and thus provide a serial port for the 'F0? Or, perhaps it is there to explore the built-in hardware bootloader (again enumerated as a CDC endpoint)? If either of these speculations is true, would the STLINK MCU first need to be re-programmed as a CDC device via the DFU loader?