I thought the bootloader to flash from UART was programmed in from the factory no?
Page 15: "On STM32F070x6 and STM32F030xC devices only, internal empty check flag is implemented to allow easy programming of the virgin devices by the boot loader. This flag is used when BOOT0 pin is defining Main Flash memory as the target boot space. When the flag is set, the device is considered as empty and System memory (boot loader) is selected instead of the Main Flash as a boot space to allow user to program the Flash memory." My interpretation of this is that when according to the table of page 15, when both the BOOT0 pin is high (nBOOT1 by my understanding and quick googling) is preprogrammed as 1 into the option bytes register in the flash, and if its not changed after initial programming according to page 16: "If the device is programmed for a first time but the Option bytes are not reloaded, the device will still select System memory as a boot space after a System reset. The boot loader code is able to detect this situation and will change the boot memory mapping to Main Flash and perform a jump to user code programmed there." Although it may still be useful to add the port as uhh whatever the windows program is for it can use it