Customer has fitted both to different rev boards and wants to detect the hardware rev based on the processor type that was fitted. both run the same firmware without issue. I'm looking for a way (in firmware) to detect which processor is fitted.

USART1 works as expected from firmware loaded via SWD. However the ST bootloader does not work. It never responds to the initial 0x7F with anything. I have scoped tx and rx and cannot see anything wrong and, as stated above, the UART works under the ...