how to program four mcu simultaneously ?

[Lkhod.1]

i use stm32f410rb microcontroller. one board contain four stm32f410rb micro controller,

my requirement is load firmware all four microcontroller using single connection(uart bootload or jtag or swd or any other programming method ,) so please suggest appropriate method so i can program all micro controller simultaneously or single connection.

please help me

[TDK]

You can use JTAG to program multiple devices from a single connection.

[Tesla DeLorean]

If you can write software the UART protocol is documented, a windows side app could use multiple COM ports concurrently to send the same of different firmwares.

One could also create a fixture where another MCU w/storage could act as a stand-alone programmer.

I think Segger used to have code/libraries to work with daisy chained JTAG devices. Other companies with specialties in JTAG could likely create a custom solution.

If the firmware is the same,or storable, the MCU's could perhaps program each other.