Is possible to programm the STM32f051 through RS485 or UART?

[SAbis]

I am designing right now using STM32051. Using the only SPI interface for my project, I am struggling how to use the NSS for two slave, that the chip give me only one NSS.

It is possible to load my Programm to the chip using the RS485? How could I realise it throug hardware and avoiding the Debuging interface?

[Tesla DeLorean]

I don't think the ROM loader will support RS485 connectivity, but if you have your own small loader familiar with your hardware configuration/behaviour, you can make it flash the rest of the memory with your own application.

[SAbis]

Hi, how could i get my own loader? I am really new with STM32F0 or Controller. but i want to update my firmware through RS485 or UART but how shall i configure me µC pin to get it? how shall i configure my Boot-Pin in this case? what about my SWD (serial wired debugging)?

Thanks for my your Help