STM32F030 hardware flash backup

@Home I had Nextion LCD
It is having some bad software that is working on windows only
I was not able to find a way to use interrupt on some pins.
So I was thinking about uploading my code on STM32 to test it out.
But Nextion does not provide factory flash for this display so if I change firmware I cannot get back.

Well I can if I replace chip with new one and put original in safe place (hardware backup) ;)

Next step would be to put something on STM32 and to test it…

Now only need screen pinout :)