Question
STM32H743 system bootloader cannot program flash by I2C
It is not a question but info for others.
STM32flash app on RPi can connect to STM32H743 on NUCLEO board (tested on SPI2).
AN2606 says "Bank erase is not working on USART/SPI and I2C" but even page-by-page erase does not work so CPU cannot be programmed.
STM32flash does not show the bootloader version but the NUCLEO was purchased at the end of 2019.
Reading of flash memory works.
