I have a doubt. Suppose we have few components like external RAM, external flash etc and we don’t need them as part of bootloader, Do you set anything for those components GPIO pins (for example set them analog input) or just ignore them?
In one of my project I was using external flash W25Q80 and whenever I use to flash a program which doesn’t include GPIO initialization for same component, External flash used to stop working from next time. Don’t know if that make any sense.
Also you have motioned that STM has few scratch registers for mailbox. Can you please name them ?