Need a way to make firmware upgrade

Your approach makes sense. Separating the boot or flash management code from the main application is a common design because it allows you to update the application while keeping the flash management logic intact. Jumping to the application's start address after validating the firmware is also a typical technique, although you'll want to ensure the stack pointer, interrupt vectors, and processor state are correctly initialized before transferring execution. Proper version checking and integrity verification can help prevent corrupted firmware from being executed.

I also like your idea of maintaining version information in flash, as it simplifies future updates and rollback strategies. The overall design reminds me of applications that process structured information, where validation is just as important as execution. Whether you're implementing decodifica codice fiscale to interpret encoded data or building a tool that genera codice fiscale according to predefined rules, careful validation and consistency checks are essential for producing reliable results.