For some devices EEPROM may occupies half the total flash size

[marshfolx]

Not sure if I understand it correctly: EEPROM library always uses the last sector of flash, and erase the entire sector when eeprom_buffered_flush() is called.

I'm using STM32F410rb, and its flash is orgnaized as follow:

The last sector is 64kB, which is erased by EEPROM, and my code can only use the lower 64kB of flash. My questions:

1. Is there any check existing so that if code size exeeceding the limit, any sort of error or warning will be raised?
2. Any way to use smaller sector as eeprom?

I found a solution using a constant array to tell compiler where the eeprom sector is. Then compiler will put code outside this area, and the code size limit because of the usage of EEPROM is visible.

But when I don't use EEPROM, I wonder if the array will still be there, costing my flash space?

[fpistm]

Hi,

1. Is there any check existing so that if code size exeeceding the limit, any sort of error or warning will be raised?

No check done.

2. Any way to use smaller sector as eeprom?

Yes you can redefine some definitions, mainly FLASH_BASE_ADDRESS using the build_opt.h:
https://github.com/stm32duino/Arduino_Core_STM32/blob/main/libraries/EEPROM/src/utility/stm32_eeprom.c#L93-L94