Hello,
I am having some trouble understanding what bootloader (if any) is installed by ST from the factory for the STM32U5x and what AES key sizes that bootloader supports for secure firmware update. UM2851 only lists AES-CTR-128 (I interpret 128 to be the key size) but mcuboot docs lists support for 256-bit keys.
Ultimately, I need to be able to encrypt my software using a 256-bit AES key. Is this possible with STM32U5A5 and the ST provided tooling? If so, is there documentation describing how to achieve this configuration?
Thank you
