[TF-M] Clarification on boot seed

Hi, I'm doing a PoC on initial attestation for an university project using a RP2350 board and I'm not really understanding why boot seed is stored in OTP, shouldn't it be a value changing on each boot? Pico SDK conveniently exposes one via a ROM function (rom_get_boot_random).

Another similar doubt I have is w.r.t. implementation id, couldn't it be read from the board id (pico_get_unique_board_id)? Board id is factory programmed in otp so it should actually be unique.

Best Regards,

Augusto Zanellato