TF-M NV Counters API

[jeremyherbert]

Hi,

Is it correct that nrf-sdk does not support (or have any implementation for) the "NV Counters" API in TF-M ? (needed for rollback protection in the Protected Storage service).

Thanks,

Jeremy

[jeremyherbert]

Hi Dejan,

I ended up checking with the TF-M mailing list and indeed the external protected storage (PS - PSS was a typo sorry) is limited by the flash endurance of a single page in the internal flash regardless of the endurance of external storage, which is 10k writes for the nrf53/nrf91. So after 10k writes, one must assume that the NV counters fail to zero and then the various rollback protections in TF-M will then fail insecure.

Thanks,

Jeremy