Hi Minos,

What are the use cases for Application Root of Trust services that need NV counters?

The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.

Adrian
From: TF-M <tf-m-bounces@lists.trustedfirmware.org> on behalf of Minos Galanakis via TF-M <tf-m@lists.trustedfirmware.org>
Sent: 22 January 2020 17:28
To: tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.org>
Cc: nd <nd@arm.com>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
 

Hi,

The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.

This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.

This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.

All input, question or comments are greatly appreciated.

Minos


IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.