Hi Reinhard,

This is correct at current and needs SFC specification to clarification in future.

The existing PSA Firmware Framework proposes a thread based Secure Partition and the IPC manner about how the information is shared between these process.

The SFC model (which is a well know model but do not have a specification yet) combines secure services as a library and makes the information-sharing mechanism complicate under isolation level 2/3, which lost the advantage of ‘library’ model.

/Ken

From: TF-M <tf-m-bounces@lists.trustedfirmware.org> On Behalf Of Reinhard Keil via TF-M
Sent: Tuesday, December 17, 2019 4:10 PM
To: tf-m@lists.trustedfirmware.org
Subject: [TF-M] Level 2/Level 3 Isolation requires IPC?

I have heard that Level 2/Level 3 isolation with TF-M requires Inter-Process Communication (IPC) mode.

It does not work with Secure Function Call (SFC) mode (aka Library mode).

Is it correct, and why does Level2/Level 3 isolation require IPC?

Reinhard

_______________________________________________________________________________

Reinhard Keil  |  Phone: +49 89 456040-13  |  Email: reinhard.keil@arm.com  | www.keil.com

ARM Germany GmbH  |  Bretonischer Ring 16  |  D-85630 Grasbrunn,Germany

Sitz der Gesellschaft: Grasbrunn  |  Handelsregister: München (HRB 175362)

Geschäftsführer: Andrew Smith, Joachim Krech, Reinhard Keil

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.