samples: psa: its: add the psa_its sample

    - tomi-font

  files:

    - subsys/secure_storage/

    - samples/psa/

    - tests/subsys/secure_storage/

  labels:

    - "area: Secure storage"

.. zephyr:code-sample-category:: psa

   :name: PSA

   :show-listing:

   The following samples demonstrate various uses of several of the

   `Platform Security Architecture (PSA) Certified APIs <https://arm-software.github.io/psa-api/>`_.

# SPDX-License-Identifier: Apache-2.0

cmake_minimum_required(VERSION 3.20.0)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})

project(psa_its)

target_sources(app PRIVATE src/main.c)

.. zephyr:code-sample:: psa_its

   :name: PSA Internal Trusted Storage API

   :relevant-api: psa_secure_storage

   Use the PSA ITS API.

Overview

********

This sample demonstrates usage of the

`PSA Internal Trusted Storage (ITS) API <https://arm-software.github.io/psa-api/storage/1.0/overview/architecture.html#the-internal-trusted-storage-api>`_,

which is part of the `PSA Secure Storage API <https://arm-software.github.io/psa-api/storage/>`_,

for storing and retrieving persistent data.

Requirements

************

An implementation of the PSA ITS API must be present for this sample to build.

It can be provided by:

* :ref:`tfm`, for ``*/ns`` :term:`board targets<board target>`.

* The :ref:`secure storage subsystem <secure_storage>`, for the other board targets.

Building

********

This sample is located in :zephyr_file:`samples/psa/its`.

Different configurations are defined in the :file:`sample.yaml` file.

You can use them to build the sample, depending on the PSA ITS provider, as follows:

.. tabs::

   .. tab:: TF-M

     For board targets with TF-M:

      .. zephyr-app-commands::

         :zephyr-app: samples/psa/its

         :tool: west

         :goals: build

         :board: <ns_board_target>

         :west-args: -T sample.psa.its.tfm

   .. tab:: secure storage subsystem

      For board targets without TF-M.

      If the board target to compile for has an entropy driver (preferable):

      .. zephyr-app-commands::

         :zephyr-app: samples/psa/its

         :tool: west

         :goals: build

         :board: <board_target>

         :west-args: -T sample.psa.its.secure_storage.entropy_driver

      Or, to use an insecure entropy source (only for testing):

      .. zephyr-app-commands::

         :zephyr-app: samples/psa/its

         :tool: west

         :goals: build

         :board: <board_target>

         :west-args: -T sample.psa.its.secure_storage.entropy_not_secure

To flash it, see :ref:`west-flashing`.

# SPDX-License-Identifier: Apache-2.0

CONFIG_ENTROPY_GENERATOR=y

CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG=y