Deploying trusted services in S-EL0 Secure Partitions under OP-TEE

Trusted services built for the opteesp environment may be deployed to run within S-EL0 secure partitions, managed by OP-TEE. The current implementation of the OP-TEE SPMC supports booting SPs embedded into the OP-TEE OS binary (similar to early-TAs) or from the FIP.

Tool prerequisites and general build instruction for OP-TEE are described here: https://optee.readthedocs.io/en/latest/building/gits/build.html

Download page for Arm Fixed Virtual Platforms (FVP): https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms

Embedding SP images into the OP-TEE OS image

The set of SP images to include in the built OP-TEE OS image are specified to the OP-TEE OS build by the SP_PATHS make variable. The SP_PATHS variable should be assigned a string containing a space separated list of file paths for each SP image file to include. SP images that need to be deployed from the Trusted Services project will be located in the install directory, specified when the SP images where built i.e.:

<CMAKE_INSTALL_PREFIX>/opteesp/bin

The following example illustrates a setting of the SP_PATHS variable to deploy the Secure Storage SP and Crypto SP:

SP_PATHS="ts-install-dir/opteesp/bin/dc1eef48-b17a-4ccf-ac8b-dfcff7711b14.stripped.elf \
    ts-install-dir/opteesp/bin/d9df52d5-16a2-4bb2-9aa4-d26d3b84e8c0.stripped.elf"

Reference OP-TEE build with PSA RoT Services

To provide an example integration of OP-TEE with a set of trusted services, a makefile called fvp-ps-sp.mk is included in the OP-TEE build repository that builds OP-TEE OS with a set of SP images. SP images are built using the standard trusted services build flow and are automatically injected into the optee_os build using the TA feature described above.

A bootable Linux image is created that is intended to run on the Arm AEM FVP virtual platform. The built image includes user space programs that may be used to test and demonstrate the deployed trusted services.

Getting build dependencies

To help setup the workspace, a manifest file called fvp-ts.xml is included in OP-TEE manifests repository. This may be used with the repo tool to manage the set of git repositories.

Having created a new directory for the workspace, the required set of git repositories can be cloned and fetched using:

repo init -u https://github.com/OP-TEE/manifest.git -b master -m fvp-ts.xml
repo sync

Building the reference OP-TEE image

To build the bootable image that includes OP-TEE and the set of secure partition images that hold the PSA RoT services, use the following (from the root directory of the workspace):

make -C build

This will take many tens of minutes to complete.

Running the reference OP-TEE image on FVP

The fvp makefile includes a run and run-only target which can be used to start the FVP model and boot the built image. The example assumes that the FVP model has been installed in the following directory relative to the OP-TEE build directory:

../Base_RevC_AEMvA_pkg/models/Linux64_GCC-9.3

To boot the built image on FVP without building, use:

FVP_PATH=../Base_RevC_AEMvA_pkg/models/Linux64_GCC-9.3 make run-only

For information on running user space programs on FVP, see:

Running user-space programs on FVP

SPDX-License-Identifier: BSD-3-Clause