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Milestone 1 (Obsolete)

Research and Prototyping


During this milestone research and prototyping was the main focus. Following the original plan, we concentrated on:

  • Reference boards selection and feasibility.
  • Operating system and other critical components
  • Define applicable toolchains ( Rust, C/C++, etc.) and provide a "hello world" example involving Rust and OPTEE
  • Development process: Define CI and Testing strategy.

From an architectural overview, we considered the following aspects:

  • Hardware
  • BSP and Operating System
  • Trusted App (TA) and Host App (Signer Endpoint)
  • Node Endpoint
  • Other artifacts
    • Provisioning process and documentation
    • Image signing tool
    • Documentation


1. Hardware selection

Milestone requirement

Select two hardware platforms (from different providers) to use as a proof-of-concept.

Our decision for M1 is to start development on the following boards. We have mainly prioritized technical support, supply chain, form factor, ethernet availability, latest generation MPU and community.

STM32MP157C-DK2STM32MP157CST Microelectronics

We plan to extend support to the following devices in the following weeks

ModelMPUManufacturerReason for delay
Compulab SBC-iMX8M-Minii.MX8CompulabOPTEE regression test fails. Being diagnosed by Compulab
TechNexion PICO-PI-IMX8Mi.MX8TechNexionZondax is currently testing for compatibility
Verdin iMX8Mi.MX8ToradexDevice is still not available in the market
byteDEVKITSTM32MP157CBytesAtWorkIssues at boot. Discussing with manufacturer at this moment

It is unlikely that we will add support for the following devices:

ModelMPUManufacturerReason for delay
USB Armory Mk-IIi.MX6F-secureInadequate form factor. Lack of ethernet port, etc.
Advantech WISE-710i.MX6AdvantechBSP and support was very low quality
Phytec phyBOARD-Segini.MX6PhytecOPTEE is not supported by the manufacturer
Phytec phyBOARD-Polarisi.MX8PhytecOPTEE is not supported by the manufacturer
Apalis iMX8 QuadMaxi.MX8ToradexOPTEE Support issues. Being discussed with NXP & Toradex

Nevertheless, our implementation will be easy to port to other platforms. We expect the list of supported devices to grow over time.

We provide more details in the following links:

2. Feasibility

Milestone requirement

Minimal implementations for each selected board to demonstrate feasibility.

We provide instructions for the supported platforms here. You will be able to find:

  • How to setup the hardware for a testing and development environment.
  • How to build an image and load it using an SD card
  • How to boot and test "hello_rustee"
    • Hello_Rustee is an OPTEE-based implementation including both trusted and host apps.
    • This is described in the next section.

The following repositories contain the implementation for different components / layers:

Component / layerLink / Repository
Yocto images (build environment, container, CI and manifests)GitHub
Yocto metalayer with specific image customizationGitHub
Build container (build environment, toolchains, qemu)GitHub
HelloRustee - Rust + OPTEE exampleGitHub
Documentation website (frequently being updated)GitHub
Documentation Source codeGitHub

Secure Boot

While we have already significantly simplified most of the development and testing process, there are still some aspects that are specific to each of the boards. In particular, as explained here, secure booting still requires manual steps.

For the time being, we recommend W3F to review the documentation but avoid executing the steps. Mistakes may result in irreversible changes to the boards (one time programming (OTP) fuses). In milestone 2, we will deliver better tooling to simplify this process.

3. Hello World + Development process

Milestone requirement
  • Hello-World examples and basic configuration to demonstrate Secure Boot and TrustZone usage. :::

The current Yocto images contain "hello_rustee" GitHub, an example to demonstrate:

  • A Trusted Application
  • A Host application
  • How hello_rustee is supported in a wide range of devices
  • How we can deploy a fully working app and TA in our custom Yocto image.

The corresponding instructions are available in the testing guide

  • Detailed description of the development and testing process.

  • Corresponding unit and integration tests


Not only, we show how to deploy an example OPTEE TA, but also we have created a set of tools to facilitate the typical development workflow, i.e.:

  • compilation
  • emulation (QEMU) and,
  • testing (unit / integration / CI)

In this section and code example, we demonstrate and explain:

  • How to launch hello_rustee in QEMU
  • How to use Rust in combination with OPTEE
  • How to use no_std Rust in the trusted application
  • How to run unit tests
  • How to run integration tests

The complete source for RusTee can be found here.