FreeRTOS Microvisor Sample Project

This repo provides a basic demonstration of user application firmware based on the FreeRTOS real-time operating system and which will run on the “non-secure” side of Microvisor.

The ARM CMSIS-RTOS API is used an an intermediary between the application and FreeRTOS to make it easier to swap out the RTOS layer for another.

Most of the project files can be found in the Demo/ directory. The ST_Code/ directory contains required components that are not part of Twilio Microvisor STM32U5 HAL, which this sample accesses as a submodule. FreeRTOS is also incorporated as a submodule.

The FreeRTOSConfig.h and stm32u5xx_hal_conf.h configuration files are located in the Config/ directory.

The sample code toggles GPIO PA5, which is the user LED on the Microvisor Nucleo Development Board. It also emits a “ping” to the Microvisor logger once a second.

Platform Support

We currently support the following build platforms:

Linux — native development under Ubuntu 20.0.4.
Windows — development in Ubuntu 20.0.4 via Windows Subsystem for Linux 2.
Mac — development via Docker container.

Build under Windows

The recommended solution for working with Microvisor on Windows is via Windows Subsystem for Linux (WSL).

You will need Administrator privileges to install WSL.

Install WSL

Open an Administrator-level Powershell instance.
Run wsl --install -d ubuntu.
Open the Ubuntu instance shell from your Start menu and follow the Ubuntu instructions below.

Build with Docker

Build the image:

docker build --build-arg UID=$(id -u) --build-arg GID=$(id -g) -t microvisor-freertos-image .

Run the build:

docker run -it --rm -v $(pwd)/:/home/mvisor/project/ \
  --env-file env.list \
  --name microvisor-freertos microvisor-freertos-image

Under Docker, the demo is compiled, uploaded and deployed to your development board. It also initiates logging — hit ctrl-c to break out to the command prompt.

Build in Ubuntu

Install Libraries and Tools

Under Ubuntu, run the following:

sudo apt install gcc-arm-none-eabi binutils-arm-none-eabi \
  git curl build-essential cmake libsecret-1-dev jq openssl

Twilio CLI

Install the Twilio CLI. This is required to view streamed logs and for remote debugging. You need version 4.0.1 or above.

Note If you have already installed the Twilio CLI using npm, we recommend removing it and then reinstalling as outlined below. Remove the old version with npm remove -g twilio-cli.

wget -qO- https://twilio-cli-prod.s3.amazonaws.com/twilio_pub.asc | sudo apt-key add -
sudo touch /etc/apt/sources.list.d/twilio.list
echo 'deb https://twilio-cli-prod.s3.amazonaws.com/apt/ /' | sudo tee /etc/apt/sources.list.d/twilio.list
sudo apt update
sudo apt install -y twilio

Close your terminal window or tab, and open a new one. Now run:

twilio plugins:install @twilio/plugin-microvisor

The process outlined below requires Plugin 0.3.10 or above.

Set Environment Variables

Running the Twilio CLI and the Microvisor Plugin for uploading the built code to the Twilio cloud and subsequent deployment to your Microvisor Nucleo Board uses the following Twilio credentials stored as environment variables. They should be added to your shell profile:

export TWILIO_ACCOUNT_SID=ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
export TWILIO_AUTH_TOKEN=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
export MV_DEVICE_SID=UVxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

You can get the first two from your Twilio Console account dashboard.

Enter the following command to get your target device’s SID and, if set, its unique name:

twilio api:microvisor:v1:devices:list

It is also accessible via the QR code on the back of your development board. Scan the code with your mobile phone and a suitable app, and the board’s SID is the third /-separated field.

Build and Deploy the Demo

cd twilio-microvisor-freertos
twilio microvisor:deploy . --devicesid ${MV_DEVICE_SID} --log

This will compile, bundle and upload the code, and stage it for deployment to your device. If you encounter errors, please check your stored Twilio credentials.

The --log flag initiates log-streaming.

View Log Output

You can start log streaming without first building and/or deploying new code with this command:

twilio microvisor:deploy . --devicesid ${MV_DEVICE_SID} --logonly

You can build but not deploy with this command:

twilio microvisor:deploy . --build

You can deploy the most recent build with this command:

twilio microvisor:deploy . --device-sid ${MV_DEVICE_SID} --deploy

You can clean the most build directory before compiling with this command:

twilio microvisor:deploy . --device-sid ${MV_DEVICE_SID} --clean

For more information, run:

twilio microvisor:deploy --help

Repo Updates

Update the repo’s submodules to their remotes’ latest commits with:

cd /path/to/twilio-microvisor-freertos
git submodule update --init --remote --recursive

twilio / twilio-microvisor-freertos