NetX rust integration

This takes the build process and most of the structures from https://github.com/sabaton-systems/threadx-rust/ and builds a ThreadX + NetX variant. Compared to the original we did:

• Fix some UB
• Generate NetX bindings
• Implement simple async executor based on https://github.com/zesterer/pollster
• Implement embedded-nal interface for NetX/Wiced Wifi
• Async interface for buttons

Prerequisites and Tool Installation

All steps below are for Linux.

Update Linux

sudo apt update
sudo apt upgrade

Install Arm GCC

sudo apt install gcc-arm-none-eabi
sudo apt install build-essential

Install pkgconf

sudo apt install pkgconf

Install Rust tools

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Close your Linux shell and open it again to update environment variables.

Install dependencies

1. flip-link:

   cargo install flip-link

2. Rust target (for MXAZ3166):

   rustup target add thumbv7m-none-eabi
   rustup target add thumbv7em-none-eabihf

3. Other dependencies:

   sudo apt install ninja-build libclang-dev cmake usbutils

4. Probe-RS to flash the board:

   sudo apt-get install libudev-dev
   cargo install probe-rs-tools

Allow access to debug probe-rs-tools

Follow instructions from probe.rs Linux udev rules

Quickstart

Executor example

The executor.rsexample switches between 2 screens via tha A button and shows either a welcome screen or the actual temperature. It is a demonstration of the async executor based on ThreadX EventFlags.

Goto threadx-app/cross/app and run:

cargo run --release --target thumbv7em-none-eabihf --bin executor

Network example (raw mqtt)

This example connects to a WiFi Network and to an MQTT5 broker. It subscribes to the vehicle/parameters topic and implements a cruise control override system - when cruise control is enabled and the user presses the button, it will disable cruise control by publishing the modified vehicle parameters back to the topic.

In the network_raw_mqtt.rs example adapt the SSID, WLAN-Passwort and the MQTT settings accordingly.

Goto threadx-app/cross/app and run:

cargo run --release --target thumbv7em-none-eabihf --bin network_raw_mqtt

Network example

This examples connects to a WiFi Network and to an MQTT5 broker and regularly publishes the current temperature as uMessage (see: Link to uProtocol).

In the network.rs example adapt the SSID, WLAN-Passwort and the MQTT settings accordingly.

Goto threadx-app/cross/app and run:

cargo run --release --target thumbv7em-none-eabihf --bin network

Shortcomings

• Only supports the MXAZ3166 board!
• No production ready error handling
• General structure needs to be improved
• Some more abstractions see embassy

embedded-nal

• Only a single socket can be used
• As for now the implementation is unsound as there are no checks to assure that buffers are big enough to hold incoming packets

Async executor

• 32 parallel async tasks are supported
• Simple executor which blocks the thread it runs on

Control structures

Control structures should be checked if they are moveable ie. can be copied via a simple memcopy. Often this is not explicitely documented within the ThreadX documentation hence we should assume that they cannot be moved. There are at least 2 obvious solutions:

• Make the control structures static and limit to a fixed number of for example mutexes
• Use the "std library" approach ie. pin box the control structure

Further ideas

Static tasks / threads

Veecle and embassy use statically allocated tasks via the type-impl-in-trait nightly feature. Maybe we should do the same to avoid dynamic allocation and the global allocator.