rticx-cortex-m 0.2.1

RTICX distribution for single-core Cortex-M targets (armv6-m and armv7-m and above)
Documentation

Single-core Cortex-M RTICX distribution

This distribution targets single-core Cortex-M microcontrollers, mirroring the upstream RTIC cortex-m backend. It supports two mutually-exclusive locking strategies selected at crate-feature time:

Feature Architecture Locking mechanism
(default) armv7-m and above BASEPRI register (priority threshold)
armv6m armv6-m (M0/M0+/M23) Interrupt source masking via NVIC ISER/ICER
async all Async/Await software tasks
swtasks all Simple software tasks

Layout

rticx-cortex-m/
├── src/                 # `rtic` library: re-exports `app` macro and runtime exports
├── rtic-macro/           # proc-macro crate implementing CorePassBackend + SwPassBackend
├── qemu-run.sh           # build + boot an example under QEMU
└── examples-apps/        # one crate for both archs: thumbv7m (BASEPRI) and
                          # thumbv6m (source masking), selected by `--target`

Documentation

Full user guide is available in the project wiki.

The QEMU playground

The hello_rtic example is a simple RTICX application that runs under QEMU and exercises the core primitives provided by this distribution:

  1. #[init] configures the SysTick timer (SYST) to fire periodically.
  2. Hardware task bound to an exception: Tick is bound to the SysTick exception handler. On each tick it spawns the software task.
  3. Software task on an NVIC dispatcher Worker runs off the TIM6 NVIC interrupt, acquires the shared counter through a resource lock, increments it, and once it reaches TARGET calls debug::exit(EXIT_SUCCESS).

Prerequisites

# QEMU (Linux/Debian; macOS: `brew install qemu`)
sudo apt-get install -y qemu-system-arm

# Rust targets (CI runs `rustup target add` automatically)
rustup target add thumbv7m-none-eabi thumbv6m-none-eabi

Running the examples

make qemu-armv7m
make qemu-armv6m

Or, per-example (the .cargo/config.toml wires up the QEMU runner, so cargo run both builds and boots QEMU):

# thumbv7m (BASEPRI locking), default target
cd examples-apps && cargo run --example hello_rtic
cd examples-apps && cargo run --example async_ping_pong --features "async"

# thumbv6m (interrupt source masking): the target triple alone selects the
# `armv6m` lock path, no cargo feature flag needed
cd examples-apps && cargo run --target thumbv6m-none-eabi --example hello_rtic