# rust-embedded/cortex-m

Low level access to Cortex-M processors

Repository: https://github.com/rust-embedded/cortex-m
Canonical: https://ross.abutalabs.com/products/cortex-m
Language: Rust
License: Apache-2.0
License Family: permissive
Topics: rust, no-std, arm, cortex-m, microcontroller
Last push: 2026-09-02T20:54:06+00:00

## Health v2 (maintenance only)
Score: 100/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 100, longevity 100
- inputs: {"age_days": 3627, "days_push": 0, "days_rel": 0, "gap_med": 17.5, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1003, forks 201 (observed 2026-09-03T02:15:17.561655+00:00)

## What it is
A collection of Rust crates providing low-level access to ARM Cortex-M microcontroller peripherals, including CPU register access, startup code, interrupt handling, and semihosting debugging support. It is maintained by the Rust Embedded Working Group's Arm team and designed for no_std embedded development.

## Use cases
- access Cortex-M CPU registers and peripherals from Rust
- write no_std firmware for ARM Cortex-M microcontrollers
- set up startup code and interrupt handlers for embedded Rust
- debug embedded Rust programs via semihosting
- build a panic handler that outputs over ITM/SWO
- interface with peripheral access crates on Cortex-M chips

## When to choose
- you are writing Rust firmware targeting ARM Cortex-M (M0-M33) microcontrollers
- you need safe, idiomatic low-level register and peripheral access in a no_std environment
- you want community-maintained startup and interrupt handling code instead of writing it yourself

## When to avoid
- you target non-Cortex-M architectures like RISC-V, AVR, or Cortex-A
- you are writing hosted (std) Rust applications rather than embedded firmware
- you need a full hardware abstraction layer for a specific chip family - use a dedicated HAL crate instead

## Facets
- artifact type: library
- maturity: stable
- function: embedded, developer-tools
- domain: embedded-systems, developer-tools
- platform: embedded, rust
- tags: cortex-m, arm, no-std, microcontroller, rust-embedded, peripheral-access, interrupt-handling, semihosting

## Member repositories
- rust-embedded/cortex-m (main) score 100

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:17.561655+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:14:02.044900+00:00, confidence not recorded.
  - readme: https://github.com/rust-embedded/cortex-m (fetched 2026-09-03T02:15:17.561655+00:00, sha 1fea33c59b40)
  - registry_crates: https://crates.io/api/v1/crates/cortex-m (fetched 2026-08-29T13:13:53.515192+00:00, sha fb3b2578260c)
- Data as of 2026-08-30T08:39:29.467469+00:00.