Jens Siebert gave a presentation on using Rust for embedded systems. He discussed the history and characteristics of Rust, how it provides memory safety and concurrency without overhead. He also covered Rust's support for embedded targets through crates like embedded-hal and board-specific crates. As an example, he showed how to set up a project to blink an LED on the Raspberry Pi Pico using Rust and its embedded ecosystem. He concluded that Rust is well-suited for embedded due to its performance, safety features, architecture support, and available drivers, though it has a steep learning curve.

1. Jens Siebert, IoT Hessen Meetup (Kassel), 23.11.2023
Embedded Rust

2. About me
• Senior Software Architect @ CARIAD
• Safety-critical Automotive Software for Pulse Inverters
• Maker, 3D Printing, (Programming Language) Nerd

3. Hello… IoT Hessen Meetup!

4. About Rust
• Started in 2006 as a private project of Graydon Hoare.
• Supported and adopted by Mozilla from 2009.
• Released as 1.0 on May 15th 2015.
• Rust Foundation established in 2021.
• Sponsors and Users: Amazon (AWS), Microsoft, Google, Mozilla, Meta, etc.
• „Most loved programming language“ in Stack Over
fl
ow Developer Survey since 2016.
• Stable release every 6 weeks, a new „edition“ (roughly) every 3 years.

5. Characteristics of Rust
• Multi-paradigm system-level programming language
(high-level ergonomics, low-level control).
• Compiled to binary code (no interpreter, JIT compiler, etc.).
• Automatic memory management without a garbage collector
(“Fearless Memory Management“).
• Concurrency without data races (“Fearless Concurrency“).
• Abstractions with minimal overhead (“Zero Cost Abstractions“).
• E
ffi
cient interfacing to C/C++.
• Expressive and helpful error messages of the compiler.

6. Ownership

7. Borrowing

8. Mutable References

9. Structs & Traits

10. Structs & Traits

11. Enumerations & Pattern Matching

12. Enumerations & Pattern Matching

13. Error Handling (panic!, Result Datatype)

14. Concurrency

15. Unsafe Code

16. Crates
cargo add rp-pico

17. Tools, Tools, Tools…
• rustup — Management of the Rust Installation.
• rustc — The Rust Compiler.
• cargo — Project/Build/Test/Documentation/Package Management
• Knurling Tools
• probe-run — cargo runner for
fl
ashing and execution of embedded applications (e.g. using JTAG)
• defmt — Logging Framework
• flip-link — Stack Protection
• app-template — Project templates for embedded applications
• defmt-test — Framework for on-device tests

18. rustc — Target Platform Support Policy
• Tier 1: Continuous Integration checks that tier 1 targets will always build and
pass tests.
• Tier 2: Continuous Integration checks that tier 2 targets will always build, but
they may or may not pass tests.
• Tier 3: No guarantees about tier 3 targets; they exist in the codebase, but
may or may not build.
https://doc.rust-lang.org/rustc/target-tier-policy.html

19. Target Platform Support — Tier 1*
Target
aarch64-unknown-linux-gnu
i686-pc-windows-gnu
i686-pc-windows-msvc
i686-unknown-linux-gnu
x86_64-apple-darwin
x86_64-pc-windows-gnu
x86_64-pc-windows-msvc
x86_64-unknown-linux-gnu
https://doc.rust-lang.org/rustc/platform-support.html#tier-1-with-host-tools
* => Tier 1 with Host Tools

20. Target Platform Support — Tier 2
Target std
aarch64-unknown-none-soft
fl
oat *
aarch64-unknown-none *
armebv7r-none-eabi *
armebv7r-none-eabihf *
armv7a-none-eabi *
armv7r-none-eabi *
armv7r-none-eabihf *
riscv32i-unknown-none-elf *
riscv32imac-unknown-none-elf *
riscv32imc-unknown-none-elf *
riscv64gc-unknown-none-elf *
riscv64imac-unknown-none-elf *
thumbv6m-none-eabi *
thumbv7em-none-eabi *
thumbv7em-none-eabihf *
thumbv7m-none-eabi *
thumbv8m.base-none-eabi *
…
https://doc.rust-lang.org/rustc/platform-support.html#tier-2
* => indicates the target only supports no_std development

21. std vs. no_std
Feature no_std std
Heap (dynamic memory) * ✓
Collections (Vec, HashMap, etc.) ** ✓
Stack over
fl
ow protection ✗ ✓
Runs init code before main ✗ ✓
libstd available ✗ ✓
libcore available ✓ ✓
Writing
fi
rmware, kernel or bootloader code ✓ ✗
https://docs.rust-embedded.org/book/intro/no-std.html
** => Only if you use the collections crate and con
fi
gure a global default allocator
* => Only if you use the alloc crate and use a suitable allocator like alloc-cortex-m

22. Embedded Crates
Application
Board Support Crate Drivers
Drivers
embedded-hal Crate
embedded-hal impl Crate
Peripheral Access Crate
Microcontroller
Architecture
Support
Crate

23. Embedded Crates (Raspberry Pi Pico)
Application
Board Support Crate (rp-pico) Drivers
Drivers
embedded-hal Crate
embedded-hal impl Crate (rp-2040-hal)
Peripheral Access Crate (rp-2040-pac)
Microcontroller (Cortex-M0+)
Architecture
Support
Crate
(cortex-m)

24. Embedded HAL
I2C
embedded-hal
SPI GPIO
Serial
Timer
Watchdog PWM ADC

25. Example (Blinky on Raspberry Pi Pico, Setup)
rustup target add thumbv6m-none-eabi
cargo install elf2uf2-rs
cargo new embedded-rust

26. Project Layout
Build Tool Con
fi
guration (Target, Runner, etc.)
Source Code
Project Con
fi
guration and Dependencies

27. .cargo/config for Raspberry Pi Pico

28. Cargo.toml for Raspberry Pi Pico

29. Minimal main.rs for Raspberry Pi Pico

30. Blinky Project (Imports, main.rs)

31. Blinky Project (Initialization, main.rs)

32. Blinky Project (Pin Config and blink, main.rs)

33. Blinky Project (Result)

34. Conclusion
Rust as a language for embedded systems:
• High performance, low memory consumption.
• Safe memory management.
• Safe concurrency.
• Many supported architectures (ARM, RISC-V, etc.), controllers and boards.
• Lots of drivers for external hardware available already.
• Steep learning curve (to some extend, but it's worth it!)
• Friendly, helpful and welcoming community.
• It’s open source! (please support!!!)

35. Thank you!
www.rust-lang.org/learn
docs.rust-embedded.org/discovery/
docs.rust-embedded.org/book/
github.com/rust-embedded/awesome-embedded-rust
knurling.ferrous-systems.com/tools/
Github: github.com/jens-siebert
SlideShare: slideshare.net/JensSiebert1
LinkedIn: www.linkedin.com/in/jenssiebert/
Mastodon: mastodon.online/@jens_siebert