Rust: The Embedded Language That’s Outperforming C

C and C++ have been the only programming languages that are used to program embedded systems for at least the past 50 years. But this is about to change.

Rust: A Brief Introduction
Rust is a modern, statically typed programming language that combines the performance of C/C++ with memory safety and expressive syntax. It was designed by Mozilla to address the shortcomings of C and C++ while providing a safer and more ergonomic alternative. Here’s why Rust is such a big deal for embedded systems:

1. Memory Safety
   C, despite its widespread use in embedded systems, is notorious for memory-related bugs like buffer overflows, null pointer dereferences, and data races. These issues can lead to system crashes, security vulnerabilities, and even life-threatening situations (think medical devices or automotive control systems). Rust, on the other hand, guarantees memory safety at compile time through its ownership and borrowing system. This means no more dangling pointers or buffer overflows.
2. Zero-Cost Abstractions
   Rust allows developers to write high-level code without sacrificing performance. Its zero-cost abstractions enable expressive constructs like iterators, closures, and pattern matching, all while compiling down to efficient machine code. This is a game-changer for embedded systems, where performance is critical.
3. Fearless Concurrency
   Embedded systems in the present day often require concurrent execution (e.g., handling sensor inputs, communication protocols, and real-time tasks). Rust’s ownership model ensures thread safety without the need for locks or mutexes. The borrow checker prevents data races, making it easier to reason about concurrent code.
4. No Undefined Behavior
   C’s undefined behavior is a notorious pitfall. Rust eliminates this by design. If your Rust code compiles, you’re guaranteed not to encounter undefined behavior at runtime. Just imagine how transformational this predictability is for safety-critical systems.
5. Ecosystem and Libraries
   Rust’s ecosystem is rapidly growing. Crates (Rust’s package manager) provide reusable components, and libraries like embedded-hal abstract hardware interfaces. Tools like svd2rust generate peripheral access APIs directly from vendor provided SVD files. Additionally, the rtic framework simplifies real-time programming.
6. Interoperability
   Rust can seamlessly interface with C code. You can call C functions from Rust and vice versa. This makes it easier to adopt Rust incrementally, leveraging existing C libraries in the applications.

Challenges and Considerations
While Rust offers significant advantages, it’s not perfect (yet):

1. Learning Curve: Rust’s ownership model can be daunting initially. Developers accustomed to C may need time to adapt.
2. Ecosystem Maturity: Although Rust’s ecosystem is growing, it’s not as mature as C’s. Some chips lack Rust support, and existing libraries may be limited.
3. Tooling: While tools like cargo (Rust’s build system) are excellent, they differ from the familiar make or gcc. Learning new workflows takes time and Rust developers are still rare.
4. Community Adoption: Rust’s adoption in embedded systems is increasing, but it’s not universal. Some developers still prefer C due to familiarity.

Conclusion

Rust’s blend of safety, performance, and expressive power positions it as a compelling choice for embedded software development. While it won’t replace C overnight, its trajectory is promising. As more developers embrace Rust, we’ll witness a safer, more efficient era in embedded systems programming.
A very important point before you drop your C textbooks and start learning Rust, is context. Rust is particularly a game changer for modern embedded applications with RTOS where safety and concurrency matters. It will not replace the legacy resource-constrained systems designed on C to do the bare-minimum embedded stuff (yes, Rust is not coming to 8086).
Whenever a new branch of technology pops out, the greatest number of opportunities are created for the freshers due to their naturally high learning speed and lack of prejudices of legacy technologies (yes, that’s the dark side of industry experience) as they do not have a friction to switch technologies. This could be the next big thing, and you have the power to cease it!