Why Rust is Better than C and C++ for Embedded Systems Programming

23 Jul, 2025

Introduction

Listen up, because I’m about to lay down some truth. C has been the king of embedded systems for decades, and yeah, it’s got its strengths—low-level control, predictable performance, and a massive ecosystem that’s been around since the dawn of computing. But let’s not kid ourselves: C is a minefield of memory bugs, and in embedded systems, where a single mistake can crash a car or brick a medical device, that’s just not good enough. Rust, on the other hand, is like Arch Linux for systems programming: it’s modern, it’s robust, and it’s built for people who want to get it right without babysitting every pointer. Rust’s memory safety, concurrency support, and killer tooling make it a superior choice for embedded systems, and I’m here to tell you why, with some real-world examples and hard data to back it up.

The Case for Rust in Embedded Systems

Embedded systems — those tiny computers in your car, smartwatch, or industrial machinery—demand reliability, efficiency, and often real-time performance. C has been the go-to because it’s fast and gives you raw control over hardware. But C’s lack of memory safety is a ticking time bomb. Buffer overflows, null pointer dereferences, and data races are the kind of bugs that keep embedded developers up at night. Rust, created by Mozilla and now backed by the Rust Foundation, flips the script by offering memory safety without sacrificing performance. It’s like having a compiler that’s smarter than your average C coder, catching errors before they become disasters.

Here’s why Rust is stealing C’s crown in embedded systems:

1. Memory Safety: No More Shooting Yourself in the Foot Rust’s ownership model is its secret sauce. It enforces strict rules about how memory is accessed, ensuring that you can’t have dangling pointers or buffer overflows. These are caught at compile time, not when your device is already in the field causing chaos. In C, you’re on your own, and even the best developers make mistakes. 60–70% of security vulnerabilities in embedded systems are memory-related. Rust eliminates these by design. For example, Android’s Bluetooth stack rewrite in Rust eradicated all memory safety bugs, and AWS reports zero memory safety issues in their Rust-based services.
2. Fearless Concurrency Modern embedded systems often juggle multiple tasks or run on multi-core processors. In C, concurrency is a nightmare—you’re stuck sprinkling locks everywhere and hoping you didn’t miss a race condition. Rust’s type system makes concurrency safe by preventing data races at compile time. This is huge for embedded systems, where tasks like sensor processing and communication need to happen simultaneously without crashing. The Embedded Rust Book highlights how Rust’s concurrency model ensures “fearless concurrency,” letting developers focus on logic rather than synchronization bugs.
3. Performance That Matches C Rust isn’t some high-level language that trades speed for safety. It’s designed with zero-cost abstractions, meaning you get high-level features without runtime overhead. Benchmarks show Rust and C have comparable CPU utilization and memory footprint when optimized properly. A 2022 study from the IEEE/ACM found Rust to be, on average, 1.77x slower than C in micro-benchmarks, but the gap varies and is often negligible in real-world applications. For embedded systems, where every cycle counts, Rust delivers the goods without compromising.
4. Modern Tooling: Cargo Kicks Makefiles to the Curb C’s build systems, like make or gcc, are clunky and error-prone. Rust’s Cargo is a breath of fresh air, handling dependencies, builds, and testing with ease. Want to add a library? Cargo’s got you covered. Need to run unit tests? It’s built-in. Rust also supports cross-compilation out of the box, making it a breeze to test on your host machine before deploying to a microcontroller. Compare that to C, where you’re wrestling with linker scripts and praying your toolchain doesn’t break.
5. Growing Ecosystem and Community Rust’s embedded ecosystem is booming. The embedded-hal crate provides a hardware abstraction layer for various microcontrollers, while tools like svd2rust generate safe bindings from hardware descriptions. The Rust community is active, with contributions from companies like Espressif, who support Rust on their ESP32 chips. Sure, C’s ecosystem is massive, but Rust’s is catching up fast, and it’s designed with modern needs in mind.

Real-World Success Stories

Rust isn’t just theoretical—it’s being used in production, and the results are impressive.

Volvo Cars: Volvo is deploying Rust in their EX90 and Polestar 3 vehicles for components like the Central Electronic Module. Julius Gustavsson, a technical expert at Volvo, praises Rust for reducing debugging time and enabling safer refactoring. Rust’s built-in testing and cross-platform support have streamlined their development process, and they’re even contributing to open-source Rust projects like CAN bus crates (Volvo Cars Engineering).

Android: The Android Open Source Project rewrote their Bluetooth stack in Rust, eliminating all memory safety bugs in that component. This is a big deal for a system where security is critical.

AWS: Amazon Web Services has adopted Rust for performance-critical services, reporting zero memory safety bugs since switching.

Microsoft: Microsoft is using Rust in their Azure Sphere IoT platform and gradually introducing it into Windows for security-critical components.

Battery Management Systems (BMS): Promwad highlights Rust’s use in electric vehicle BMS, where its zero-cost abstractions optimize battery usage and prevent bugs that could lead to inaccurate readings

Challenges and Trade-offs

Rust isn’t a magic bullet, and I’m not going to sugarcoat it. There are hurdles to adopting it in embedded systems:

1. Learning Curve: Rust’s ownership and borrowing concepts can be a shock to C developers used to raw pointers. It’s like switching from a manual typewriter to a modern IDE—powerful, but it takes time to master.
2. Ecosystem Maturity: C’s been around for 50 years, so it has libraries and vendor support for every chip under the sun. Rust’s ecosystem is younger, and while it supports popular platforms like ARM Cortex-M and ESP32, some niche hardware might lack Rust bindings.
3. Interoperability: Mixing Rust with existing C codebases requires tools like bindgen or cbindgen, which can add complexity. However, Rust’s zero-overhead C integration makes this manageable.
4. Tooling Gaps: Some Static Application Security Testing (SAST) tools struggle with Rust’s advanced features, which can complicate verification in regulated environments.

Despite these challenges, the benefits outweigh the drawbacks, especially for new projects or systems where safety is paramount. C’s “defensive programming” with MISRA rules and static analyzers can help, but Rust’s compiler enforces safety that humans can’t consistently achieve.

Performance Comparison

Let’s talk numbers. A 2022 IEEE/ACM study found Rust to be, on average, 1.77x slower than C in micro-benchmarks, but the slowdown varies by program and is often negligible in optimized code. In embedded systems, where code is carefully tuned, Rust’s performance is comparable to C’s, with similar CPU utilization and memory footprint (CPP Cat). Rust can even outperform C in some cases by enabling aggressive compiler optimizations. For example, a Hacker News thread cites benchmarks where Rust beat C, thanks to its modern idioms like slices. For bare-metal embedded development, Rust can generate “bare” code without the standard library, keeping binaries lean.

Industry Adoption and Future Outlook

Rust’s adoption is gaining steam, especially in safety-critical industries. Volvo’s success with Rust in automotive software has led to contributions to open-source projects, like a CAN bus crate. AUTOSAR, an automotive standards group with members like Ford, GM, and Toyota, has formed a subgroup to explore Rust for safety-related systems. The White House has even pushed for memory-safe languages like Rust to improve software security. While C still dominates due to its history and vendor support, Rust’s trajectory is clear: it’s becoming a first-class citizen in embedded systems.

Conclusion

Rust is the Arch Linux of embedded systems programming: it’s powerful, modern, and built for those who demand control without chaos. Its memory safety eliminates entire classes of bugs that C developers have been wrestling with for decades. Its concurrency support makes it ready for the multi-core future, and its performance matches C’s without the baggage. Sure, there’s a learning curve, and the ecosystem isn’t as vast as C’s, but the trade-offs are worth it. Companies like Volvo, Android, and Microsoft are proving Rust’s worth in production, delivering safer, more reliable embedded systems. If you’re starting a new embedded project or working on something where a bug could be catastrophic, Rust is the way to go. C’s had a good run, but it’s time to move on to something that doesn’t make you debug segfaults at 3 a.m.