A Paradigm Shift in Embedded Systems

For decades, C has dominated embedded programming. Now, Rust is emerging as a powerful alternative, promising a future of safer, more reliable systems by fundamentally rethinking memory safety.

Embedded Market Share (2024)

The Memory Safety Crisis

~70%

of critical security vulnerabilities at major tech companies are caused by memory safety bugs—the very class of errors Rust is designed to prevent at compile time.

The Challenge with C: Manual Memory Management

C grants programmers immense power and control, but this comes with the full responsibility of managing memory manually. Small oversights can lead to severe vulnerabilities that are difficult to detect.

Buffer Overflow

When more data is written to a buffer than it can hold, it spills into adjacent memory, corrupting data or enabling exploits.

buffer[1]
Adjacent Memory

Rust's Solution: Compile-Time Guarantees

Rust enforces a set of rules at compile time that guarantee memory safety without a garbage collector. This is achieved through its innovative Ownership, Borrowing, and Lifetimes system.

The Ownership Model in Action

1

Single Owner

Each value has one—and only one—owner. Here, `s1` owns the heap data.

let s1 = String::from("Hello, Rust!");
2

Ownership Moves

When assigned, ownership is moved. `s1` is now invalid, preventing use-after-free.

let s2 = s1;
3

Compiler Error

Attempting to use `s1` after the move results in a compile-time error, not a runtime crash.

println!("{}", s1); // This line won't compile!

The Borrow Checker Rules

Multiple immutable borrows (`&`) are allowed.

Many parts of the code can read the data at once, safely.

Only one mutable borrow (`&mut`) is allowed.

Ensures exclusive write access, preventing data races and unexpected changes.

Putting It Into Practice

While Rust's safety is a clear advantage, how does it stack up in practical terms like performance and binary size?

Binary Size: "Blinky" App Comparison

While Rust's default binary can be larger, aggressive optimization brings it into a competitive range for resource-constrained devices.

A Rapidly Maturing Ecosystem

Rust's power is amplified by a modern, integrated toolchain and a vibrant community building foundational libraries and frameworks.

Cargo

An integrated package manager and build system that simplifies dependency management and project setup.

`probe-rs`

A modern toolkit for debugging and flashing embedded devices, supporting ARM and RISC-V targets.

`embedded-hal`

A set of traits providing a portable Hardware Abstraction Layer for writing reusable drivers.

`svd2rust`

Auto-generates safe, type-rich Rust APIs for peripherals from vendor-provided SVD files.

RTIC Framework

A lightweight concurrency framework for real-time systems that guarantees thread and memory safety at compile time.

Embassy Framework

A modern `async` framework that makes it easy to write efficient, non-blocking concurrent applications.

References

  1. TrustInSoft. "Rust's Hidden Dangers: Unsafe, Embedded, and FFI Risks."
  2. CPP Cat. "Rust vs C++ for Embedded Systems: A Comprehensive Comparison."
  3. Snyk Learn. "Null Dereference."
  4. Embedded.com. "Memory Safety in Rust."
  5. Rust Programming Language. "Embedded devices."
  6. NCC Group. "Rust for Security and Correctness in the embedded world."
  7. Nirma University. "Rust: The Embedded Language That's Outperforming C."
  8. The Embedded Rust Book. "Concurrency."
  9. Amity University. "Can Rust finally replace C?: A qualitative and quantitative analysis."
  10. MoldStud. "Advanced Rust Programming Patterns for Embedded Systems."
  11. RunSafe Security. "Converting C++ to Rust: RunSafe's Journey to Memory Safety."
  12. Dev.to. "Ownership in Rust."
  13. Jackson State University. "Buffer Overflow Attacks."
  14. The Rust Programming Language. "What Is Ownership?"
  15. Krishnag. "Understanding CWE-476: Null Pointer Dereference."
  16. Nora Codes. "What Is Rust's unsafe?"
  17. The Embedded Rust Book. "The Borrow Checker."
  18. Stack Overflow. "What exactly is meant by de-referencing a null pointer?"
  19. Kobzol's Blog. "Making Rust binaries smaller by default."
  20. Embedded.com. "Embedded Rust: where are we today?"
  21. Rust Embedded · GitHub.
  22. Docs.rs. "embedded_registers."
  23. CQR Company. "Use-After-Free Vulnerability."
  24. Stack Overflow. "Could software written only in Rust fully avoid race conditions?"
  25. Rust Project Primer. "Minimizing Rust Binary Size."
  26. Reddit. "The mystery of the Rust embedded binary size."
  27. Phil-Opp's Blog. "Async/Await in a bare-metal Rust operating system."
  28. GitHub. "buffer-overflow-attack/stack.c."
  29. Awesome Rust. "IDE Support."
  30. OpenTitan Documentation. "Rust for Embedded C Programmers."
  31. Reddit. "Unsafe Rust everywhere? Really?"
  32. Reddit. "Should I start learning embedded in Rust instead of C?"
  33. ROS Discourse. "Embedded Development in Rust."
  34. Stack Overflow. "Rust how to start an embedded project."
  35. Stack Overflow. "Rust vs C/C++: Is Rust better than C/C++ or is a skill issue?"