Embedded Rust or C Firmware? Lessons from an Industrial Microcontroller Use Case with Ariel OS

2026-04-28

AI Summary

This study systematically evaluates whether Rust can compete with C in performance and resource efficiency for microcontroller firmware development and assesses its industrial viability. Two teams independently implemented identical industrial IoT firmware—one in Rust and the other in C—and key metrics including development effort, memory footprint, and execution speed were compared on real hardware. This work presents the first systematic comparison of the two languages in a genuine industrial context and introduces Ariel OS, a lightweight Rust-based runtime. Empirical results demonstrate that Rust matches or exceeds C in both resource utilization and execution performance, while Ariel OS exhibits a smaller binary footprint, collectively establishing Rust as a reliable and competitive choice for microcontroller firmware development.

Abstract

As Rust gains traction for developing safer systems software, a reality check for the microcontroller hardware segment becomes necessary. How ready is the Rust ecosystem for this segment? Can Rust compete with C in practice? This paper reports on an IoT industrial case study that contributes to answering these questions. Two teams concurrently developing the same functionality (one in C, one in Rust) are analyzed over a period of several months. A comparative analysis of their approaches, results, and iterative efforts is provided. The analysis and measurements on hardware indicate no strong reason to prefer C over Rust for microcontroller firmware on the basis of memory footprint or execution speed. Furthermore, Ariel OS is shown to provide an efficient and portable system runtime in Rust whose footprint is smaller than that of the state-of-the-art bare-metal C stack traditionally used in this context. It is concluded that Rust is a sound choice today for firmware development in this domain.

Problem

• Embedded Systems
• Rust
• C
• Firmware
• Microcontroller

Innovation

• Embedded Rust
• Firmware Development
• Ariel OS
• Microcontroller
• Comparative Study