Rust allows developers to enforce architectural rules at compile time rather than relying on developer discipline. By using the no_std attribute, developers can write code for microcontrollers without an operating system or dynamic memory allocation, producing machine code comparable to C and C++.
The language uses ownership models to manage hardware resources. For example, when a DMA controller starts a transfer, the buffer is moved to the DMA, preventing the main code from accessing it until the operation completes. Similarly, peripheral blocks like timers or ADCs can be assigned to specific owners, preventing conflicting access.
Rust can encode hardware states into types. A GPIO pin configured as an output can be represented by a distinct type, ensuring that functions like set_high can only be called on pins in the correct state. This shifts information from comments and runtime checks into the type system.
For concurrency, Rust requires explicit synchronization mechanisms for shared access between the main code and interrupt handlers. While unsafe blocks allow direct register manipulation, they are intended to be isolated within drivers, keeping the rest of the application verifiable by the compiler.
These abstractions do not necessarily incur runtime overhead. Many type-level checks are resolved during compilation, resulting in machine code that performs direct register writes. The language does not automatically prevent logical errors like incorrect PWM frequencies or regulator coefficients, which remain the developer's responsibility.
Adopting Rust for embedded systems requires navigating a smaller ecosystem compared to C, which often provides extensive vendor-supplied libraries and documentation. The benefits of Rust's strict ownership model become more apparent as system complexity, such as the number of timers, interrupts, and modules, increases.
