How to Write a Device Driver in Rust

Writing a device driver in Rust requires using the #![no_std] attribute to disable the standard library and implementing hardware-specific traits from crates like embedded-hal or embedded-drivers. You must manage memory manually and interact with hardware registers using volatile reads and writes, often via the vcell or portable-atomic crates. Start by creating a binary crate with #![no_std] and defining your hardware interface using unsafe blocks where necessary.

#![no_std]
#![no_main]

use core::panic::PanicInfo;

#[panic_handler]
fn panic(_info: &PanicInfo) -> ! {
    loop {}
}

#[no_mangle]
pub extern "C" fn _start() -> ! {
    // Initialize hardware here
    loop {}
}

You will also need a linker script to define memory layout and a boot loader to jump to your _start function.

Writing a device driver in Rust means building low-level software that talks directly to hardware without relying on an operating system. You have to handle memory and hardware controls yourself, similar to writing a custom instruction manual for a specific machine. This approach is used when you need maximum performance and safety for embedded devices like microcontrollers or operating system kernels.