How to Handle Interrupts in Embedded Rust

Handle interrupts in embedded Rust by defining functions with target-specific extern ABIs like "avr-interrupt" or "riscv-interrupt-m" and marking them with #[no_mangle].

Handle interrupts in embedded Rust by defining a function with the target-specific extern ABI (e.g., "avr-interrupt", "riscv-interrupt-m", or "x86-interrupt") and marking it with #[no_mangle] to ensure the linker recognizes the symbol. These functions must be unsafe and typically return ! (never) to indicate they do not return to the caller in the standard sense.

#[no_mangle]
unsafe extern "avr-interrupt" fn timer_overflow_handler() {
    // Critical interrupt logic here
    // Do not return; the hardware handles the return
}

Interrupts are signals from hardware that pause your program to handle urgent events like a timer or sensor input. You handle them by writing a special function that the hardware automatically jumps to when the event occurs. Think of it like a phone ringing; your code pauses what it is doing to answer the call, then immediately goes back to its previous task.