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name: domain-embedded description: "Use when developing embedded/no_std Rust. Keywords: embedded, no_std, microcontroller, MCU, ARM, RISC-V, bare metal, firmware, HAL, PAC, RTIC, embassy, interrupt, DMA, peripheral, GPIO, SPI, I2C, UART, embedded-hal, cortex-m, esp32, stm32, nrf, 嵌入式, 单片机, 固件, 裸机" globs: ["/Cargo.toml", "/.cargo/config.toml"]

Embedded Domain

Layer 3: Domain Constraints

Domain Constraints → Design Implications

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Critical Constraints

No Dynamic Allocation

CopyRULE: Cannot use heap (no allocator)
WHY: Deterministic memory, no OOM
RUST: heapless::Vec<T, N>, arrays

Interrupt Safety

CopyRULE: Shared state must be interrupt-safe
WHY: ISR can preempt at any time
RUST: Mutex<RefCell<T>> + critical section

Hardware Ownership

CopyRULE: Peripherals must have clear ownership
WHY: Prevent conflicting access
RUST: HAL takes ownership, singletons

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Trace Down ↓

From constraints to design (Layer 2):

Copy"Need no_std compatible data structures"
    ↓ m02-resource: heapless collections
    ↓ Static sizing: heapless::Vec<T, N>

"Need interrupt-safe state"
    ↓ m03-mutability: Mutex<RefCell<Option<T>>>
    ↓ m07-concurrency: Critical sections

"Need peripheral ownership"
    ↓ m01-ownership: Singleton pattern
    ↓ m12-lifecycle: RAII for hardware

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Layer Stack

Framework Comparison

Key Crates

Design Patterns

Code Pattern: Static Peripheral

Copy#![no_std]
#![no_main]

use cortex_m::interrupt::{self, Mutex};
use core::cell::RefCell;

static LED: Mutex<RefCell<Option<Led>>> = Mutex::new(RefCell::new(None));

#[entry]
fn main() -> ! {
    let dp = pac::Peripherals::take().unwrap();
    let led = Led::new(dp.GPIOA);

    interrupt::free(|cs| {
        LED.borrow(cs).replace(Some(led));
    });

    loop {
        interrupt::free(|cs| {
            if let Some(led) = LED.borrow(cs).borrow_mut().as_mut() {
                led.toggle();
            }
        });
    }
}

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Common Mistakes

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Trace to Layer 1

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Related Skills