bare0.rs

//! bare0.rs
//! Simple bare metal application

// feature to ensure symbols to be linked
#![feature(used)]
// build without the Rust standard library
#![no_std]

// Minimal runtime / startup for Cortex-M microcontrollers
extern crate cortex_m_rt;

const X_INIT: u32 = 10;

static mut X: u32 = X_INIT;
static mut Y: u32 = 0;

#[inline(never)]
fn main() {
    let mut x = unsafe { X };

    loop {
        x += 1;
        unsafe {
            X += 1;
            Y = X;
            assert!(x == X && X == Y);
        }
    }
}

// As we are not using interrupts, we just register a dummy catch all handler
#[link_section = ".vector_table.interrupts"]
#[used]
static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];

extern "C" fn default_handler() {
    loop {}
}