The cortex_m_rt crate provides (among other things) a reset handler for Cortex M microcontrollers.


extern crate panic_halt as _;

mod interrupts;

use cortex_m_rt::entry;

fn main() -> ! {
    loop {}

Next we’ll look at how to access peripherals, with increasing levels of abstraction.

  • The cortex_m_rt::entry macro requires that the function have type fn() -> !, because returning to the reset handler doesn’t make sense.
  • Run the example with cargo embed --bin minimal