pub fn bound_handler(interrupt: Interrupt) -> Option<unsafe extern "C" fn()> {
        unsafe {
            let addr = pac::__EXTERNAL_INTERRUPTS[interrupt as usize]._handler;
            if addr as usize == 0 {
                return None;
            }

            Some(addr)
        }
    }
Returns the currently bound interrupt handler.
esp-hal/src/interrupt/riscv.rs