Module cortex_m_quickstart::examples::_4_override_exception_handler

Overriding an exception handler

You can override an exception handler using the exception! macro.

The default exception handler can be overridden using the default_handler! macro

---

#![feature(used)]
#![no_std]
 
extern crate cortex_m;
#[macro_use(exception)]
extern crate cortex_m_rt;
 
use core::ptr;
 
use cortex_m::asm;
 
fn main() {
    unsafe {
        // Invalid memory access
        ptr::read_volatile(0x2FFF_FFFF as *const u32);
    }
}
 
exception!(HARD_FAULT, handler);
 
fn handler() {
    // You'll hit this breakpoint rather than the one in cortex-m-rt
    asm::bkpt()
}
 
// As we are not using interrupts, we just register a dummy catch all handler
#[allow(dead_code)]
#[used]
#[link_section = ".vector_table.interrupts"]
static INTERRUPTS: [extern "C" fn(); 240] = [default_handler; 240];
 
extern "C" fn default_handler() {
    asm::bkpt();
}