64 lines
1.8 KiB
Rust
64 lines
1.8 KiB
Rust
//! Minimal Cortex-M program
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//!
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//! When executed this program will hit the breakpoint set in `main`.
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//!
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//! All Cortex-M programs need to:
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//!
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//! - Contain the `#![no_main]` and `#![no_std]` attributes. Embedded programs don't use the
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//! standard Rust `main` interface or the Rust standard (`std`) library.
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//!
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//! - Define their entry point using [`entry!`] macro.
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//!
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//! [`entry!`]: https://docs.rs/cortex-m-rt/~0.5/cortex_m_rt/macro.entry.html
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//!
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//! - Define their panicking behavior, i.e. what happens when `panic!` is called. The easiest way to
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//! define a panicking behavior is to link to a [panic handler crate][0]
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//!
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//! [0]: https://crates.io/keywords/panic-impl
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//!
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//! - Define the `HardFault` handler using the [`exception!`] macro. This handler (function) is
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//! called when a hard fault exception is raised by the hardware.
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//!
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//! [`exception!`]: https://docs.rs/cortex-m-rt/~0.5/cortex_m_rt/macro..html
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//!
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//! - Define a default handler using the [`exception!`] macro. This function will be used to handle
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//! all interrupts and exceptions which have not been assigned a specific handler.
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#![no_main] // <- IMPORTANT!
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#![no_std]
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extern crate cortex_m;
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#[macro_use(entry, exception)]
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extern crate cortex_m_rt as rt;
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// makes `panic!` print messages to the host stderr using semihosting
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extern crate panic_semihosting;
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use cortex_m::asm;
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use rt::ExceptionFrame;
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// the program entry point is ...
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entry!(main);
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// ... this never ending function
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fn main() -> ! {
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loop {
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asm::bkpt();
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}
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}
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// define the hard fault handler
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exception!(HardFault, hard_fault);
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fn hard_fault(ef: &ExceptionFrame) -> ! {
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panic!("HardFault at {:#?}", ef);
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}
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// define the default exception handler
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exception!(*, default_handler);
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fn default_handler(irqn: i16) {
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panic!("Unhandled exception (IRQn = {})", irqn);
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}
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