mmio

Abstractions for performing memory-mapped I/O.

Code of Conduct

See the Rust Code of Conduct.

Contribution

See CONTRIBUTING.md.

Changelog

See CHANGELOG.md.

License

See LICENSE.md.

lib.rs:

Abstractions for performing memory-mapped I/O.

Memory-mapped I/O (MMIO) requires working with raw pointers and volatile memory accesses, both of which require manually reasoning about safety. This crate provides the VolBox (pronounced "volatile box") smart pointer, which expresses unique ownership of a volatile memory location. Additionally, it follows the "unsafe initialization, safe use" pattern to offload safety reasoning to the borrow checker after VolBox::new.

Importantly, this crate is careful to never create references to volatile memory locations.

Examples

let mut thr = unsafe {
    VolBox::<u8, Allow, Allow>::new(0x1000_0000 as *mut u8)
};
let lsr = unsafe {
    VolBox::<u8, Allow, Allow>::new(0x1000_0005 as *mut u8)
};
loop {
    if lsr.read() & 0x20 != 0x0 {
        break;
    }
}
thr.write(b'\n');