demo.rs

//! A basic loop-back task on port 100
//!
//! Using https://github.com/tosc-rs/mnemos/pull/25

// Holds the types and uuid constant
use drivers::SerialPorts;
 
// Get the serial port mux interface, taking a read
// lock on the registry. We don't know the kind or
// implementor of the SerialPorts driver, just its'
// messaging interface. Like "traits via message passing".
//
// Returns Ok if there is a runtime-registered serial
// port driver available.
let ports = SerialPorts::new(
    &kernel.registry().await,
).await?;
 
// Open up port 0, gives us back a bidirectional
// bbq stream interface. Under the hood, this sends
// a message to the driver, and waits for the response.
let port_0 = ports.open(100).await?;
 
// Spawn a "loopback port" task
kernel.spawn(async move {
    // We communicate with the driver regarding the port
    // exclusively through the stream interface.
    loop {
        let mut rgr = port_0.reader().read_grant().await;
        let len = rgr.len();
 
        port_0.send(&rgr).await;
        rgr.release(len);
    }
}).await;