interrupt-mk2.md

CMIM - Cortex-M Interrupt Move

Stage 1 - Moving data to interrupts

use nrf52832_pac::Interrupt;
use something::Queue;

// Done at global scope, only specify types
cmim!(
    Interrupt::RADIO: bool,
    Interrupt::TIMER0: u128,
    Interrupt::UARTE0_UARTE: Queue::Producer,
);

fn main() {
    let (prod, cons) = Queue::new().split();

    // Sets the value described in `cmim!()`.
    // This is a "move" operation.
    // If the interrupt is currently active, an Error is returned.
    cmim_set!(
        Interrupt::UARTE0_UARTE,
        prod
    ).unwrap();

    NVIC::enable(Interrupt::UARTE0_UARTE);

    loop {
        let _ = cons.pop();
        // ..
    }
}

#[interrupt]
fn UARTE0_UARTE() {
    // Gets a mutable reference to the value described in `cmim!()`
    // This is a "borrow" operation.
    // This checks the currently active interrupt. If Interrupt::UARTE0_UARTE is not active, an error is returned
    // There is no other mutex.
    let data: &mut Producer = cmim_get!(Interrupt::UARTE0_UARTE).unwrap();
    data.push(0x00);
}

Stage 2 - Sharing data with a single interrupt

use nrf52832_pac::Interrupt;

// Done at global scope, only specify types
cmim!(
    Interrupt::RADIO: bool,
    Interrupt::TIMER0: u128,
    Interrupt::UARTE0_UARTE: bbqueue::Producer,
);

fn main() {
    // Same as above for setting, Interrupt must be disabled
    cmim_set!(
        Interrupt::RADIO,
        false
    ).unwrap();

    NVIC::enable(Interrupt::RADIO);

    loop {
        // Access the data in a critical section. Radio is disabled during the closure
        // This can only be called from non-interrupt context. If ANY interrupt is active,
        // an error is returned. This prevents higher prio interrupts messing with the data
        let data_copy = cmim_borrow!(
            Interrupt::RADIO,
            |data: &mut bool| {
                // trigger some flag
                *data = true;
            }
        ).unwrap();
    }
}

#[interrupt]
fn RADIO() {
    // Gets a mutable reference to the value described in `cmim!()`
    // This is a "borrow" operation.
    // This checks the currently active interrupt. If Interrupt::RADIO is not active, an error is returned
    // There is no other mutex.
    let data: &mut bool = cmim_get!(Interrupt::RADIO).unwrap();
    
    if *data {
        // ...
    }
}

Stage 3 - Sharing data between interrupts

I have no idea how to do this without the possibility of deadlock. Maybe specify multiple interrupts in cmim!(), and critical section all of them at once? Maybe do priority elevation like RTFM?