cortex-m 0.4.3

Low level access to Cortex-M processors
Documentation
//! Priority mask register

/// All exceptions with configurable priority are ...
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum Primask {
    /// Active
    Active,
    /// Inactive
    Inactive,
}

impl Primask {
    /// All exceptions with configurable priority are active
    pub fn is_active(&self) -> bool {
        *self == Primask::Active
    }

    /// All exceptions with configurable priority are inactive
    pub fn is_inactive(&self) -> bool {
        *self == Primask::Inactive
    }
}

/// Reads the CPU register
#[inline]
pub fn read() -> Primask {
    match () {
        #[cfg(target_arch = "arm")]
        () => {
            let r: u32;
            unsafe { asm!("mrs $0, PRIMASK" : "=r"(r) ::: "volatile") }
            if r & (1 << 0) == (1 << 0) {
                Primask::Inactive
            } else {
                Primask::Active
            }
        }
        #[cfg(not(target_arch = "arm"))]
        () => unimplemented!(),
    }
}