      1
      2
      3
      4
      5
      6
      7
      8
      9
     10
     11
     12
     13
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45
     46
     47
     48
     49
     50
     51
     52
     53
     54
     55
     56
     57
     58
     59
     60
     61
     62
     63
     64
     65
     66
     67
     68
     69
     70
     71
     72
     73
     74
     75
     76
     77
     78
     79
     80
     81
     82
     83
     84
     85
     86
     87
     88
     89
     90
     91
     92
     93
     94
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136

    //! Control register

    /// Control register
    #[derive(Clone, Copy, Debug)]
    pub struct Control {
        bits: u32,
    }

    impl Control {
        /// Returns the contents of the register as raw bits
        pub fn bits(&self) -> u32 {
            self.bits
        }

        /// Thread mode privilege level
        pub fn npriv(&self) -> Npriv {
            if self.bits & (1 << 0) == (1 << 0) {
                Npriv::Unprivileged
            } else {
                Npriv::Privileged
            }
        }

        /// Currently active stack pointer
        pub fn spsel(&self) -> Spsel {
            if self.bits & (1 << 1) == (1 << 1) {
                Spsel::Psp
            } else {
                Spsel::Msp
            }
        }

        /// Whether context floating-point is currently active
        pub fn fpca(&self) -> Fpca {
            if self.bits & (1 << 2) == (1 << 2) {
                Fpca::Active
            } else {
                Fpca::NotActive
            }
        }
    }

    /// Thread mode privilege level
    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
    pub enum Npriv {
        /// Privileged
        Privileged,
        /// Unprivileged
        Unprivileged,
    }

    impl Npriv {
        /// Is in privileged thread mode?
        pub fn is_privileged(&self) -> bool {
            *self == Npriv::Privileged
        }

        /// Is in unprivileged thread mode?
        pub fn is_unprivileged(&self) -> bool {
            *self == Npriv::Unprivileged
        }
    }

    /// Currently active stack pointer
    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
    pub enum Spsel {
        /// MSP is the current stack pointer
        Msp,
        /// PSP is the current stack pointer
        Psp,
    }

    impl Spsel {
        /// Is MSP the current stack pointer?
        pub fn is_msp(&self) -> bool {
            *self == Spsel::Msp
        }

        /// Is PSP the current stack pointer?
        pub fn is_psp(&self) -> bool {
            *self == Spsel::Psp
        }
    }

    /// Whether context floating-point is currently active
    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
    pub enum Fpca {
        /// Floating-point context active.
        Active,
        /// No floating-point context active
        NotActive,
    }

    impl Fpca {
        /// Is a floating-point context active?
        pub fn is_active(&self) -> bool {
            *self == Fpca::Active
        }

        /// Is a floating-point context not active?
        pub fn is_not_active(&self) -> bool {
            *self == Fpca::NotActive
        }
    }

    /// Reads the CPU register
    #[inline]
    pub fn read() -> Control {
        match () {
            #[cfg(cortex_m)]
            () => {
                let r = match () {
                    #[cfg(feature = "inline-asm")]
                    () => {
                        let r: u32;
                        unsafe { asm!("mrs $0, CONTROL" : "=r"(r) ::: "volatile") }
                        r
                    }

                    #[cfg(not(feature = "inline-asm"))]
                    () => unsafe {
                        extern "C" {
                            fn __control() -> u32;
                        }

                        __control()
                    },
                };

                Control { bits: r }
            }

            #[cfg(not(cortex_m))]
            () => unimplemented!(),
        }
    }

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g. `str,u8` or `String,struct:Vec,test`)