diff options
Diffstat (limited to 'src/lib.rs')
| -rw-r--r-- | src/lib.rs | 382 |
1 files changed, 89 insertions, 293 deletions
@@ -1,22 +1,23 @@ -//! Real Time For the Masses (RTFM) framework for ARM Cortex-M microcontrollers +//! Real-Time Interrupt-driven Concurrency (RTIC) framework for ARM Cortex-M microcontrollers //! -//! **IMPORTANT**: This crate is published as [`cortex-m-rtfm`] on crates.io but the name of the -//! library is `rtfm`. +//! **HEADS UP** This is an **beta** pre-release; there may be breaking changes in the API and +//! semantics before a proper release is made. //! -//! [`cortex-m-rtfm`]: https://crates.io/crates/cortex-m-rtfm +//! **IMPORTANT**: This crate is published as [`cortex-m-rtic`] on crates.io but the name of the +//! library is `rtic`. //! -//! The user level documentation can be found [here]. +//! [`cortex-m-rtic`]: https://crates.io/crates/cortex-m-rtic //! -//! [here]: https://japaric.github.io/cortex-m-rtfm/book/en/ +//! The user level documentation can be found [here]. //! -//! Don't forget to check the documentation of the [`#[app]`] attribute, which is the main component -//! of the framework. +//! [here]: https://rtic.rs //! -//! [`#[app]`]: ../cortex_m_rtfm_macros/attr.app.html +//! Don't forget to check the documentation of the `#[app]` attribute (listed under the reexports +//! section), which is the main component of the framework. //! //! # Minimum Supported Rust Version (MSRV) //! -//! This crate is guaranteed to compile on stable Rust 1.31 (2018 edition) and up. It *might* +//! This crate is guaranteed to compile on stable Rust 1.36 (2018 edition) and up. It *might* //! compile on older versions but that may change in any new patch release. //! //! # Semantic Versioning @@ -27,73 +28,43 @@ //! release. //! //! [SemVer]: https://semver.org/spec/v2.0.0.html -//! -//! # Cargo features -//! -//! - `timer-queue`. This opt-in feature enables the `schedule` API which can be used to schedule -//! tasks to run in the future. Also see [`Instant`] and [`Duration`]. -//! -//! [`Instant`]: struct.Instant.html -//! [`Duration`]: struct.Duration.html -//! -//! - `nightly`. Enabling this opt-in feature makes RTFM internally use the unstable -//! `core::mem::MaybeUninit` API and unstable `const_fn` language feature to reduce static memory -//! usage, runtime overhead and initialization overhead. This feature requires a nightly compiler -//! and may stop working at any time! -#![cfg_attr(feature = "nightly", feature(maybe_uninit))] #![deny(missing_docs)] +#![deny(rust_2018_compatibility)] +#![deny(rust_2018_idioms)] #![deny(warnings)] #![no_std] -#[cfg(feature = "timer-queue")] -use core::cmp::Ordering; -use core::{fmt, ops}; +use core::ops::Sub; -#[cfg(not(feature = "timer-queue"))] -use cortex_m::peripheral::SYST; use cortex_m::{ interrupt::Nr, peripheral::{CBP, CPUID, DCB, DWT, FPB, FPU, ITM, MPU, NVIC, SCB, TPIU}, }; -pub use cortex_m_rtfm_macros::app; +use cortex_m_rt as _; // vector table +pub use cortex_m_rtic_macros::app; +pub use rtic_core::{Exclusive, Mutex}; +#[cfg(armv7m)] +pub mod cyccnt; #[doc(hidden)] pub mod export; #[doc(hidden)] -#[cfg(feature = "timer-queue")] mod tq; -#[cfg(all(feature = "timer-queue", armv6m))] -compile_error!( - "The `timer-queue` feature is currently not supported on ARMv6-M (`thumbv6m-none-eabi`)" -); - -/// Core peripherals -/// -/// This is `cortex_m::Peripherals` minus the peripherals that the RTFM runtime uses -/// -/// - The `NVIC` field is never present. -/// - When the `timer-queue` feature is enabled the following fields are *not* present: `DWT` and -/// `SYST`. +/// `cortex_m::Peripherals` minus `SYST` #[allow(non_snake_case)] -pub struct Peripherals<'a> { +pub struct Peripherals { /// Cache and branch predictor maintenance operations (not present on Cortex-M0 variants) pub CBP: CBP, /// CPUID pub CPUID: CPUID, - /// Debug Control Block (by value if the `timer-queue` feature is disabled) - #[cfg(feature = "timer-queue")] - pub DCB: &'a mut DCB, - - /// Debug Control Block (borrowed if the `timer-queue` feature is enabled) - #[cfg(not(feature = "timer-queue"))] + /// Debug Control Block pub DCB: DCB, - /// Data Watchpoint and Trace unit (not present if the `timer-queue` feature is enabled) - #[cfg(not(feature = "timer-queue"))] + /// Data Watchpoint and Trace unit pub DWT: DWT, /// Flash Patch and Breakpoint unit (not present on Cortex-M0 variants) @@ -108,253 +79,78 @@ pub struct Peripherals<'a> { /// Memory Protection Unit pub MPU: MPU, - // Nested Vector Interrupt Controller - // pub NVIC: NVIC, - /// System Control Block - pub SCB: &'a mut SCB, + /// Nested Vector Interrupt Controller + pub NVIC: NVIC, - /// SysTick: System Timer (not present if the `timer-queue` is enabled) - #[cfg(not(feature = "timer-queue"))] - pub SYST: SYST, + /// System Control Block + pub SCB: SCB, + // SysTick: System Timer + // pub SYST: SYST, /// Trace Port Interface Unit (not present on Cortex-M0 variants) pub TPIU: TPIU, } -/// A measurement of a monotonically nondecreasing clock. Opaque and useful only with `Duration` -/// -/// This data type is only available when the `timer-queue` feature is enabled -#[derive(Clone, Copy, Debug, Eq, PartialEq)] -#[cfg(feature = "timer-queue")] -pub struct Instant(i32); - -#[cfg(feature = "timer-queue")] -impl Instant { - /// IMPLEMENTATION DETAIL. DO NOT USE - #[doc(hidden)] - pub fn artificial(timestamp: i32) -> Self { - Instant(timestamp) - } - - /// Returns an instant corresponding to "now" - pub fn now() -> Self { - Instant(DWT::get_cycle_count() as i32) - } - - /// Returns the amount of time elapsed since this instant was created. - pub fn elapsed(&self) -> Duration { - Instant::now() - *self - } - - /// Returns the amount of time elapsed from another instant to this one. - pub fn duration_since(&self, earlier: Instant) -> Duration { - let diff = self.0 - earlier.0; - assert!(diff >= 0, "second instant is later than self"); - Duration(diff as u32) - } -} - -#[cfg(feature = "timer-queue")] -impl ops::AddAssign<Duration> for Instant { - fn add_assign(&mut self, dur: Duration) { - debug_assert!(dur.0 < (1 << 31)); - self.0 = self.0.wrapping_add(dur.0 as i32); - } -} - -#[cfg(feature = "timer-queue")] -impl ops::Add<Duration> for Instant { - type Output = Self; - - fn add(mut self, dur: Duration) -> Self { - self += dur; - self - } -} - -#[cfg(feature = "timer-queue")] -impl ops::SubAssign<Duration> for Instant { - fn sub_assign(&mut self, dur: Duration) { - // XXX should this be a non-debug assertion? - debug_assert!(dur.0 < (1 << 31)); - self.0 = self.0.wrapping_sub(dur.0 as i32); - } -} - -#[cfg(feature = "timer-queue")] -impl ops::Sub<Duration> for Instant { - type Output = Self; - - fn sub(mut self, dur: Duration) -> Self { - self -= dur; - self - } -} - -#[cfg(feature = "timer-queue")] -impl ops::Sub<Instant> for Instant { - type Output = Duration; - - fn sub(self, other: Instant) -> Duration { - self.duration_since(other) - } -} - -#[cfg(feature = "timer-queue")] -impl Ord for Instant { - fn cmp(&self, rhs: &Self) -> Ordering { - self.0.wrapping_sub(rhs.0).cmp(&0) - } -} - -#[cfg(feature = "timer-queue")] -impl PartialOrd for Instant { - fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> { - Some(self.cmp(rhs)) - } -} - -/// A `Duration` type to represent a span of time. -/// -/// This data type is only available when the `timer-queue` feature is enabled -#[derive(Clone, Copy, Default, Eq, Ord, PartialEq, PartialOrd)] -#[cfg(feature = "timer-queue")] -pub struct Duration(u32); - -#[cfg(feature = "timer-queue")] -impl Duration { - /// Returns the total number of clock cycles contained by this `Duration` - pub fn as_cycles(&self) -> u32 { - self.0 - } -} - -#[cfg(feature = "timer-queue")] -impl ops::AddAssign for Duration { - fn add_assign(&mut self, dur: Duration) { - self.0 += dur.0; - } -} - -#[cfg(feature = "timer-queue")] -impl ops::Add<Duration> for Duration { - type Output = Self; - - fn add(self, other: Self) -> Self { - Duration(self.0 + other.0) - } -} - -#[cfg(feature = "timer-queue")] -impl ops::SubAssign for Duration { - fn sub_assign(&mut self, rhs: Duration) { - self.0 -= rhs.0; - } -} - -#[cfg(feature = "timer-queue")] -impl ops::Sub<Duration> for Duration { - type Output = Self; - - fn sub(self, rhs: Self) -> Self { - Duration(self.0 - rhs.0) - } -} - -/// Adds the `cycles` method to the `u32` type -/// -/// This trait is only available when the `timer-queue` feature is enabled -#[cfg(feature = "timer-queue")] -pub trait U32Ext { - /// Converts the `u32` value into clock cycles - fn cycles(self) -> Duration; -} - -#[cfg(feature = "timer-queue")] -impl U32Ext for u32 { - fn cycles(self) -> Duration { - Duration(self) - } -} - -/// Memory safe access to shared resources -/// -/// In RTFM, locks are implemented as critical sections that prevent other tasks from *starting*. -/// These critical sections are implemented by temporarily increasing the dynamic priority (see -/// [BASEPRI]) of the current context. Entering and leaving these critical sections is always done -/// in constant time (a few instructions). -/// -/// [BASEPRI]: https://developer.arm.com/products/architecture/cpu-architecture/m-profile/docs/100701/latest/special-purpose-mask-registers -pub trait Mutex { - /// Data protected by the mutex - type T; - - /// Creates a critical section and grants temporary access to the protected data - fn lock<R, F>(&mut self, f: F) -> R - where - F: FnOnce(&mut Self::T) -> R; -} - -impl<'a, M> Mutex for &'a mut M -where - M: Mutex, -{ - type T = M::T; - - fn lock<R, F>(&mut self, f: F) -> R - where - F: FnOnce(&mut Self::T) -> R, - { - (**self).lock(f) - } -} - -/// Newtype over `&'a mut T` that implements the `Mutex` trait -/// -/// The `Mutex` implementation for this type is a no-op, no critical section is created -pub struct Exclusive<'a, T>(pub &'a mut T); - -impl<'a, T> Mutex for Exclusive<'a, T> { - type T = T; - - fn lock<R, F>(&mut self, f: F) -> R - where - F: FnOnce(&mut Self::T) -> R, - { - f(self.0) - } -} - -impl<'a, T> fmt::Debug for Exclusive<'a, T> -where - T: fmt::Debug, -{ - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - (**self).fmt(f) - } -} - -impl<'a, T> fmt::Display for Exclusive<'a, T> -where - T: fmt::Display, -{ - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - (**self).fmt(f) - } -} - -impl<'a, T> ops::Deref for Exclusive<'a, T> { - type Target = T; - - fn deref(&self) -> &T { - self.0 - } -} - -impl<'a, T> ops::DerefMut for Exclusive<'a, T> { - fn deref_mut(&mut self) -> &mut T { - self.0 - } +impl From<cortex_m::Peripherals> for Peripherals { + fn from(p: cortex_m::Peripherals) -> Self { + Self { + CBP: p.CBP, + CPUID: p.CPUID, + DCB: p.DCB, + DWT: p.DWT, + FPB: p.FPB, + FPU: p.FPU, + ITM: p.ITM, + MPU: p.MPU, + NVIC: p.NVIC, + SCB: p.SCB, + TPIU: p.TPIU, + } + } +} + +/// A fraction +pub struct Fraction { + /// The numerator + pub numerator: u32, + + /// The denominator + pub denominator: u32, +} + +/// A monotonic clock / counter +pub trait Monotonic { + /// A measurement of this clock, use `CYCCNT` as a reference implementation for `Instant`. + /// Note that the Instant must be a signed value such as `i32`. + type Instant: Copy + Ord + Sub; + + /// The ratio between the system timer (SysTick) frequency and this clock frequency, i.e. + /// `Monotonic clock * Fraction = System clock` + /// + /// The ratio must be expressed in *reduced* `Fraction` form to prevent overflows. That is + /// `2 / 3` instead of `4 / 6` + fn ratio() -> Fraction; + + /// Returns the current time + /// + /// # Correctness + /// + /// This function is *allowed* to return nonsensical values if called before `reset` is invoked + /// by the runtime. Therefore application authors should *not* call this function during the + /// `#[init]` phase. + fn now() -> Self::Instant; + + /// Resets the counter to *zero* + /// + /// # Safety + /// + /// This function will be called *exactly once* by the RTIC runtime after `#[init]` returns and + /// before tasks can start; this is also the case in multi-core applications. User code must + /// *never* call this function. + unsafe fn reset(); + + /// A `Self::Instant` that represents a count of *zero* + fn zero() -> Self::Instant; } /// Sets the given `interrupt` as pending |