1 files changed, 91 insertions, 0 deletions
diff --git a/examples/one-task.rs b/examples/one-task.rs
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+//! An application with one task
+
+#![deny(unsafe_code)]
+#![feature(const_fn)]
+#![feature(proc_macro)]
+#![no_std]
+
+extern crate cortex_m;
+#[macro_use(task)]
+extern crate cortex_m_rtfm as rtfm;
+extern crate stm32f103xx;
+
+use cortex_m::peripheral::SystClkSource;
+use rtfm::{app, Threshold};
+
+app! {
+    device: stm32f103xx,
+
+    // Here tasks are declared
+    //
+    // Each task corresponds to an interrupt or an exception. Every time the
+    // interrupt or exception becomes *pending* the corresponding task handler
+    // will be executed.
+    tasks: {
+        // Here we declare that we'll use the SYS_TICK exception as a task
+        SYS_TICK: {
+            // This is the priority of the task.
+            // 1 is the lowest priority a task can have.
+            // The maximum priority is determined by the number of priority bits
+            // the device has. This device has 4 priority bits so 16 is the
+            // maximum value.
+            priority: 1,
+
+            // These are the *resources* associated with this task
+            //
+            // The peripherals that the task needs can be listed here
+            resources: [GPIOC],
+        },
+    }
+}
+
+fn init(p: init::Peripherals) {
+    // power on GPIOC
+    p.RCC.apb2enr.modify(|_, w| w.iopcen().enabled());
+
+    // configure PC13 as output
+    p.GPIOC.bsrr.write(|w| w.bs13().set());
+    p.GPIOC
+        .crh
+        .modify(|_, w| w.mode13().output().cnf13().push());
+
+    // configure the system timer to generate one interrupt every second
+    p.SYST.set_clock_source(SystClkSource::Core);
+    p.SYST.set_reload(8_000_000); // 1s
+    p.SYST.enable_interrupt();
+    p.SYST.enable_counter();
+}
+
+fn idle() -> ! {
+    loop {
+        rtfm::wfi();
+    }
+}
+
+// This binds the `sys_tick` handler to the `SYS_TICK` task
+//
+// This particular handler has local state associated to it. The value of the
+// `STATE` variable will be preserved across invocations of this handler
+task!(SYS_TICK, sys_tick, Locals {
+    static STATE: bool = false;
+});
+
+// This is the task handler of the SYS_TICK exception
+//
+// `t` is the preemption threshold token. We won't use it this time.
+// `l` is the data local to this task. The type here must match the one declared
+// in `task!`.
+// `r` is the resources this task has access to. `SYS_TICK::Resources` has one
+// field per resource declared in `app!`.
+fn sys_tick(_t: &mut Threshold, l: &mut Locals, r: SYS_TICK::Resources) {
+    // toggle state
+    *l.STATE = !*l.STATE;
+
+    if *l.STATE {
+        // set the pin PC13 high
+        r.GPIOC.bsrr.write(|w| w.bs13().set());
+    } else {
+        // set the pin PC13 low
+        r.GPIOC.bsrr.write(|w| w.br13().reset());
+    }
+}