Auto merge of #50 - japaric:singletons, r=japaric

Peripherals as scoped singletons

See this RFC for details: rust-embedded/svd2rust#157

- The first commit adapts this crate to the changes in rust-embedded/cortex-m#65 and rust-embedded/svd2rust#158
- ~~The second commit is an alternative implementation of RFC #47 (there's another implementation in #49. This second commit is not required for RFC157 but let us experiment with safe DMA abstractions.~~ postponed

### TODO

- [x] un-bless peripherals as resources. Peripherals as resources were special cased: if resource listed in e.g. `app.tasks.FOO.resources` didn't appear in `app.resources` then it was assumed to be a peripheral and special code was generated for it. This is no longer required under RFC157.

~~This depends on PR rtic-rs/rtic-syntax#2~~ postponed

Author: homunkulus

Cargo.toml

@@ -10,13 +10,13 @@ keywords = ["arm", "cortex-m"]
 license = "MIT OR Apache-2.0"
 name = "cortex-m-rtfm"
 repository = "https://github.com/japaric/cortex-m-rtfm"
-version = "0.2.2"
+version = "0.3.0"
 
 [dependencies]
-cortex-m = "0.3.1"
+cortex-m = { git = "https://github.com/japaric/cortex-m" }
 untagged-option = "0.1.1"
 rtfm-core = "0.1.0"
-cortex-m-rtfm-macros = "0.2.1"
+cortex-m-rtfm-macros = { path = "macros" }
 
 [target.'cfg(target_arch = "x86_64")'.dev-dependencies]
 compiletest_rs = "0.3.3"
@@ -27,7 +27,8 @@ version = "0.3.3"
 
 [dev-dependencies.stm32f103xx]
 features = ["rt"]
-version = "0.7.5"
+git = "https://github.com/japaric/stm32f103xx"
+# version = "0.8.0"
 
 [profile.release]
 lto = true

examples/generics.rs

@@ -12,6 +12,11 @@ use stm32f103xx::{SPI1, GPIOA};
 app! {
     device: stm32f103xx,
 
+    resources: {
+        static GPIOA: GPIOA;
+        static SPI1: SPI1;
+    },
+
     tasks: {
         EXTI0: {
             path: exti0,
@@ -27,7 +32,12 @@ app! {
     },
 }
 
-fn init(_p: init::Peripherals) {}
+fn init(p: init::Peripherals) -> init::LateResourceValues {
+    init::LateResourceValues {
+        GPIOA: p.device.GPIOA,
+        SPI1: p.device.SPI1,
+    }
+}
 
 fn idle() -> ! {
     loop {

examples/one-task.rs

@@ -7,8 +7,9 @@ extern crate cortex_m;
 extern crate cortex_m_rtfm as rtfm;
 extern crate stm32f103xx;
 
-use cortex_m::peripheral::SystClkSource;
+use cortex_m::peripheral::syst::SystClkSource;
 use rtfm::{app, Threshold};
+use stm32f103xx::GPIOC;
 
 app! {
     device: stm32f103xx,
@@ -35,9 +36,8 @@ app! {
 
             // These are the resources this task has access to.
             //
-            // A resource can be a peripheral like `GPIOC` or a static variable
-            // like `ON`
-            resources: [GPIOC, ON],
+            // The resources listed here must also appear in `app.resources`
+            resources: [ON],
         },
     }
 }
@@ -47,19 +47,20 @@ fn init(p: init::Peripherals, r: init::Resources) {
     r.ON;
 
     // power on GPIOC
-    p.RCC.apb2enr.modify(|_, w| w.iopcen().enabled());
+    p.device.RCC.apb2enr.modify(|_, w| w.iopcen().enabled());
 
     // configure PC13 as output
-    p.GPIOC.bsrr.write(|w| w.bs13().set());
-    p.GPIOC
+    p.device.GPIOC.bsrr.write(|w| w.bs13().set());
+    p.device
+        .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();
+    p.core.SYST.set_clock_source(SystClkSource::Core);
+    p.core.SYST.set_reload(8_000_000); // 1s
+    p.core.SYST.enable_interrupt();
+    p.core.SYST.enable_counter();
 }
 
 fn idle() -> ! {
@@ -74,15 +75,22 @@ fn idle() -> ! {
 //
 // `r` is the set of resources this task has access to. `SYS_TICK::Resources`
 // has one field per resource declared in `app!`.
+#[allow(unsafe_code)]
 fn sys_tick(_t: &mut Threshold, r: SYS_TICK::Resources) {
     // toggle state
     **r.ON = !**r.ON;
 
     if **r.ON {
         // set the pin PC13 high
-        r.GPIOC.bsrr.write(|w| w.bs13().set());
+        // NOTE(unsafe) atomic write to a stateless register
+        unsafe {
+            (*GPIOC::ptr()).bsrr.write(|w| w.bs13().set());
+        }
     } else {
         // set the pin PC13 low
-        r.GPIOC.bsrr.write(|w| w.br13().reset());
+        // NOTE(unsafe) atomic write to a stateless register
+        unsafe {
+            (*GPIOC::ptr()).bsrr.write(|w| w.br13().reset());
+        }
     }
 }

examples/zero-tasks.rs

@@ -25,8 +25,9 @@ app! {
 // this function.
 fn init(p: init::Peripherals) {
     // This function has access to all the peripherals of the device
-    p.GPIOA;
-    p.RCC;
+    p.core.SYST;
+    p.device.GPIOA;
+    p.device.RCC;
     // ..
 }
 

macros/src/check.rs

@@ -63,16 +63,15 @@ pub fn app(app: check::App) -> Result<App> {
         tasks: app.tasks
             .into_iter()
             .map(|(k, v)| {
-                let v = ::check::task(k.as_ref(), v)
-                    .chain_err(|| format!("checking task `{}`", k))?;
+                let v =
+                    ::check::task(k.as_ref(), v).chain_err(|| format!("checking task `{}`", k))?;
 
                 Ok((k, v))
             })
             .collect::<Result<_>>()?,
     };
 
-    ::check::resources(&app)
-        .chain_err(|| "checking `resources`")?;
+    ::check::resources(&app).chain_err(|| "checking `resources`")?;
 
     Ok(app)
 }
@@ -93,6 +92,17 @@ fn resources(app: &App) -> Result<()> {
         bail!("resource `{}` is unused", resource);
     }
 
+    for (name, task) in &app.tasks {
+        for resource in &task.resources {
+            ensure!(
+                app.resources.contains_key(&resource),
+                "task {} contains an undeclared resource with name {}",
+                name,
+                resource
+            );
+        }
+    }
+
     Ok(())
 }