diff --git a/examples/event-task.rs b/examples/event-task.rs
index 3a51c5b4f6..0f51bbfaf3 100644
--- a/examples/event-task.rs
+++ b/examples/event-task.rs
@@ -4,14 +4,12 @@
 #![no_main]
 #![no_std]
 
-extern crate cortex_m;
 #[macro_use]
 extern crate cortex_m_rt as rt;
 extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use rt::ExceptionFrame;
 use rtfm::app;
 
@@ -30,13 +28,6 @@ fn init(mut _ctxt: init::Context) -> init::LateResources {
     init::LateResources {}
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn exti0(_ctxt: exti0::Context) {}
 
 exception!(HardFault, hard_fault);
diff --git a/examples/idle.rs b/examples/idle.rs
new file mode 100644
index 0000000000..e4303b9161
--- /dev/null
+++ b/examples/idle.rs
@@ -0,0 +1,48 @@
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![feature(proc_macro)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m;
+#[macro_use]
+extern crate cortex_m_rt;
+extern crate cortex_m_rtfm as rtfm;
+extern crate panic_semihosting;
+extern crate stm32f103xx;
+
+use cortex_m::asm;
+use cortex_m_rt::ExceptionFrame;
+use rtfm::app;
+
+app! {
+    device: stm32f103xx,
+
+    idle: {},
+}
+
+#[inline(always)]
+fn init(_ctxt: init::Context) -> init::LateResources {
+    init::LateResources {}
+}
+
+#[inline(always)]
+fn idle(_ctxt: idle::Context) -> ! {
+    loop {
+        asm::wfi();
+    }
+}
+
+exception!(HardFault, hard_fault);
+
+#[inline(always)]
+fn hard_fault(ef: &ExceptionFrame) -> ! {
+    panic!("HardFault at {:#?}", ef);
+}
+
+exception!(*, default_handler);
+
+#[inline(always)]
+fn default_handler(irqn: i16) {
+    panic!("Unhandled exception (IRQn = {})", irqn);
+}
diff --git a/examples/minimal.rs b/examples/minimal.rs
index 7c7b0b823d..da76629dc8 100644
--- a/examples/minimal.rs
+++ b/examples/minimal.rs
@@ -4,14 +4,12 @@
 #![no_main]
 #![no_std]
 
-extern crate cortex_m;
 #[macro_use]
 extern crate cortex_m_rt;
 extern crate cortex_m_rtfm as rtfm;
 extern crate panic_semihosting;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m_rt::ExceptionFrame;
 use rtfm::app;
 
@@ -24,13 +22,6 @@ fn init(_ctxt: init::Context) -> init::LateResources {
     init::LateResources {}
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 exception!(HardFault, hard_fault);
 
 #[inline(always)]
diff --git a/examples/periodic-payload.rs b/examples/periodic-payload.rs
index 9697934fd9..e99001ea58 100644
--- a/examples/periodic-payload.rs
+++ b/examples/periodic-payload.rs
@@ -46,7 +46,6 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
 use rtfm::app;
@@ -85,13 +84,6 @@ fn init(mut ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn a(mut ctxt: a::Context) {
     let now = DWT::get_cycle_count();
     let input = ctxt.input;
diff --git a/examples/periodic-preemption-payload.rs b/examples/periodic-preemption-payload.rs
index 0207b4546e..1397ac2f98 100644
--- a/examples/periodic-preemption-payload.rs
+++ b/examples/periodic-preemption-payload.rs
@@ -75,10 +75,9 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
-use rtfm::{app, Resource};
+use rtfm::app;
 
 app! {
     device: stm32f103xx,
@@ -122,13 +121,6 @@ fn init(mut ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn a(mut ctxt: a::Context) {
     let now = DWT::get_cycle_count();
 
diff --git a/examples/periodic-preemption.rs b/examples/periodic-preemption.rs
index e1e450e69c..3ca458061b 100644
--- a/examples/periodic-preemption.rs
+++ b/examples/periodic-preemption.rs
@@ -76,7 +76,6 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
 use rtfm::{app, Resource};
@@ -121,13 +120,6 @@ fn init(mut ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn a(mut ctxt: a::Context) {
     let now = DWT::get_cycle_count();
 
diff --git a/examples/periodic.rs b/examples/periodic.rs
index 90b3abeba6..875d5b896d 100644
--- a/examples/periodic.rs
+++ b/examples/periodic.rs
@@ -42,10 +42,8 @@ extern crate cortex_m;
 extern crate cortex_m_rt as rt;
 extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
-// extern crate panic_itm;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
 use rtfm::app;
@@ -83,13 +81,6 @@ fn init(mut ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn a(mut ctxt: a::Context) {
     let now = DWT::get_cycle_count();
 
diff --git a/examples/schedule-after-from-event-task.rs b/examples/schedule-after-from-event-task.rs
index 2e666a7d56..de7da763b8 100644
--- a/examples/schedule-after-from-event-task.rs
+++ b/examples/schedule-after-from-event-task.rs
@@ -11,7 +11,6 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
 use rtfm::app;
@@ -47,13 +46,6 @@ fn init(ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn exti0(mut ctxt: exti0::Context) {
     let now = DWT::get_cycle_count();
     iprintln!(
diff --git a/examples/schedule-after.rs b/examples/schedule-after.rs
index dc7946b9df..f8a00a1947 100644
--- a/examples/schedule-after.rs
+++ b/examples/schedule-after.rs
@@ -11,7 +11,6 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use rt::ExceptionFrame;
 use rtfm::app;
 
@@ -37,20 +36,11 @@ fn init(_ctxt: init::Context) -> init::LateResources {
     init::LateResources {}
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn exti0(mut ctxt: exti0::Context) {
     ctxt.tasks.a.schedule_after(&mut ctxt.priority, 1 * S).ok();
 }
 
-fn a(_ctxt: a::Context) {
-    asm::bkpt();
-}
+fn a(_ctxt: a::Context) {}
 
 exception!(HardFault, hard_fault);
 
diff --git a/examples/schedule-now-from-event-task.rs b/examples/schedule-now-from-event-task.rs
index 98531ddfa3..d900e8fe3c 100644
--- a/examples/schedule-now-from-event-task.rs
+++ b/examples/schedule-now-from-event-task.rs
@@ -11,7 +11,6 @@ extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use cortex_m::peripheral::{DWT, ITM};
 use rt::ExceptionFrame;
 use rtfm::app;
@@ -45,13 +44,6 @@ fn init(ctxt: init::Context) -> init::LateResources {
     init::LateResources { ITM: ctxt.core.ITM }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn exti0(mut ctxt: exti0::Context) {
     let now = DWT::get_cycle_count();
     iprintln!(
diff --git a/examples/schedule-now.rs b/examples/schedule-now.rs
index f16539b2b9..c8fca6d51c 100644
--- a/examples/schedule-now.rs
+++ b/examples/schedule-now.rs
@@ -49,15 +49,8 @@ fn init(mut ctxt: init::Context) -> init::LateResources {
     init::LateResources {}
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn exti0(mut ctxt: exti0::Context) {
-    ctxt.tasks.a.schedule_now(&mut ctxt.priority).ok();
+    ctxt.tasks.a.schedule_now(&mut ctxt.priority).unwrap();
 }
 
 fn a(_ctxt: a::Context) {
diff --git a/examples/user-struct.rs b/examples/user-struct.rs
index 2efb98f32e..9a85eaf30c 100644
--- a/examples/user-struct.rs
+++ b/examples/user-struct.rs
@@ -4,14 +4,12 @@
 #![no_main]
 #![no_std]
 
-extern crate cortex_m;
 #[macro_use]
 extern crate cortex_m_rt as rt;
 extern crate cortex_m_rtfm as rtfm;
 extern crate panic_abort;
 extern crate stm32f103xx;
 
-use cortex_m::asm;
 use rt::ExceptionFrame;
 use rtfm::app;
 
@@ -48,13 +46,6 @@ fn init(_ctxt: init::Context) -> init::LateResources {
     init::LateResources { BAR: Foo(0) }
 }
 
-#[inline(always)]
-fn idle(_ctxt: idle::Context) -> ! {
-    loop {
-        asm::wfi();
-    }
-}
-
 fn a(_ctxt: a::Context) {}
 
 fn b(_ctxt: b::Context) {}
diff --git a/macros/src/analyze.rs b/macros/src/analyze.rs
index c901da9ab2..3bfc72f36b 100644
--- a/macros/src/analyze.rs
+++ b/macros/src/analyze.rs
@@ -70,11 +70,17 @@ pub fn app(app: &App) -> Context {
     }
 
     // resources
-    for (priority, resource) in app.idle.resources.iter().map(|res| (0, res)).chain(
-        app.tasks
+    let empty = HashSet::new();
+    for (priority, resource) in
+        app.idle
+            .as_ref()
+            .map(|idle| &idle.resources)
+            .unwrap_or(&empty)
             .iter()
-            .flat_map(|(name, task)| task.resources.iter().map(move |res| (task.priority, res))),
-    ) {
+            .map(|res| (0, res))
+            .chain(app.tasks.iter().flat_map(|(name, task)| {
+                task.resources.iter().map(move |res| (task.priority, res))
+            })) {
         let ceiling = ceilings
             .resources
             .entry(*resource)
diff --git a/macros/src/trans.rs b/macros/src/trans.rs
index 15b6d0af07..7e14fdb7ff 100644
--- a/macros/src/trans.rs
+++ b/macros/src/trans.rs
@@ -15,6 +15,7 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
 
     root.push(quote! {
         extern crate cortex_m_rtfm as #k;
+        #[allow(unused_imports)]
         use #k::Resource as _cortex_m_rtfm_Resource;
     });
 
@@ -90,9 +91,11 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
         }
 
         let ty = &resource.ty;
-        let expr = resource.expr.as_ref().map(|e| quote!(#e)).unwrap_or_else(|| {
-            quote!(unsafe { #k::_impl::uninitialized() })
-        });
+        let expr = resource
+            .expr
+            .as_ref()
+            .map(|e| quote!(#e))
+            .unwrap_or_else(|| quote!(unsafe { #k::_impl::uninitialized() }));
 
         // TODO replace this with a call to `heapless::singleton!` when it doesn't require a feature
         // gate in the user code
@@ -942,7 +945,7 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
                 FPU: p.FPU,
                 ITM: p.ITM,
                 MPU: p.MPU,
-                SCB: p.SCB,
+                SCB: &mut p.SCB,
                 SYST: p.SYST,
                 TPIU: p.TPIU,
             }
@@ -1010,13 +1013,10 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
         })
         .collect::<Vec<_>>();
 
-    let (bl, lt) = if cfg!(feature = "timer-queue") {
-        (
-            Some(quote!(let _bl = ::#k::_impl::Instant(0);)),
-            Some(quote!('a)),
-        )
+    let bl = if cfg!(feature = "timer-queue") {
+        Some(quote!(let _bl = ::#k::_impl::Instant(0);))
     } else {
-        (None, None)
+        None
     };
     root.push(quote! {
         #[allow(non_snake_case)]
@@ -1032,8 +1032,8 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
             pub use ::_ZN4init13LateResourcesE as LateResources;
 
             #[allow(dead_code)]
-            pub struct Context<#lt> {
-                pub core: ::#k::_impl::Peripherals<#lt>,
+            pub struct Context<'a> {
+                pub core: ::#k::_impl::Peripherals<'a>,
                 pub device: Device,
                 pub resources: Resources,
                 pub tasks: Tasks,
@@ -1041,8 +1041,8 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
             }
 
             #[allow(unsafe_code)]
-            impl<#lt> Context<#lt> {
-                pub unsafe fn new(core: ::#k::_impl::Peripherals<#lt>) -> Self {
+            impl<'a> Context<'a> {
+                pub unsafe fn new(core: ::#k::_impl::Peripherals<'a>) -> Self {
                     Context {
                         tasks: Tasks::new(),
                         core,
@@ -1138,6 +1138,13 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
         });
     }
 
+    if app.idle.is_none() {
+        post_init.push(quote! {
+            // Set SLEEPONEXIT
+            p.SCB.scr.modify(|r| r | (1 << 1));
+        });
+    }
+
     if needs_tq {
         post_init.push(quote! {
             // Set the system time to zero
@@ -1147,99 +1154,112 @@ pub fn app(ctxt: &Context, app: &App) -> Tokens {
     }
 
     /* idle */
-    let res_fields = app.idle
-        .resources
-        .iter()
-        .map(|res| {
-            if ctxt.ceilings.resources()[res].is_owned() {
-                let ty = &app.resources[res].ty;
+    if let Some(idle) = app.idle.as_ref() {
+        let res_fields = idle.resources
+            .iter()
+            .map(|res| {
+                if ctxt.ceilings.resources()[res].is_owned() {
+                    let ty = &app.resources[res].ty;
 
-                quote!(pub #res: &'static mut #ty)
-            } else {
-                quote!(pub #res: _resource::#res)
-            }
-        })
-        .collect::<Vec<_>>();
+                    quote!(pub #res: &'static mut #ty)
+                } else {
+                    quote!(pub #res: _resource::#res)
+                }
+            })
+            .collect::<Vec<_>>();
 
-    let res_exprs = app.idle
-        .resources
-        .iter()
-        .map(|res| {
-            if ctxt.ceilings.resources()[res].is_owned() {
-                quote!(#res: _resource::#res::_var())
-            } else {
-                quote!(#res: _resource::#res::new())
-            }
-        })
-        .collect::<Vec<_>>();
+        let res_exprs = idle.resources
+            .iter()
+            .map(|res| {
+                if ctxt.ceilings.resources()[res].is_owned() {
+                    quote!(#res: _resource::#res::_var())
+                } else {
+                    quote!(#res: _resource::#res::new())
+                }
+            })
+            .collect::<Vec<_>>();
 
-    root.push(quote! {
-        mod idle {
-            #[allow(unused_imports)]
-            use ::#k::Resource;
+        root.push(quote! {
+            mod idle {
+                #[allow(unused_imports)]
+                use ::#k::Resource;
 
-            #[allow(dead_code)]
-            pub struct Context {
-                pub resources: Resources,
-                pub priority: ::#k::Priority<::#k::_impl::U0>,
-            }
+                #[allow(dead_code)]
+                pub struct Context {
+                    pub resources: Resources,
+                    pub priority: ::#k::Priority<::#k::_impl::U0>,
+                }
 
-            #[allow(unsafe_code)]
-            impl Context {
-                pub unsafe fn new() -> Self {
-                    Context {
-                        resources: Resources::new(),
-                        priority: ::#k::Priority::_new(),
+                #[allow(unsafe_code)]
+                impl Context {
+                    pub unsafe fn new() -> Self {
+                        Context {
+                            resources: Resources::new(),
+                            priority: ::#k::Priority::_new(),
+                        }
+                    }
+                }
+
+                #[allow(non_snake_case)]
+                pub struct Resources {
+                    #(#res_fields,)*
+                }
+
+                #[allow(unsafe_code)]
+                impl Resources {
+                    unsafe fn new() -> Self {
+                        Resources {
+                            #(#res_exprs,)*
+                        }
                     }
                 }
             }
-
-            #[allow(non_snake_case)]
-            pub struct Resources {
-                #(#res_fields,)*
-            }
-
-            #[allow(unsafe_code)]
-            impl Resources {
-                unsafe fn new() -> Self {
-                    Resources {
-                        #(#res_exprs,)*
-                    }
-                }
-            }
-        }
-    });
+        });
+    }
 
     /* main */
-    let idle = &app.idle.path;
     let init = &app.init.path;
+    let mut main = vec![quote! {
+        #[allow(unused_imports)]
+        use ::#k::Resource;
+        #[allow(unused_imports)]
+        use #device::Interrupt;
+
+        let init: fn(init::Context) -> init::LateResources = #init;
+
+        ::#k::_impl::interrupt::disable();
+
+        let mut p = ::#k::_impl::steal();
+
+        #(#pre_init)*
+
+        let _lr = init(init::Context::new(#core));
+
+        #(#post_init)*
+
+        ::#k::_impl::interrupt::enable();
+    }];
+
+    if let Some(idle) = app.idle.as_ref().map(|idle| &idle.path) {
+        main.push(quote! {
+            let idle: fn(idle::Context) -> ! = #idle;
+            idle(idle::Context::new())
+        });
+    } else {
+        main.push(quote! {
+            loop {
+                #k::_impl::asm::wfi();
+            }
+        });
+    }
+
     root.push(quote! {
         #[allow(unsafe_code)]
         #[allow(unused_mut)]
         #[deny(const_err)]
         #[no_mangle]
         pub unsafe extern "C" fn main() -> ! {
-            #[allow(unused_imports)]
-            use ::#k::Resource;
-            #[allow(unused_imports)]
-            use #device::Interrupt;
-
-            let init: fn(init::Context) -> init::LateResources = #init;
-            let idle: fn(idle::Context) -> ! = #idle;
-
-            ::#k::_impl::interrupt::disable();
-
-            let mut p = ::#k::_impl::steal();
-
-            #(#pre_init)*
-
-            let _lr = init(init::Context::new(#core));
-
-            #(#post_init)*
-
-            ::#k::_impl::interrupt::enable();
-
-            idle(idle::Context::new())
+            #(#main)*
         }
     });
 
diff --git a/src/_impl/mod.rs b/src/_impl/mod.rs
index 79bf034320..6739dffd66 100644
--- a/src/_impl/mod.rs
+++ b/src/_impl/mod.rs
@@ -2,15 +2,15 @@ use core::mem;
 
 pub use self::instant::Instant;
 pub use self::tq::{dispatch, NotReady, TimerQueue};
-pub use cortex_m::interrupt;
 use cortex_m::interrupt::Nr;
 pub use cortex_m::peripheral::syst::SystClkSource;
 use cortex_m::peripheral::{CBP, CPUID, DCB, FPB, FPU, ITM, MPU, NVIC, SCB, TPIU};
 #[cfg(not(feature = "timer-queue"))]
 use cortex_m::peripheral::{DWT, SYST};
+pub use cortex_m::{asm, interrupt};
 pub use heapless::object_pool::{Singleton, Uninit};
-pub use stable_deref_trait::StableDeref;
 use heapless::RingBuffer as Queue;
+pub use stable_deref_trait::StableDeref;
 pub use typenum::consts::*;
 pub use typenum::{Max, Maximum, Unsigned};