Improve support for ultra-low power scheduling, including hibernation via suspend/resume operations.

Add two C++ and C examples which demonstrate how to achieve ultra-low power scheduling based on STM32F407G-DISC1 board.

Author: dmitrykos

build/benchmark/eclipse/perf-stm32f407g-disc1-stk/src/main.cpp

@@ -36,7 +36,7 @@ extern "C" void SysTick_Handler()
         g_Kernel.GetPlatform()->ProcessTick();
 }
 
-class BenchTask : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
+class BenchTask final : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
 {
 public:
     BenchTask() : m_id(~0), m_exited(false) {}
@@ -45,7 +45,7 @@ class BenchTask : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
     bool IsExited() const { return m_exited; }
 
 private:
-    void Run()
+    void Run() override
     {
         uint32_t index = m_id;
 
@@ -62,13 +62,12 @@ class BenchTask : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
     uint8_t       m_id;
     volatile bool m_exited;
 };
-
 static BenchTask g_Tasks[_STK_BENCH_TASK_MAX];
 
-class ResultTask : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
+class ResultTask final : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
 {
 private:
-    void Run()
+    void Run() override
     {
         while (g_Ticks < _STK_BENCH_WINDOW + 2)
         {
@@ -85,7 +84,6 @@ class ResultTask : public Task<_STK_BENCH_STACK_SIZE, ACCESS_PRIVILEGED>
         Crc32Bench::ShowResults();
     }
 };
-
 static ResultTask g_TaskResult;
 
 int main(int argc, char **argv)

build/example/hrt/example.cpp

@@ -32,7 +32,7 @@ enum { TASK_STACK_SIZE = 256 };
 static stk::sync::PipeT<uint8_t, 1> g_LedPipe[LED_MAX];
 
 template <stk::EAccessMode _AccessMode>
-class HwLedTask : public stk::Task<TASK_STACK_SIZE, _AccessMode>
+class HwLedTask final : public stk::Task<TASK_STACK_SIZE, _AccessMode>
 {
     uint8_t m_task_id;
 
@@ -41,7 +41,7 @@ class HwLedTask : public stk::Task<TASK_STACK_SIZE, _AccessMode>
     {}
 
 private:
-    void Run()
+    void Run() override
     {
         for (;;)
         {
@@ -69,10 +69,9 @@ class HwLedTask : public stk::Task<TASK_STACK_SIZE, _AccessMode>
 };
 
 template <stk::EAccessMode _AccessMode>
-class CtrlTask : public stk::Task<TASK_STACK_SIZE, _AccessMode>
+class CtrlTask final : public stk::Task<TASK_STACK_SIZE, _AccessMode>
 {
-private:
-    void Run()
+    void Run() override
     {
         uint8_t led = 0;
         stk::time::PeriodicTrigger trigger(1000, true);
@@ -104,17 +103,9 @@ class CtrlTask : public stk::Task<TASK_STACK_SIZE, _AccessMode>
 };
 
 // optional: you can override sleep and hard fault default behaviors
-class PlatformEventHandler : public stk::IPlatform::IEventOverrider
+class PlatformEventHandler final : public stk::IPlatform::IEventOverrider
 {
-private:
-    bool OnSleep()
-    {
-        // if handled inside this function then return true, otherwise event will be handled by the driver
-        // note: if returned false once this function will not be called again until Kernel is re-started
-        return false;
-    }
-
-    bool OnHardFault()
+    bool OnHardFault() override
     {
         // switch on Red LED as indication of the error
         Led::SwitchOnExclusive(Led::RED);