Add default implementations of vApplicationGetIdleTaskMemory and vApplicationGetTimerTaskMemory (#790)

This PR introduces configKERNEL_PROVIDED_STATIC_MEMORY option
which the application can set to 1 to use the default implementations
of vApplicationGetIdleTaskMemory and vApplicationGetTimerTaskMemory
functions.

If the application enables static allocation (i.e. sets
configUSE_STATIC_ALLOCATION to 1) and does not provide the above 2
functions, it will result in linker error. The application has two options:

1. Set configKERNEL_PROVIDED_STATIC_MEMORY to 1 to use the default
    implementations of these functions.
2. Provide implementations of these 2 functions.

Note that default definitions are only available for non-MPU ports. The
reason is that the stack alignment requirements vary for different
architectures.

include/FreeRTOS.h

@@ -1131,6 +1131,10 @@
     #define configSUPPORT_STATIC_ALLOCATION    0
 #endif
 
+#ifndef configKERNEL_PROVIDED_STATIC_MEMORY
+    #define configKERNEL_PROVIDED_STATIC_MEMORY    0
+#endif
+
 #ifndef configSUPPORT_DYNAMIC_ALLOCATION
     /* Defaults to 1 for backward compatibility. */
     #define configSUPPORT_DYNAMIC_ALLOCATION    1

tasks.c

@@ -7653,3 +7653,52 @@ static void prvAddCurrentTaskToDelayedList( TickType_t xTicksToWait,
     #endif
 
 #endif /* if ( configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H == 1 ) */
+/*-----------------------------------------------------------*/
+
+#if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configKERNEL_PROVIDED_STATIC_MEMORY == 1 ) && ( portUSING_MPU_WRAPPERS == 0 ) )
+
+/*
+ * This is the kernel provided implementation of vApplicationGetIdleTaskMemory()
+ * to provide the memory that is used by the Idle task. It is used when
+ * configKERNEL_PROVIDED_STATIC_MEMORY is set to 1. The application can provide
+ * it's own implementation of vApplicationGetIdleTaskMemory by setting
+ * configKERNEL_PROVIDED_STATIC_MEMORY to 0 or leaving it undefined.
+ */
+    void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
+                                        StackType_t ** ppxIdleTaskStackBuffer,
+                                        uint32_t * pulIdleTaskStackSize )
+    {
+        static StaticTask_t xIdleTaskTCB;
+        static StackType_t uxIdleTaskStack[ configMINIMAL_STACK_SIZE ];
+
+        *ppxIdleTaskTCBBuffer = &( xIdleTaskTCB );
+        *ppxIdleTaskStackBuffer = &( uxIdleTaskStack[ 0 ] );
+        *pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
+    }
+
+#endif /* #if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configKERNEL_PROVIDED_STATIC_MEMORY == 1 ) && ( portUSING_MPU_WRAPPERS == 0 ) ) */
+/*-----------------------------------------------------------*/
+
+#if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configKERNEL_PROVIDED_STATIC_MEMORY == 1 ) && ( portUSING_MPU_WRAPPERS == 0 ) )
+
+/*
+ * This is the kernel provided implementation of vApplicationGetTimerTaskMemory()
+ * to provide the memory that is used by the Timer service task. It is used when
+ * configKERNEL_PROVIDED_STATIC_MEMORY is set to 1. The application can provide
+ * it's own implementation of vApplicationGetTimerTaskMemory by setting
+ * configKERNEL_PROVIDED_STATIC_MEMORY to 0 or leaving it undefined.
+ */
+    void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
+                                         StackType_t ** ppxTimerTaskStackBuffer,
+                                         uint32_t * pulTimerTaskStackSize )
+    {
+        static StaticTask_t xTimerTaskTCB;
+        static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];
+
+        *ppxTimerTaskTCBBuffer = &( xTimerTaskTCB );
+        *ppxTimerTaskStackBuffer = &( uxTimerTaskStack[ 0 ] );
+        *pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
+    }
+
+#endif /* #if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configKERNEL_PROVIDED_STATIC_MEMORY == 1 ) && ( portUSING_MPU_WRAPPERS == 0 ) ) */
+/*-----------------------------------------------------------*/