cc3200: Shrink the FreeRTOS heap and place TCB+stack in freed location.

The 16k FreeRTOS heap originally had all TCBs and stacks dynamically
allocated within it (plus semaphores and some other things).  Now that
xTaskCreateStatic is used instead of xTaskCreate, the TCBs and stacks
are allocated statically and no longer use any of the FreeRTOS heap.
Therefore, the FreeRTOS stack can be shrunk by the amount that has been
made static.  Furthermore, the TCBs and stack that are now static should
be placed in the .rtos_heaps section of RAM because this RAM is treated
specially by the bootloader (the bootloader executes from the first 16k
of RAM and loads the firmware into the section starting after the 16k).

After this patch the FreeRTOS heap (ucHeap) is 7200 bytes.  The memory
available for the MicroPython heap is 54936 bytes (including GC overhead).

cc3200/FreeRTOS/FreeRTOSConfig.h

@@ -84,7 +84,13 @@
 #define configCPU_CLOCK_HZ				        ( ( unsigned long ) 80000000 )
 #define configTICK_RATE_HZ				        ( ( TickType_t ) 1000 )
 #define configMINIMAL_STACK_SIZE		        ( ( unsigned short ) 72 )
-#define configTOTAL_HEAP_SIZE			        ( ( size_t ) ( 16384 ) )
+#define configTOTAL_HEAP_SIZE			        ( ( size_t ) ( \
+    16384 /* 16kbytes for FreeRTOS data structures and heap */ \
+    - sizeof(StaticTask_t) - configMINIMAL_STACK_SIZE * sizeof(StackType_t) /* TCB+stack for idle task */ \
+    - sizeof(StaticTask_t) - 1024 /* TCB+stack for servers task */ \
+    - sizeof(StaticTask_t) - 6656 /* TCB+stack for main MicroPython task */ \
+    - sizeof(StaticTask_t) - 896 /* TCB+stack for simplelink spawn task */ \
+    ) )
 #define configMAX_TASK_NAME_LEN			        ( 8 )
 #define configUSE_TRACE_FACILITY		        0
 #define configUSE_16_BIT_TICKS			        0

cc3200/main.c

@@ -50,6 +50,10 @@
  DECLARE PRIVATE DATA
  ******************************************************************************/
 
+// This is the static memory (TCB and stack) for the idle task
+static StaticTask_t xIdleTaskTCB __attribute__ ((section (".rtos_heap")));
+static StackType_t uxIdleTaskStack[configMINIMAL_STACK_SIZE] __attribute__ ((section (".rtos_heap"))) __attribute__((aligned (8)));
+
 /******************************************************************************
  DECLARE PUBLIC DATA
  ******************************************************************************/
@@ -61,8 +65,8 @@ OsiTaskHandle   mpTaskHandle;
 uint8_t ucHeap[ configTOTAL_HEAP_SIZE ] __attribute__ ((section (".rtos_heap"))) __attribute__((aligned (8)));
 
 // This is the static memory (TCB and stack) for the main MicroPython task
-StaticTask_t mpTaskTCB;
-StackType_t mpTaskStack[MICROPY_TASK_STACK_LEN] __attribute__((aligned (8)));
+StaticTask_t mpTaskTCB __attribute__ ((section (".rtos_heap")));
+StackType_t mpTaskStack[MICROPY_TASK_STACK_LEN] __attribute__ ((section (".rtos_heap"))) __attribute__((aligned (8)));
 
 /******************************************************************************
  DEFINE PUBLIC FUNCTIONS
@@ -105,9 +109,6 @@ void stoupper (char *str) {
 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;
     *pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;

cc3200/serverstask.c

@@ -67,8 +67,11 @@ static volatile bool sleep_sockets = false;
 /******************************************************************************
  DECLARE PUBLIC DATA
  ******************************************************************************/
-StaticTask_t svTaskTCB;
-StackType_t svTaskStack[SERVERS_STACK_LEN] __attribute__((aligned (8)));
+
+// This is the static memory (TCB and stack) for the servers task
+StaticTask_t svTaskTCB __attribute__ ((section (".rtos_heap")));
+StackType_t svTaskStack[SERVERS_STACK_LEN] __attribute__ ((section (".rtos_heap"))) __attribute__((aligned (8)));
+
 char servers_user[SERVERS_USER_PASS_LEN_MAX + 1];
 char servers_pass[SERVERS_USER_PASS_LEN_MAX + 1];
 

cc3200/simplelink/oslib/osi_freertos.c

@@ -62,8 +62,8 @@ TaskHandle_t xSimpleLinkSpawnTaskHndl = NULL;
 #define SL_SPAWN_MAX_WAIT_MS        ( 200 )
 
 // This is the static memory (TCB and stack) for the SL spawn task
-static StaticTask_t spawnTaskTCB;
-static portSTACK_TYPE spawnTaskStack[896 / sizeof(portSTACK_TYPE)] __attribute__((aligned (8)));
+static StaticTask_t spawnTaskTCB __attribute__ ((section (".rtos_heap")));
+static portSTACK_TYPE spawnTaskStack[896 / sizeof(portSTACK_TYPE)] __attribute__ ((section (".rtos_heap"))) __attribute__((aligned (8)));
 
 /*!
 	\brief 	This function registers an interrupt in NVIC table