cc3200: Place functions only used while booting in a special section.

Such functions are never used after MicroPython has started, and they
remain in RAM wasting space. Now they are placed in a special section
named "boot" which sits just before the heap, allowing us to extend
the effective heap area up to the new boot section. Right now, this
gives us back ~1K, but in the future, more functions might end up in
there as well.

cc3200/FreeRTOS/Source/portable/GCC/ARM_CM3/port.c

@@ -202,6 +202,7 @@ static void prvTaskExitError( void );
 /*
  * See header file for description.
  */
+__attribute__ ((section (".boot")))
 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
 {
 	/* Simulate the stack frame as it would be created by a context switch
@@ -220,6 +221,7 @@ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t px
 }
 /*-----------------------------------------------------------*/
 
+__attribute__ ((section (".boot")))
 static void prvTaskExitError( void )
 {
 	/* A function that implements a task must not exit or attempt to return to
@@ -254,6 +256,7 @@ void vPortSVCHandler( void )
 }
 /*-----------------------------------------------------------*/
 
+__attribute__ ((section (".boot")))
 static void prvPortStartFirstTask( void )
 {
 	__asm volatile(
@@ -274,6 +277,7 @@ static void prvPortStartFirstTask( void )
 /*
  * See header file for description.
  */
+__attribute__ ((section (".boot")))
 BaseType_t xPortStartScheduler( void )
 {
 	/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0.
@@ -643,6 +647,7 @@ void xPortSysTickHandler( void )
  * Setup the systick timer to generate the tick interrupts at the required
  * frequency.
  */
+__attribute__ ((section (".boot")))
 __attribute__(( weak )) void vPortSetupTimerInterrupt( void )
 {
 	/* Calculate the constants required to configure the tick interrupt. */

cc3200/FreeRTOS/Source/tasks.c

@@ -515,6 +515,7 @@ static void prvResetNextTaskUnblockTime( void );
 
 /*-----------------------------------------------------------*/
 
+__attribute__ ((section (".boot")))
 BaseType_t xTaskGenericCreate( TaskFunction_t pxTaskCode, const char * const pcName, const uint16_t usStackDepth, void * const pvParameters, UBaseType_t uxPriority, TaskHandle_t * const pxCreatedTask, StackType_t * const puxStackBuffer, const MemoryRegion_t * const xRegions ) /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
 {
 BaseType_t xReturn;
@@ -1454,6 +1455,7 @@ TCB_t * pxNewTCB;
 #endif /* ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) ) */
 /*-----------------------------------------------------------*/
 
+__attribute__ ((section (".boot")))
 void vTaskStartScheduler( void )
 {
 BaseType_t xReturn;
@@ -2700,7 +2702,7 @@ static portTASK_FUNCTION( prvIdleTask, pvParameters )
 	}
 #endif /* configUSE_TICKLESS_IDLE */
 /*-----------------------------------------------------------*/
-
+__attribute__ ((section (".boot")))
 static void prvInitialiseTCBVariables( TCB_t * const pxTCB, const char * const pcName, UBaseType_t uxPriority, const MemoryRegion_t * const xRegions, const uint16_t usStackDepth ) /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
 {
 UBaseType_t x;
@@ -2809,7 +2811,7 @@ UBaseType_t x;
 
 #endif /* portUSING_MPU_WRAPPERS */
 /*-----------------------------------------------------------*/
-
+__attribute__ ((section (".boot")))
 static void prvInitialiseTaskLists( void )
 {
 UBaseType_t uxPriority;
@@ -2912,7 +2914,7 @@ static void prvAddCurrentTaskToDelayedList( const TickType_t xTimeToWake )
 	}
 }
 /*-----------------------------------------------------------*/
-
+__attribute__ ((section (".boot")))
 static TCB_t *prvAllocateTCBAndStack( const uint16_t usStackDepth, StackType_t * const puxStackBuffer )
 {
 TCB_t *pxNewTCB;

cc3200/application.lds

@@ -89,6 +89,17 @@ SECTIONS
         . = ALIGN(8);
         _ebss = .;
     } > SRAM
+
+    /* place here functions that are only called during boot up, */
+    /* that way, we can re-use this area for the micropython heap */
+    .boot :
+    {
+        . = ALIGN(8);
+        _boot = .;
+        *(.boot*)
+        . = ALIGN(8);
+        _eboot = .;
+    } > SRAM
      
     /* allocate the micropython heap */
     .heap :

cc3200/hal/cc3200_hal.c

@@ -78,7 +78,8 @@ extern void (* const g_pfnVectors[256])(void);
 /******************************************************************************
  DEFINE PUBLIC FUNCTIONS
  ******************************************************************************/
- 
+
+__attribute__ ((section (".boot")))
 void HAL_SystemInit (void) {
     MAP_IntVTableBaseSet((unsigned long)&g_pfnVectors[0]);
 

cc3200/hal/startup_gcc.c

@@ -60,6 +60,7 @@ extern uint32_t __init_data;
 // Forward declaration of the default fault handlers.
 //
 //*****************************************************************************
+__attribute__ ((section (".boot")))
 void ResetISR(void);
 #ifdef DEBUG
 static void NmiSR(void) __attribute__( ( naked ) );

cc3200/main.c

@@ -59,6 +59,7 @@ OsiTaskHandle   mpTaskHandle;
  DEFINE PUBLIC FUNCTIONS
  ******************************************************************************/
 
+__attribute__ ((section (".boot")))
 int main (void) {
 
     // Initialize the clocks and the interrupt system
@@ -82,7 +83,6 @@ int main (void) {
     for ( ; ; );
 }
 
-
 void stoupper (char *str) {
     while (str && *str != '\0') {
         *str = (char)toupper((int)(*str));

cc3200/mods/pybrtc.c

@@ -51,6 +51,7 @@
 ///     rtc.datetime((2014, 5, 1, 4, 13, 0, 0, 0))
 ///     print(rtc.datetime())
 
+__attribute__ ((section (".boot")))
 void pybrtc_init(void) {
     // if RTC was previously set leave it alone
     if (MAP_PRCMSysResetCauseGet() == PRCM_POWER_ON) {

cc3200/mods/pybsd.c

@@ -79,6 +79,7 @@ STATIC mp_obj_t pybsd_enable (mp_obj_t self_in);
 /******************************************************************************
  DECLARE PUBLIC FUNCTIONS
  ******************************************************************************/
+__attribute__ ((section (".boot")))
 void pybsd_init0 (void) {
     // allocate memory for the sd file system
     ASSERT ((pybsd_obj.fatfs = mem_Malloc(sizeof(FATFS))) != NULL);

cc3200/mptask.c

@@ -69,9 +69,10 @@
 /******************************************************************************
  DECLARE PRIVATE FUNCTIONS
  ******************************************************************************/
-STATIC void main_init_sflash_filesystem (void);
-STATIC void main_enter_ap_mode (void);
-STATIC void main_create_main_py (void);
+STATIC void mptask_pre_init (void);
+STATIC void mptask_init_sflash_filesystem (void);
+STATIC void mptask_enter_ap_mode (void);
+STATIC void mptask_create_main_py (void);
 
 /******************************************************************************
  DECLARE PUBLIC DATA
@@ -100,39 +101,18 @@ void TASK_Micropython (void *pvParameters) {
     bool safeboot;
     FRESULT res;
 
-#if MICROPY_HW_ENABLE_RTC
-    pybrtc_init();
-#endif
-
 #ifdef DEBUG
     safeboot = false;
 #else
     safeboot = mperror_safe_boot_requested();
 #endif
 
-    // Create the simple link spawn task
-    ASSERT (OSI_OK == VStartSimpleLinkSpawnTask(SIMPLELINK_SPAWN_TASK_PRIORITY));
-
-    // Allocate memory for the flash file system
-    ASSERT ((sflash_fatfs = mem_Malloc(sizeof(FATFS))) != NULL);
-#if MICROPY_HW_HAS_SDCARD
-    pybsd_init0();
-#endif
-
-#ifdef DEBUG
-    ASSERT (OSI_OK == osi_TaskCreate(TASK_Servers,
-                                     (const signed char *)"Servers",
-                                     SERVERS_STACK_SIZE, NULL, SERVERS_PRIORITY, &svTaskHandle));
-#else
-    ASSERT (OSI_OK == osi_TaskCreate(TASK_Servers,
-                                     (const signed char *)"Servers",
-                                     SERVERS_STACK_SIZE, NULL, SERVERS_PRIORITY, NULL));
-#endif
+    mptask_pre_init ();
 
 soft_reset:
 
     // GC init
-    gc_init(&_heap, &_eheap);
+    gc_init(&_boot, &_eheap);
 
     // Micro Python init
     mp_init();
@@ -167,13 +147,13 @@ soft_reset:
 
     mperror_enable_heartbeat();
 
-    main_enter_ap_mode();
+    mptask_enter_ap_mode();
 
     // enable telnet and ftp servers
     servers_enable();
 
     // initialize the serial flash file system
-    main_init_sflash_filesystem();
+    mptask_init_sflash_filesystem();
 
     // append the SFLASH paths to the system path
     mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_SFLASH));
@@ -268,8 +248,34 @@ soft_reset_exit:
 /******************************************************************************
  DEFINE PRIVATE FUNCTIONS
  ******************************************************************************/
+__attribute__ ((section (".boot")))
+STATIC void mptask_pre_init (void) {
+#if MICROPY_HW_ENABLE_RTC
+    pybrtc_init();
+#endif
 
-STATIC void main_init_sflash_filesystem (void) {
+    // Create the simple link spawn task
+    ASSERT (OSI_OK == VStartSimpleLinkSpawnTask(SIMPLELINK_SPAWN_TASK_PRIORITY));
+
+    // Allocate memory for the flash file system
+    ASSERT ((sflash_fatfs = mem_Malloc(sizeof(FATFS))) != NULL);
+
+#if MICROPY_HW_HAS_SDCARD
+    pybsd_init0();
+#endif
+
+#ifdef DEBUG
+    ASSERT (OSI_OK == osi_TaskCreate(TASK_Servers,
+                                     (const signed char *)"Servers",
+                                     SERVERS_STACK_SIZE, NULL, SERVERS_PRIORITY, &svTaskHandle));
+#else
+    ASSERT (OSI_OK == osi_TaskCreate(TASK_Servers,
+                                     (const signed char *)"Servers",
+                                     SERVERS_STACK_SIZE, NULL, SERVERS_PRIORITY, NULL));
+#endif
+}
+
+STATIC void mptask_init_sflash_filesystem (void) {
     // Initialise the local flash filesystem.
     // Create it if needed, and mount in on /sflash.
     // try to mount the flash
@@ -283,13 +289,13 @@ STATIC void main_init_sflash_filesystem (void) {
             __fatal_error("could not create /SFLASH file system");
         }
         // create empty main.py
-        main_create_main_py();
+        mptask_create_main_py();
     } else if (res == FR_OK) {
         // mount sucessful
         FILINFO fno;
         if (FR_OK != f_stat("/SFLASH/MAIN.PY", &fno)) {
             // create empty main.py
-            main_create_main_py();
+            mptask_create_main_py();
         }
     } else {
         __fatal_error("could not create /SFLASH file system");
@@ -321,14 +327,14 @@ STATIC void main_init_sflash_filesystem (void) {
     }
 }
 
-STATIC void main_enter_ap_mode (void) {
+STATIC void mptask_enter_ap_mode (void) {
     // Enable simplelink in low power mode
     wlan_sl_enable (ROLE_AP, SERVERS_DEF_AP_SSID, strlen(SERVERS_DEF_AP_SSID), SERVERS_DEF_AP_SECURITY,
                     SERVERS_DEF_AP_KEY, strlen(SERVERS_DEF_AP_KEY), SERVERS_DEF_AP_CHANNEL);
     wlan_set_pm_policy (SL_NORMAL_POLICY);
 }
 
-STATIC void main_create_main_py (void) {
+STATIC void mptask_create_main_py (void) {
     // create empty main.py
     FIL fp;
     f_open(&fp, "/SFLASH/MAIN.PY", FA_WRITE | FA_CREATE_ALWAYS);

cc3200/simplelink/oslib/osi_freertos.c

@@ -275,6 +275,7 @@ OsiReturnVal_e osi_LockObjCreate(OsiLockObj_t* pLockObj)
 	\note
 	\warning
 */
+__attribute__ ((section (".boot")))
 OsiReturnVal_e osi_TaskCreate(P_OSI_TASK_ENTRY pEntry,const signed char * const pcName,
                               unsigned short usStackDepth, void *pvParameters,
                               unsigned long uxPriority,OsiTaskHandle* pTaskHandle)
@@ -449,6 +450,7 @@ void vSimpleLinkSpawnTask(void *pvParameters)
 	\note
 	\warning
 */
+__attribute__ ((section (".boot")))
 OsiReturnVal_e VStartSimpleLinkSpawnTask(unsigned portBASE_TYPE uxPriority)
 {
     xSimpleLinkSpawnQueue = xQueueCreate( slQUEUE_SIZE, sizeof( tSimpleLinkSpawnMsg ) );
@@ -666,6 +668,7 @@ void osi_ExitCritical(void)
 	\note
 	\warning
 */
+__attribute__ ((section (".boot")))
 void osi_start()
 {
     vTaskStartScheduler();

cc3200/util/gccollect.h

@@ -30,6 +30,8 @@ extern uint32_t _etext;
 extern uint32_t _sidata;
 extern uint32_t _data;
 extern uint32_t _edata;
+extern uint32_t _boot;
+extern uint32_t _eboot;
 extern uint32_t _bss;
 extern uint32_t _ebss;
 extern uint32_t _heap;