/* * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #include "sdkconfig.h" #include #include #include "FreeRTOS.h" #include "task.h" //For vApplicationStackOverflowHook #include "portmacro.h" #include "spinlock.h" #include "xt_instr_macros.h" #include "xtensa/xtensa_context.h" #include "xtensa/corebits.h" #include "xtensa/config/core.h" #include "xtensa/config/core-isa.h" #include "xtensa/xtruntime.h" #include "esp_heap_caps.h" #include "esp_system.h" #include "esp_task.h" #include "esp_log.h" #include "esp_cpu.h" #include "esp_rom_sys.h" #include "esp_int_wdt.h" #include "esp_task_wdt.h" #include "esp_heap_caps_init.h" #include "esp_private/startup_internal.h" /* Required by g_spiram_ok. [refactor-todo] for g_spiram_ok */ #include "esp32/spiram.h" /* Required by esp_spiram_reserve_dma_pool() */ #ifdef CONFIG_APPTRACE_ENABLE #include "esp_app_trace.h" #endif #ifdef CONFIG_ESP_SYSTEM_GDBSTUB_RUNTIME #include "esp_gdbstub.h" /* Required by esp_gdbstub_init() */ #endif // CONFIG_ESP_SYSTEM_GDBSTUB_RUNTIME /* OS state variables */ volatile unsigned port_xSchedulerRunning[portNUM_PROCESSORS] = {0}; unsigned int port_interruptNesting[portNUM_PROCESSORS] = {0}; // Interrupt nesting level. Increased/decreased in portasm.c, _frxt_int_enter/_frxt_int_exit //FreeRTOS SMP Locks portMUX_TYPE port_xTaskLock = portMUX_INITIALIZER_UNLOCKED; portMUX_TYPE port_xISRLock = portMUX_INITIALIZER_UNLOCKED; /* ------------------------------------------------ IDF Compatibility -------------------------------------------------- * - These need to be defined for IDF to compile * ------------------------------------------------------------------------------------------------------------------ */ // --------------------- Interrupts ------------------------ BaseType_t IRAM_ATTR xPortInterruptedFromISRContext(void) { return (port_interruptNesting[xPortGetCoreID()] != 0); } // ------------------ Critical Sections -------------------- /* Variables used by IDF critical sections only (SMP tracks critical nesting inside TCB now) [refactor-todo] Figure out how IDF critical sections will be merged with SMP FreeRTOS critical sections */ BaseType_t port_uxCriticalNestingIDF[portNUM_PROCESSORS] = {0}; BaseType_t port_uxCriticalOldInterruptStateIDF[portNUM_PROCESSORS] = {0}; BaseType_t xPortEnterCriticalTimeout(portMUX_TYPE *lock, BaseType_t timeout) { /* Interrupts may already be disabled (if this function is called in nested * manner). However, there's no atomic operation that will allow us to check, * thus we have to disable interrupts again anyways. * * However, if this is call is NOT nested (i.e., the first call to enter a * critical section), we will save the previous interrupt level so that the * saved level can be restored on the last call to exit the critical. */ BaseType_t xOldInterruptLevel = XTOS_SET_INTLEVEL(XCHAL_EXCM_LEVEL); if (!spinlock_acquire(lock, timeout)) { //Timed out attempting to get spinlock. Restore previous interrupt level and return XTOS_RESTORE_JUST_INTLEVEL((int) xOldInterruptLevel); return pdFAIL; } //Spinlock acquired. Increment the IDF critical nesting count. BaseType_t coreID = xPortGetCoreID(); BaseType_t newNesting = port_uxCriticalNestingIDF[coreID] + 1; port_uxCriticalNestingIDF[coreID] = newNesting; //If this is the first entry to a critical section. Save the old interrupt level. if ( newNesting == 1 ) { port_uxCriticalOldInterruptStateIDF[coreID] = xOldInterruptLevel; } return pdPASS; } void vPortExitCriticalIDF(portMUX_TYPE *lock) { /* This function may be called in a nested manner. Therefore, we only need * to reenable interrupts if this is the last call to exit the critical. We * can use the nesting count to determine whether this is the last exit call. */ spinlock_release(lock); BaseType_t coreID = xPortGetCoreID(); BaseType_t nesting = port_uxCriticalNestingIDF[coreID]; if (nesting > 0) { nesting--; port_uxCriticalNestingIDF[coreID] = nesting; //This is the last exit call, restore the saved interrupt level if ( nesting == 0 ) { XTOS_RESTORE_JUST_INTLEVEL((int) port_uxCriticalOldInterruptStateIDF[coreID]); } } } /* In case any IDF libs called the port critical functions directly instead of through the macros. Just inline call the IDF versions */ void vPortEnterCritical(portMUX_TYPE *lock) { vPortEnterCriticalIDF(lock); } void vPortExitCritical(portMUX_TYPE *lock) { vPortExitCriticalIDF(lock); } // ----------------------- System -------------------------- #define STACK_WATCH_POINT_NUMBER (SOC_CPU_WATCHPOINTS_NUM - 1) void vPortSetStackWatchpoint( void *pxStackStart ) { //Set watchpoint 1 to watch the last 32 bytes of the stack. //Unfortunately, the Xtensa watchpoints can't set a watchpoint on a random [base - base+n] region because //the size works by masking off the lowest address bits. For that reason, we futz a bit and watch the lowest 32 //bytes of the stack we can actually watch. In general, this can cause the watchpoint to be triggered at most //28 bytes early. The value 32 is chosen because it's larger than the stack canary, which in FreeRTOS is 20 bytes. //This way, we make sure we trigger before/when the stack canary is corrupted, not after. int addr = (int)pxStackStart; addr = (addr + 31) & (~31); esp_cpu_set_watchpoint(STACK_WATCH_POINT_NUMBER, (char *)addr, 32, ESP_CPU_WATCHPOINT_STORE); } // ---------------------- Tick Timer ----------------------- extern void _frxt_tick_timer_init(void); extern void _xt_tick_divisor_init(void); /** * @brief Initialize CCONT timer to generate the tick interrupt * */ void vPortSetupTimer(void) { /* Init the tick divisor value */ _xt_tick_divisor_init(); _frxt_tick_timer_init(); } // --------------------- App Start-up ---------------------- static const char *TAG = "cpu_start"; extern void app_main(void); static void main_task(void* args) { #if !CONFIG_FREERTOS_UNICORE // Wait for FreeRTOS initialization to finish on APP CPU, before replacing its startup stack while (port_xSchedulerRunning[1] == 0) { ; } #endif // [refactor-todo] check if there is a way to move the following block to esp_system startup heap_caps_enable_nonos_stack_heaps(); // Now we have startup stack RAM available for heap, enable any DMA pool memory #if CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL if (g_spiram_ok) { esp_err_t r = esp_spiram_reserve_dma_pool(CONFIG_SPIRAM_MALLOC_RESERVE_INTERNAL); if (r != ESP_OK) { ESP_EARLY_LOGE(TAG, "Could not reserve internal/DMA pool (error 0x%x)", r); abort(); } } #endif //Initialize task wdt if configured to do so #ifdef CONFIG_ESP_TASK_WDT_PANIC ESP_ERROR_CHECK(esp_task_wdt_init(CONFIG_ESP_TASK_WDT_TIMEOUT_S, true)); #elif CONFIG_ESP_TASK_WDT ESP_ERROR_CHECK(esp_task_wdt_init(CONFIG_ESP_TASK_WDT_TIMEOUT_S, false)); #endif //Add IDLE 0 to task wdt #ifdef CONFIG_ESP_TASK_WDT_CHECK_IDLE_TASK_CPU0 TaskHandle_t idle_0 = xTaskGetIdleTaskHandleForCPU(0); if(idle_0 != NULL){ ESP_ERROR_CHECK(esp_task_wdt_add(idle_0)); } #endif //Add IDLE 1 to task wdt #ifdef CONFIG_ESP_TASK_WDT_CHECK_IDLE_TASK_CPU1 TaskHandle_t idle_1 = xTaskGetIdleTaskHandleForCPU(1); if(idle_1 != NULL){ ESP_ERROR_CHECK(esp_task_wdt_add(idle_1)); } #endif app_main(); vTaskDelete(NULL); } void esp_startup_start_app_common(void) { #if CONFIG_ESP_INT_WDT esp_int_wdt_init(); //Initialize the interrupt watch dog for CPU0. esp_int_wdt_cpu_init(); #endif esp_crosscore_int_init(); #ifdef CONFIG_ESP_SYSTEM_GDBSTUB_RUNTIME esp_gdbstub_init(); #endif // CONFIG_ESP_SYSTEM_GDBSTUB_RUNTIME TaskHandle_t main_task_hdl; portDISABLE_INTERRUPTS(); portBASE_TYPE res = xTaskCreatePinnedToCore(main_task, "main", ESP_TASK_MAIN_STACK, NULL, ESP_TASK_MAIN_PRIO, &main_task_hdl, ESP_TASK_MAIN_CORE); #if ( configUSE_CORE_AFFINITY == 1 && configNUM_CORES > 1 ) //We only need to set affinity when using dual core with affinities supported vTaskCoreAffinitySet(main_task_hdl, 1 << 1); #endif portENABLE_INTERRUPTS(); assert(res == pdTRUE); (void)res; } void esp_startup_start_app_other_cores(void) { // For now, we only support up to two core: 0 and 1. if (xPortGetCoreID() >= 2) { abort(); } // Wait for FreeRTOS initialization to finish on PRO CPU while (port_xSchedulerRunning[0] == 0) { ; } #if CONFIG_APPTRACE_ENABLE // [refactor-todo] move to esp_system initialization esp_err_t err = esp_apptrace_init(); assert(err == ESP_OK && "Failed to init apptrace module on APP CPU!"); #endif #if CONFIG_ESP_INT_WDT //Initialize the interrupt watch dog for CPU1. esp_int_wdt_cpu_init(); #endif esp_crosscore_int_init(); ESP_EARLY_LOGI(TAG, "Starting scheduler on APP CPU."); xPortStartScheduler(); abort(); /* Only get to here if FreeRTOS somehow very broken */ } void esp_startup_start_app(void) { #if !CONFIG_ESP_INT_WDT #if CONFIG_ESP32_ECO3_CACHE_LOCK_FIX assert(!soc_has_cache_lock_bug() && "ESP32 Rev 3 + Dual Core + PSRAM requires INT WDT enabled in project config!"); #endif #endif esp_startup_start_app_common(); ESP_EARLY_LOGI(TAG, "Starting scheduler on PRO CPU."); vTaskStartScheduler(); } /* ---------------------------------------------- Port Implementations ------------------------------------------------- * Implementations of Porting Interface functions * ------------------------------------------------------------------------------------------------------------------ */ // --------------------- Interrupts ------------------------ BaseType_t xPortCheckIfInISR(void) { //Disable interrupts so that reading port_interruptNesting is atomic BaseType_t ret; unsigned int prev_int_level = portDISABLE_INTERRUPTS(); ret = (port_interruptNesting[xPortGetCoreID()] != 0) ? pdTRUE : pdFALSE; portRESTORE_INTERRUPTS(prev_int_level); return ret; } // ------------------ Critical Sections -------------------- void vPortTakeLock( portMUX_TYPE *lock ) { spinlock_acquire( lock, portMUX_NO_TIMEOUT); } void vPortReleaseLock( portMUX_TYPE *lock ) { spinlock_release( lock ); } // ---------------------- Yielding ------------------------- // ----------------------- System -------------------------- /* ------------------------------------------------ FreeRTOS Portable -------------------------------------------------- * - Provides implementation for functions required by FreeRTOS * - Declared in portable.h * ------------------------------------------------------------------------------------------------------------------ */ // ----------------- Scheduler Start/End ------------------- extern void _xt_coproc_init(void); BaseType_t xPortStartScheduler( void ) { portDISABLE_INTERRUPTS(); // Interrupts are disabled at this point and stack contains PS with enabled interrupts when task context is restored #if XCHAL_CP_NUM > 0 /* Initialize co-processor management for tasks. Leave CPENABLE alone. */ _xt_coproc_init(); #endif /* Setup the hardware to generate the tick. */ vPortSetupTimer(); port_xSchedulerRunning[xPortGetCoreID()] = 1; // Cannot be directly called from C; never returns __asm__ volatile ("call0 _frxt_dispatch\n"); /* Should not get here. */ return pdTRUE; } void vPortEndScheduler( void ) { ; } // ----------------------- Memory -------------------------- #define FREERTOS_SMP_MALLOC_CAPS (MALLOC_CAP_INTERNAL|MALLOC_CAP_8BIT) void *pvPortMalloc( size_t xSize ) { return heap_caps_malloc(xSize, FREERTOS_SMP_MALLOC_CAPS); } void vPortFree( void * pv ) { heap_caps_free(pv); } void vPortInitialiseBlocks( void ) { ; //Does nothing, heap is initialized separately in ESP-IDF } size_t xPortGetFreeHeapSize( void ) { return esp_get_free_heap_size(); } #if( configSTACK_ALLOCATION_FROM_SEPARATE_HEAP == 1 ) void *pvPortMallocStack( size_t xSize ) { return NULL; } void vPortFreeStack( void *pv ) { } #endif #if ( configSUPPORT_STATIC_ALLOCATION == 1 ) void vApplicationGetIdleTaskMemory(StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize ) { StaticTask_t *pxTCBBufferTemp; StackType_t *pxStackBufferTemp; //Allocate TCB and stack buffer in internal memory pxTCBBufferTemp = pvPortMalloc(sizeof(StaticTask_t)); pxStackBufferTemp = pvPortMalloc(CONFIG_FREERTOS_IDLE_TASK_STACKSIZE); assert(pxTCBBufferTemp != NULL); assert(pxStackBufferTemp != NULL); //Write back pointers *ppxIdleTaskTCBBuffer = pxTCBBufferTemp; *ppxIdleTaskStackBuffer = pxStackBufferTemp; *pulIdleTaskStackSize = CONFIG_FREERTOS_IDLE_TASK_STACKSIZE; } void vApplicationGetTimerTaskMemory(StaticTask_t **ppxTimerTaskTCBBuffer, StackType_t **ppxTimerTaskStackBuffer, uint32_t *pulTimerTaskStackSize ) { StaticTask_t *pxTCBBufferTemp; StackType_t *pxStackBufferTemp; //Allocate TCB and stack buffer in internal memory pxTCBBufferTemp = pvPortMalloc(sizeof(StaticTask_t)); pxStackBufferTemp = pvPortMalloc(configTIMER_TASK_STACK_DEPTH); assert(pxTCBBufferTemp != NULL); assert(pxStackBufferTemp != NULL); //Write back pointers *ppxTimerTaskTCBBuffer = pxTCBBufferTemp; *ppxTimerTaskStackBuffer = pxStackBufferTemp; *pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH; } #endif //( configSUPPORT_STATIC_ALLOCATION == 1 ) // ------------------------ Stack -------------------------- // User exception dispatcher when exiting void _xt_user_exit(void); #if CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER // Wrapper to allow task functions to return (increases stack overhead by 16 bytes) static void vPortTaskWrapper(TaskFunction_t pxCode, void *pvParameters) { pxCode(pvParameters); //FreeRTOS tasks should not return. Log the task name and abort. char *pcTaskName = pcTaskGetName(NULL); ESP_LOGE("FreeRTOS", "FreeRTOS Task \"%s\" should not return, Aborting now!", pcTaskName); abort(); } #endif #if ( portHAS_STACK_OVERFLOW_CHECKING == 1 ) StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack, StackType_t * pxEndOfStack, TaskFunction_t pxCode, void * pvParameters, BaseType_t xRunPrivileged ) #else StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack, TaskFunction_t pxCode, void * pvParameters, BaseType_t xRunPrivileged ) #endif { StackType_t *sp, *tp; XtExcFrame *frame; #if XCHAL_CP_NUM > 0 uint32_t *p; #endif uint32_t *threadptr; void *task_thread_local_start; extern int _thread_local_start, _thread_local_end, _flash_rodata_start, _flash_rodata_align; // TODO: check that TLS area fits the stack uint32_t thread_local_sz = (uint8_t *)&_thread_local_end - (uint8_t *)&_thread_local_start; thread_local_sz = ALIGNUP(0x10, thread_local_sz); /* Initialize task's stack so that we have the following structure at the top: ----LOW ADDRESSES ----------------------------------------HIGH ADDRESSES---------- task stack | interrupt stack frame | thread local vars | co-processor save area | ---------------------------------------------------------------------------------- | | SP pxTopOfStack All parts are aligned to 16 byte boundary. */ sp = (StackType_t *) (((UBaseType_t)pxTopOfStack - XT_CP_SIZE - thread_local_sz - XT_STK_FRMSZ) & ~0xf); /* Clear the entire frame (do not use memset() because we don't depend on C library) */ for (tp = sp; tp <= pxTopOfStack; ++tp) { *tp = 0; } frame = (XtExcFrame *) sp; /* Explicitly initialize certain saved registers */ #if CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER frame->pc = (UBaseType_t) vPortTaskWrapper; /* task wrapper */ #else frame->pc = (UBaseType_t) pxCode; /* task entrypoint */ #endif frame->a0 = 0; /* to terminate GDB backtrace */ frame->a1 = (UBaseType_t) sp + XT_STK_FRMSZ; /* physical top of stack frame */ frame->exit = (UBaseType_t) _xt_user_exit; /* user exception exit dispatcher */ /* Set initial PS to int level 0, EXCM disabled ('rfe' will enable), user mode. */ /* Also set entry point argument parameter. */ #ifdef __XTENSA_CALL0_ABI__ #if CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER frame->a2 = (UBaseType_t) pxCode; frame->a3 = (UBaseType_t) pvParameters; #else frame->a2 = (UBaseType_t) pvParameters; #endif frame->ps = PS_UM | PS_EXCM; #else /* __XTENSA_CALL0_ABI__ */ /* + for windowed ABI also set WOE and CALLINC (pretend task was 'call4'd). */ #if CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER frame->a6 = (UBaseType_t) pxCode; frame->a7 = (UBaseType_t) pvParameters; #else frame->a6 = (UBaseType_t) pvParameters; #endif frame->ps = PS_UM | PS_EXCM | PS_WOE | PS_CALLINC(1); #endif /* __XTENSA_CALL0_ABI__ */ #ifdef XT_USE_SWPRI /* Set the initial virtual priority mask value to all 1's. */ frame->vpri = 0xFFFFFFFF; #endif /* Init threadptr register and set up TLS run-time area. * The diagram in port/riscv/port.c illustrates the calculations below. */ task_thread_local_start = (void *)(((uint32_t)pxTopOfStack - XT_CP_SIZE - thread_local_sz) & ~0xf); memcpy(task_thread_local_start, &_thread_local_start, thread_local_sz); threadptr = (uint32_t *)(sp + XT_STK_EXTRA); /* Calculate THREADPTR value. * The generated code will add THREADPTR value to a constant value determined at link time, * to get the address of the TLS variable. * The constant value is calculated by the linker as follows * (search for 'tpoff' in elf32-xtensa.c in BFD): * offset = address - tls_section_vma + align_up(TCB_SIZE, tls_section_alignment) * where TCB_SIZE is hardcoded to 8. * Note this is slightly different compared to the RISC-V port, where offset = address - tls_section_vma. */ const uint32_t tls_section_alignment = (uint32_t) &_flash_rodata_align; /* ALIGN value of .flash.rodata section */ const uint32_t tcb_size = 8; /* Unrelated to FreeRTOS, this is the constant from BFD */ const uint32_t base = (tcb_size + tls_section_alignment - 1) & (~(tls_section_alignment - 1)); *threadptr = (uint32_t)task_thread_local_start - ((uint32_t)&_thread_local_start - (uint32_t)&_flash_rodata_start) - base; #if XCHAL_CP_NUM > 0 /* Init the coprocessor save area (see xtensa_context.h) */ /* No access to TCB here, so derive indirectly. Stack growth is top to bottom. * //p = (uint32_t *) xMPUSettings->coproc_area; */ p = (uint32_t *)(((uint32_t) pxTopOfStack - XT_CP_SIZE) & ~0xf); configASSERT( ( uint32_t ) p >= frame->a1 ); p[0] = 0; p[1] = 0; p[2] = (((uint32_t) p) + 12 + XCHAL_TOTAL_SA_ALIGN - 1) & -XCHAL_TOTAL_SA_ALIGN; #endif /* XCHAL_CP_NUM */ return sp; } // -------------------- Tick Handler ----------------------- extern void esp_vApplicationIdleHook(void); extern void esp_vApplicationTickHook(void); BaseType_t xPortSysTickHandler(void) { portbenchmarkIntLatency(); traceISR_ENTER(SYSTICK_INTR_ID); BaseType_t ret; if (portGET_CORE_ID() == 0) { //Only Core 0 calls xTaskIncrementTick(); ret = xTaskIncrementTick(); } else { //Manually call the IDF tick hooks esp_vApplicationTickHook(); ret = pdFALSE; } if(ret != pdFALSE) { portYIELD_FROM_ISR(); } else { traceISR_EXIT(); } return ret; } // ------------------- Hook Functions ---------------------- #include #if ( configCHECK_FOR_STACK_OVERFLOW > 0 ) void __attribute__((weak)) vApplicationStackOverflowHook( TaskHandle_t xTask, char *pcTaskName ) { #define ERR_STR1 "***ERROR*** A stack overflow in task " #define ERR_STR2 " has been detected." const char *str[] = {ERR_STR1, pcTaskName, ERR_STR2}; char buf[sizeof(ERR_STR1) + CONFIG_FREERTOS_MAX_TASK_NAME_LEN + sizeof(ERR_STR2) + 1 /* null char */] = { 0 }; char *dest = buf; for (size_t i = 0 ; i < sizeof(str) / sizeof(str[0]); i++) { dest = strcat(dest, str[i]); } esp_system_abort(buf); } #endif #if ( configUSE_TICK_HOOK > 0 ) void vApplicationTickHook( void ) { esp_vApplicationTickHook(); } #endif #if CONFIG_FREERTOS_USE_MINIMAL_IDLE_HOOK /* By default, the port uses vApplicationMinimalIdleHook() to run IDF style idle hooks. However, users may also want to provide their own vApplicationMinimalIdleHook(). In this case, we use to -Wl,--wrap option to wrap the user provided vApplicationMinimalIdleHook() */ extern void __real_vApplicationMinimalIdleHook( void ); void __wrap_vApplicationMinimalIdleHook( void ) { esp_vApplicationIdleHook(); //Run IDF style hooks __real_vApplicationMinimalIdleHook(); //Call the user provided vApplicationMinimalIdleHook() } #else // CONFIG_FREERTOS_USE_MINIMAL_IDLE_HOOK void vApplicationMinimalIdleHook( void ) { esp_vApplicationIdleHook(); //Run IDF style hooks } #endif // CONFIG_FREERTOS_USE_MINIMAL_IDLE_HOOK /* ---------------------------------------------- Misc Implementations ------------------------------------------------- * * ------------------------------------------------------------------------------------------------------------------ */ // -------------------- Co-Processor ----------------------- /* * Used to set coprocessor area in stack. Current hack is to reuse MPU pointer for coprocessor area. */ #if portUSING_MPU_WRAPPERS void vPortStoreTaskMPUSettings( xMPU_SETTINGS *xMPUSettings, const struct xMEMORY_REGION *const xRegions, StackType_t *pxBottomOfStack, uint32_t usStackDepth ) { #if XCHAL_CP_NUM > 0 xMPUSettings->coproc_area = ( StackType_t * ) ( ( uint32_t ) ( pxBottomOfStack + usStackDepth - 1 )); xMPUSettings->coproc_area = ( StackType_t * ) ( ( ( portPOINTER_SIZE_TYPE ) xMPUSettings->coproc_area ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) ); xMPUSettings->coproc_area = ( StackType_t * ) ( ( ( uint32_t ) xMPUSettings->coproc_area - XT_CP_SIZE ) & ~0xf ); /* NOTE: we cannot initialize the coprocessor save area here because FreeRTOS is going to * clear the stack area after we return. This is done in pxPortInitialiseStack(). */ #endif } void vPortReleaseTaskMPUSettings( xMPU_SETTINGS *xMPUSettings ) { /* If task has live floating point registers somewhere, release them */ _xt_coproc_release( xMPUSettings->coproc_area ); } #endif /* portUSING_MPU_WRAPPERS */