text: /*
   * FreeRTOS V202107.00
   * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy of
   * this software and associated documentation files (the "Software"), to deal in
   * the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
   * the Software, and to permit persons to whom the Software is furnished to do so,
   * subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
   * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
   * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
   * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   * http://www.FreeRTOS.org
   * http://aws.amazon.com/freertos
   *
   * 1 tab == 4 spaces!
   */
  
  /******************************************************************************
   * This project provides two demo applications.  A simple blinky style project,
   * and a more comprehensive test and demo application.  The
   * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting (defined in this file) is used to
   * select between the two.  The simply blinky demo is implemented and described
   * in main_blinky.c.  The more comprehensive test and demo application is
   * implemented and described in main_full.c.
   *
   * This file implements the code that is not demo specific, including the
   * hardware setup and FreeRTOS hook functions.  It also contains a dummy
   * interrupt service routine called Dummy_IRQHandler() that is provided as an
   * example of how to use interrupt safe FreeRTOS API functions (those that end
   * in "FromISR").
   *
   *****************************************************************************/
  
  /* Standard includes. */
  #include "string.h"
  
  /* FreeRTOS includes. */
  #include "FreeRTOS.h"
  #include "task.h"
  
  /* Hardware specific includes. */
  #include "lpc11xx.h"
  
  /* Set mainCREATE_SIMPLE_BLINKY_DEMO_ONLY to one to run the simple blinky demo,
  or 0 to run the more comprehensive test and demo application. */
  #define mainCREATE_SIMPLE_BLINKY_DEMO_ONLY	0
  
  /* The bit on port 0 to which the LED is wired. */
  #define mainLED_BIT		( 1UL << 7UL )
  
  /* The configCHECK_FOR_STACK_OVERFLOW setting in FreeRTOSConifg can be used to
  check task stacks for overflows.  It does not however check the stack used by
  interrupts.  This demo has a simple addition that will also check the stack used
  by interrupts if mainCHECK_INTERRUPT_STACK is set to 1.  Note that this check is
  only performed from the tick hook function (which runs in an interrupt context).
  It is a good debugging aid - but won't catch interrupt stack problems until the
  tick interrupt next executes. */
  #define mainCHECK_INTERRUPT_STACK			1
  #if mainCHECK_INTERRUPT_STACK == 1
  	const unsigned char ucExpectedInterruptStackValues[] = { 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC };
  #endif
  
  /*-----------------------------------------------------------*/
  
  /*
   * Perform any application specific hardware configuration.  The clocks,
   * memory, etc. are configured before main() is called.
   */
  static void prvSetupHardware( void );
  
  /*
   * The hardware only has a single LED.  Simply toggle it.
   */
  void vMainToggleLED( void );
  
  /* main_blinky() is used when mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is set to 1.
  main_full() is used when mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is set to 0. */
  void main_blinky( void );
  void main_full( void );
  
  /*-----------------------------------------------------------*/
  
  /* The GPIO port to which the LED is attached. */
  static LPC_GPIO_TypeDef * const xGPIO0 = LPC_GPIO0;
  
  /*-----------------------------------------------------------*/
  int main( void )
  {
  	/* Prepare the hardware to run this demo. */
  	prvSetupHardware();
  
  	/* The mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting is described at the top
  	of this file. */
  	#if mainCREATE_SIMPLE_BLINKY_DEMO_ONLY == 1
  	{
  		main_blinky();
  	}
  	#else
  	{
  		main_full();
  	}
  	#endif
  
  	return 0;
  }
  /*-----------------------------------------------------------*/
  
  void vMainToggleLED( void )
  {
  static unsigned long ulLEDState = 0UL;
  
  	if( ulLEDState == 0UL )
  	{
  		xGPIO0->MASKED_ACCESS[ mainLED_BIT ] = 0UL;
  	}
  	else
  	{
  		xGPIO0->MASKED_ACCESS[ mainLED_BIT ] = mainLED_BIT;
  	}
  
  	ulLEDState = !ulLEDState;
  }
  /*-----------------------------------------------------------*/
  
  static void prvSetupHardware( void )
  {
  extern unsigned long _vStackTop[], _pvHeapStart[];
  unsigned long ulInterruptStackSize;
  
  	/* Enable AHB clock for GPIO. */
  	LPC_SYSCON->SYSAHBCLKCTRL |= ( 1 << 6 );
  
  	/* Configure GPIO for LED output. */
  	xGPIO0->DIR |= mainLED_BIT;
  
  	/* The size of the stack used by main and interrupts is not defined in
  	the linker, but just uses whatever RAM is left.  Calculate the amount of
  	RAM available for the main/interrupt/system stack, and check it against
  	a reasonable number.  If this assert is hit then it is likely you don't
  	have enough stack to start the kernel, or to allow interrupts to nest.
  	Note - this is separate to the stacks that are used by tasks.  The stacks
  	that are used by tasks are automatically checked if
  	configCHECK_FOR_STACK_OVERFLOW is not 0 in FreeRTOSConfig.h - but the stack
  	used by interrupts is not.  Reducing the conifgTOTAL_HEAP_SIZE setting will
  	increase the stack available to main() and interrupts. */
  	ulInterruptStackSize = ( ( unsigned long ) _vStackTop ) - ( ( unsigned long ) _pvHeapStart );
  	configASSERT( ulInterruptStackSize > 350UL );
  
  	/* Fill the stack used by main() and interrupts to a known value, so its
  	use can be manually checked. */
  	memcpy( ( void * ) _pvHeapStart, ucExpectedInterruptStackValues, sizeof( ucExpectedInterruptStackValues ) );
  }
  /*-----------------------------------------------------------*/
  
  void vApplicationMallocFailedHook( void )
  {
  	/* vApplicationMallocFailedHook() will only be called if
  	configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h.  It is a hook
  	function that will get called if a call to pvPortMalloc() fails.
  	pvPortMalloc() is called internally by the kernel whenever a task, queue,
  	timer or semaphore is created.  It is also called by various parts of the
  	demo application.  If heap_1.c or heap_2.c are used, then the size of the
  	heap available to pvPortMalloc() is defined by configTOTAL_HEAP_SIZE in
  	FreeRTOSConfig.h, and the xPortGetFreeHeapSize() API function can be used
  	to query the size of free heap space that remains (although it does not
  	provide information on how the remaining heap might be fragmented). */
  	taskDISABLE_INTERRUPTS();
  	for( ;; );
  }
  /*-----------------------------------------------------------*/
  
  void vApplicationIdleHook( void )
  {
  	/* vApplicationIdleHook() will only be called if configUSE_IDLE_HOOK is set
  	to 1 in FreeRTOSConfig.h.  It will be called on each iteration of the idle
  	task.  It is essential that code added to this hook function never attempts
  	to block in any way (for example, call xQueueReceive() with a block time
  	specified, or call vTaskDelay()).  If the application makes use of the
  	vTaskDelete() API function (as this demo application does) then it is also
  	important that vApplicationIdleHook() is permitted to return to its calling
  	function, because it is the responsibility of the idle task to clean up
  	memory allocated by the kernel to any task that has since been deleted. */
  }
  /*-----------------------------------------------------------*/
  
  void vApplicationStackOverflowHook( TaskHandle_t pxTask, char *pcTaskName )
  {
  	( void ) pcTaskName;
  	( void ) pxTask;
  
  	/* Run time stack overflow checking is performed if
  	configCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2.  This hook
  	function is called if a stack overflow is detected. */
  	taskDISABLE_INTERRUPTS();
  	for( ;; );
  }
  /*-----------------------------------------------------------*/
  
  void vApplicationTickHook( void )
  {
  #if mainCHECK_INTERRUPT_STACK == 1
  extern unsigned long _pvHeapStart[];
  
  	/* This function will be called by each tick interrupt if
  	configUSE_TICK_HOOK is set to 1 in FreeRTOSConfig.h.  User code can be
  	added here, but the tick hook is called from an interrupt context, so
  	code must not attempt to block, and only the interrupt safe FreeRTOS API
  	functions can be used (those that end in FromISR()). */
  
  	/* Manually check the last few bytes of the interrupt stack to check they
  	have not been overwritten.  Note - the task stacks are automatically
  	checked for overflow if configCHECK_FOR_STACK_OVERFLOW is set to 1 or 2
  	in FreeRTOSConifg.h, but the interrupt stack is not. */
  	configASSERT( memcmp( ( void * ) _pvHeapStart, ucExpectedInterruptStackValues, sizeof( ucExpectedInterruptStackValues ) ) == 0U );
  #endif /* mainCHECK_INTERRUPT_STACK */
  }
  /*-----------------------------------------------------------*/
  
  #ifdef JUST_AN_EXAMPLE_ISR
  
  void Dummy_IRQHandler(void)
  {
  long lHigherPriorityTaskWoken = pdFALSE;
  
  	/* Clear the interrupt if necessary. */
  	Dummy_ClearITPendingBit();
  
  	/* This interrupt does nothing more than demonstrate how to synchronise a
  	task with an interrupt.  A semaphore is used for this purpose.  Note
  	lHigherPriorityTaskWoken is initialised to zero.  Only FreeRTOS API functions
  	that end in "FromISR" can be called from an ISR. */
  	xSemaphoreGiveFromISR( xTestSemaphore, &lHigherPriorityTaskWoken );
  
  	/* If there was a task that was blocked on the semaphore, and giving the
  	semaphore caused the task to unblock, and the unblocked task has a priority
  	higher than the current Running state task (the task that this interrupt
  	interrupted), then lHigherPriorityTaskWoken will have been set to pdTRUE
  	internally within xSemaphoreGiveFromISR().  Passing pdTRUE into the
  	portEND_SWITCHING_ISR() macro will result in a context switch being pended to
  	ensure this interrupt returns directly to the unblocked, higher priority,
  	task.  Passing pdFALSE into portEND_SWITCHING_ISR() has no effect. */
  	portEND_SWITCHING_ISR( lHigherPriorityTaskWoken );
  }
  
  #endif /* JUST_AN_EXAMPLE_ISR */
  
  
  
  
  