text: /*
   * FreeRTOS Kernel V10.4.5
   * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
   *
   * SPDX-License-Identifier: MIT
   *
   * 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.
   *
   * https://www.FreeRTOS.org
   * https://github.com/FreeRTOS
   *
   */
  
  /*-----------------------------------------------------------
   * Implementation of functions defined in portable.h for the PPC405 port.
   *----------------------------------------------------------*/
  
  
  /* Scheduler includes. */
  #include "FreeRTOS.h"
  #include "task.h"
  
  /* Library includes. */
  #include "xtime_l.h"
  #include "xintc.h"
  #include "xintc_i.h"
  
  /*-----------------------------------------------------------*/
  
  /* Definitions to set the initial MSR of each task. */
  #define portCRITICAL_INTERRUPT_ENABLE	( 1UL << 17UL )
  #define portEXTERNAL_INTERRUPT_ENABLE	( 1UL << 15UL )
  #define portMACHINE_CHECK_ENABLE		( 1UL << 12UL )
  
  #if configUSE_FPU == 1
  	#define portAPU_PRESENT				( 1UL << 25UL )
  	#define portFCM_FPU_PRESENT			( 1UL << 13UL )
  #else
  	#define portAPU_PRESENT				( 0UL )
  	#define portFCM_FPU_PRESENT			( 0UL )
  #endif
  
  #define portINITIAL_MSR		( portCRITICAL_INTERRUPT_ENABLE | portEXTERNAL_INTERRUPT_ENABLE | portMACHINE_CHECK_ENABLE | portAPU_PRESENT | portFCM_FPU_PRESENT )
  
  
  extern const unsigned _SDA_BASE_;
  extern const unsigned _SDA2_BASE_;
  
  /*-----------------------------------------------------------*/
  
  /*
   * Setup the system timer to generate the tick interrupt.
   */
  static void prvSetupTimerInterrupt( void );
  
  /*
   * The handler for the tick interrupt - defined in portasm.s.
   */
  extern void vPortTickISR( void );
  
  /*
   * The handler for the yield function - defined in portasm.s.
   */
  extern void vPortYield( void );
  
  /*
   * Function to start the scheduler running by starting the highest
   * priority task that has thus far been created.
   */
  extern void vPortStartFirstTask( void );
  
  /*-----------------------------------------------------------*/
  
  /* Structure used to hold the state of the interrupt controller. */
  static XIntc xInterruptController;
  
  /*-----------------------------------------------------------*/
  
  /* 
   * Initialise the stack of a task to look exactly as if the task had been
   * interrupted.
   * 
   * See the header file portable.h.
   */
  StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
  {
  	/* Place a known value at the bottom of the stack for debugging. */
  	*pxTopOfStack = 0xDEADBEEF;
  	pxTopOfStack--;
  
  	/* EABI stack frame. */
  	pxTopOfStack -= 20;	/* Previous backchain and LR, R31 to R4 inclusive. */
  
  	/* Parameters in R13. */
  	*pxTopOfStack = ( StackType_t ) &_SDA_BASE_; /* address of the first small data area */
  	pxTopOfStack -= 10;
  
  	/* Parameters in R3. */
  	*pxTopOfStack = ( StackType_t ) pvParameters;
  	pxTopOfStack--;
  
  	/* Parameters in R2. */
  	*pxTopOfStack = ( StackType_t ) &_SDA2_BASE_;	/* address of the second small data area */
  	pxTopOfStack--;
  
  	/* R1 is the stack pointer so is omitted. */
  
  	*pxTopOfStack = 0x10000001UL;;	/* R0. */
  	pxTopOfStack--;
  	*pxTopOfStack = 0x00000000UL;	/* USPRG0. */
  	pxTopOfStack--;
  	*pxTopOfStack = 0x00000000UL;	/* CR. */
  	pxTopOfStack--;
  	*pxTopOfStack = 0x00000000UL;	/* XER. */
  	pxTopOfStack--;
  	*pxTopOfStack = 0x00000000UL;	/* CTR. */
  	pxTopOfStack--;
  	*pxTopOfStack = ( StackType_t ) vPortEndScheduler;	/* LR. */
  	pxTopOfStack--;
  	*pxTopOfStack = ( StackType_t ) pxCode; /* SRR0. */
  	pxTopOfStack--;
  	*pxTopOfStack = portINITIAL_MSR;/* SRR1. */
  	pxTopOfStack--;
  	*pxTopOfStack = ( StackType_t ) vPortEndScheduler;/* Next LR. */
  	pxTopOfStack--;
  	*pxTopOfStack = 0x00000000UL;/* Backchain. */
  
  	return pxTopOfStack;
  }
  /*-----------------------------------------------------------*/
  
  BaseType_t xPortStartScheduler( void )
  {
  	prvSetupTimerInterrupt();
  	XExc_RegisterHandler( XEXC_ID_SYSTEM_CALL, ( XExceptionHandler ) vPortYield, ( void * ) 0 );
  	vPortStartFirstTask();
  
  	/* Should not get here as the tasks are now running! */
  	return pdFALSE;
  }
  /*-----------------------------------------------------------*/
  
  void vPortEndScheduler( void )
  {
  	/* Not implemented. */
  	for( ;; );
  }
  /*-----------------------------------------------------------*/
  
  /*
   * Hardware initialisation to generate the RTOS tick.   
   */
  static void prvSetupTimerInterrupt( void )
  {
  const uint32_t ulInterval = ( ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );
  
  	XTime_PITClearInterrupt();
  	XTime_FITClearInterrupt();
  	XTime_WDTClearInterrupt();
  	XTime_WDTDisableInterrupt();
  	XTime_FITDisableInterrupt();
  
  	XExc_RegisterHandler( XEXC_ID_PIT_INT, ( XExceptionHandler ) vPortTickISR, ( void * ) 0 );
  
  	XTime_PITEnableAutoReload();
  	XTime_PITSetInterval( ulInterval );
  	XTime_PITEnableInterrupt();
  }
  /*-----------------------------------------------------------*/
  
  void vPortISRHandler( void *pvNullDoNotUse )
  {
  uint32_t ulInterruptStatus, ulInterruptMask = 1UL;
  BaseType_t xInterruptNumber;
  XIntc_Config *pxInterruptController;
  XIntc_VectorTableEntry *pxTable;
  
  	/* Just to remove compiler warning. */
  	( void ) pvNullDoNotUse;	
  
  	/* Get the configuration by using the device ID - in this case it is
  	assumed that only one interrupt controller is being used. */
  	pxInterruptController = &XIntc_ConfigTable[ XPAR_XPS_INTC_0_DEVICE_ID ];
    
  	/* Which interrupts are pending? */
  	ulInterruptStatus = XIntc_mGetIntrStatus( pxInterruptController->BaseAddress );
    
  	for( xInterruptNumber = 0; xInterruptNumber < XPAR_INTC_MAX_NUM_INTR_INPUTS; xInterruptNumber++ )
  	{
  		if( ulInterruptStatus & 0x01UL )
  		{
  			/* Clear the pending interrupt. */
  			XIntc_mAckIntr( pxInterruptController->BaseAddress, ulInterruptMask );
  
  			/* Call the registered handler. */
  			pxTable = &( pxInterruptController->HandlerTable[ xInterruptNumber ] );
  			pxTable->Handler( pxTable->CallBackRef );
  		}
          
  		/* Check the next interrupt. */
  		ulInterruptMask <<= 0x01UL;
  		ulInterruptStatus >>= 0x01UL;
  
  		/* Have we serviced all interrupts? */
  		if( ulInterruptStatus == 0UL )
  		{
  			break;
  		}
  	}
  }
  /*-----------------------------------------------------------*/
  
  void vPortSetupInterruptController( void )
  {
  extern void vPortISRWrapper( void );
  
  	/* Perform all library calls necessary to initialise the exception table
  	and interrupt controller.  This assumes only one interrupt controller is in
  	use. */
  	XExc_mDisableExceptions( XEXC_NON_CRITICAL );
  	XExc_Init();
  
  	/* The library functions save the context - we then jump to a wrapper to
  	save the stack into the TCB.  The wrapper then calls the handler defined
  	above. */
  	XExc_RegisterHandler( XEXC_ID_NON_CRITICAL_INT, ( XExceptionHandler ) vPortISRWrapper, NULL );
  	XIntc_Initialize( &xInterruptController, XPAR_XPS_INTC_0_DEVICE_ID );
  	XIntc_Start( &xInterruptController, XIN_REAL_MODE );
  }
  /*-----------------------------------------------------------*/
  
  BaseType_t xPortInstallInterruptHandler( uint8_t ucInterruptID, XInterruptHandler pxHandler, void *pvCallBackRef )
  {
  BaseType_t xReturn = pdFAIL;
  
  	/* This function is defined here so the scope of xInterruptController can
  	remain within this file. */
  
  	if( XST_SUCCESS == XIntc_Connect( &xInterruptController, ucInterruptID, pxHandler, pvCallBackRef ) )
  	{
  		XIntc_Enable( &xInterruptController, ucInterruptID );
  		xReturn = pdPASS;
  	}
  
  	return xReturn;		
  }
  