mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-04-19 21:11:57 -04:00
146 lines
4.7 KiB
C
146 lines
4.7 KiB
C
/*
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* FreeRTOS Kernel <DEVELOPMENT BRANCH>
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* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* https://www.FreeRTOS.org
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* https://github.com/FreeRTOS
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*
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* 1 tab == 4 spaces!
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*/
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/* Standard includes. */
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#include <stdlib.h>
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/* Kernel includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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/* Machine includes */
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#include <machine/counter.h>
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#include <machine/ic.h>
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/*-----------------------------------------------------------*/
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/* The initial PSR has the Previous Interrupt Enabled (PIEN) flag set. */
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#define portINITIAL_PSR ( 0x00020000 )
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/*-----------------------------------------------------------*/
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/*
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* Perform any hardware configuration necessary to generate the tick interrupt.
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*/
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static void prvSetupTimerInterrupt( void );
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/*-----------------------------------------------------------*/
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StackType_t *pxPortInitialiseStack( StackType_t * pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
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{
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/* Make space on the stack for the context - this leaves a couple of spaces
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empty. */
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pxTopOfStack -= 20;
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/* Fill the registers with known values to assist debugging. */
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pxTopOfStack[ 16 ] = 0;
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pxTopOfStack[ 15 ] = portINITIAL_PSR;
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pxTopOfStack[ 14 ] = ( uint32_t ) pxCode;
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pxTopOfStack[ 13 ] = 0x00000000UL; /* R15. */
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pxTopOfStack[ 12 ] = 0x00000000UL; /* R14. */
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pxTopOfStack[ 11 ] = 0x0d0d0d0dUL;
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pxTopOfStack[ 10 ] = 0x0c0c0c0cUL;
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pxTopOfStack[ 9 ] = 0x0b0b0b0bUL;
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pxTopOfStack[ 8 ] = 0x0a0a0a0aUL;
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pxTopOfStack[ 7 ] = 0x09090909UL;
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pxTopOfStack[ 6 ] = 0x08080808UL;
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pxTopOfStack[ 5 ] = 0x07070707UL;
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pxTopOfStack[ 4 ] = 0x06060606UL;
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pxTopOfStack[ 3 ] = 0x05050505UL;
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pxTopOfStack[ 2 ] = 0x04040404UL;
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pxTopOfStack[ 1 ] = 0x03030303UL;
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pxTopOfStack[ 0 ] = ( uint32_t ) pvParameters;
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return pxTopOfStack;
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}
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/*-----------------------------------------------------------*/
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BaseType_t xPortStartScheduler( void )
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{
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/* Set-up the timer interrupt. */
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prvSetupTimerInterrupt();
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/* Integrated Interrupt Controller: Enable all interrupts. */
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ic->ien = 1;
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/* Restore callee saved registers. */
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portRESTORE_CONTEXT();
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/* Should not get here. */
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return 0;
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}
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/*-----------------------------------------------------------*/
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static void prvSetupTimerInterrupt( void )
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{
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/* Enable timer interrupts */
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counter1->reload = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1;
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counter1->value = counter1->reload;
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counter1->mask = 1;
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/* Set the IRQ Handler priority and enable it. */
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irq[ IRQ_COUNTER1 ].ien = 1;
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}
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/*-----------------------------------------------------------*/
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/* Trap 31 handler. */
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void interrupt31_handler( void ) __attribute__((naked));
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void interrupt31_handler( void )
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{
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portSAVE_CONTEXT();
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__asm volatile ( "call vTaskSwitchContext" );
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portRESTORE_CONTEXT();
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}
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/*-----------------------------------------------------------*/
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static void prvProcessTick( void ) __attribute__((noinline));
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static void prvProcessTick( void )
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{
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if( xTaskIncrementTick() != pdFALSE )
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{
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vTaskSwitchContext();
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}
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/* Clear the Tick Interrupt. */
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counter1->expired = 0;
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}
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/*-----------------------------------------------------------*/
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/* Timer 1 interrupt handler, used for tick interrupt. */
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void interrupt7_handler( void ) __attribute__((naked));
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void interrupt7_handler( void )
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{
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portSAVE_CONTEXT();
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prvProcessTick();
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portRESTORE_CONTEXT();
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}
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/*-----------------------------------------------------------*/
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void vPortEndScheduler( void )
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{
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/* Nothing to do. Unlikely to want to end. */
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}
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/*-----------------------------------------------------------*/
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