/* | |
FreeRTOS V8.2.1 - Copyright (C) 2015 Real Time Engineers Ltd. | |
All rights reserved | |
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
This file is part of the FreeRTOS distribution. | |
FreeRTOS is free software; you can redistribute it and/or modify it under | |
the terms of the GNU General Public License (version 2) as published by the | |
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception. | |
*************************************************************************** | |
>>! NOTE: The modification to the GPL is included to allow you to !<< | |
>>! distribute a combined work that includes FreeRTOS without being !<< | |
>>! obliged to provide the source code for proprietary components !<< | |
>>! outside of the FreeRTOS kernel. !<< | |
*************************************************************************** | |
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY | |
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
FOR A PARTICULAR PURPOSE. Full license text is available on the following | |
link: http://www.freertos.org/a00114.html | |
*************************************************************************** | |
* * | |
* FreeRTOS provides completely free yet professionally developed, * | |
* robust, strictly quality controlled, supported, and cross * | |
* platform software that is more than just the market leader, it * | |
* is the industry's de facto standard. * | |
* * | |
* Help yourself get started quickly while simultaneously helping * | |
* to support the FreeRTOS project by purchasing a FreeRTOS * | |
* tutorial book, reference manual, or both: * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
*************************************************************************** | |
http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading | |
the FAQ page "My application does not run, what could be wrong?". Have you | |
defined configASSERT()? | |
http://www.FreeRTOS.org/support - In return for receiving this top quality | |
embedded software for free we request you assist our global community by | |
participating in the support forum. | |
http://www.FreeRTOS.org/training - Investing in training allows your team to | |
be as productive as possible as early as possible. Now you can receive | |
FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers | |
Ltd, and the world's leading authority on the world's leading RTOS. | |
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
including FreeRTOS+Trace - an indispensable productivity tool, a DOS | |
compatible FAT file system, and our tiny thread aware UDP/IP stack. | |
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Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. | |
http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High | |
Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS | |
licenses offer ticketed support, indemnification and commercial middleware. | |
http://www.SafeRTOS.com - High Integrity Systems also provide a safety | |
engineered and independently SIL3 certified version for use in safety and | |
mission critical applications that require provable dependability. | |
1 tab == 4 spaces! | |
*/ | |
/*----------------------------------------------------------- | |
* Implementation of functions defined in portable.h for the ARM CM4F port. | |
*----------------------------------------------------------*/ | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
/* Constants required to manipulate the NVIC. */ | |
#define portNVIC_SYSTICK_CTRL ( ( volatile uint32_t * ) 0xe000e010 ) | |
#define portNVIC_SYSTICK_LOAD ( ( volatile uint32_t * ) 0xe000e014 ) | |
#define portNVIC_SYSPRI2 ( ( volatile uint32_t * ) 0xe000ed20 ) | |
#define portNVIC_SYSTICK_CLK 0x00000004 | |
#define portNVIC_SYSTICK_INT 0x00000002 | |
#define portNVIC_SYSTICK_ENABLE 0x00000001 | |
#define portNVIC_PENDSV_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 16 ) | |
#define portNVIC_SYSTICK_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 24 ) | |
/* Masks off all bits but the VECTACTIVE bits in the ICSR register. */ | |
#define portVECTACTIVE_MASK ( 0xFFUL ) | |
/* Constants required to manipulate the VFP. */ | |
#define portFPCCR ( ( volatile uint32_t * ) 0xe000ef34 ) /* Floating point context control register. */ | |
#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL ) | |
/* Constants required to set up the initial stack. */ | |
#define portINITIAL_XPSR ( 0x01000000 ) | |
#define portINITIAL_EXEC_RETURN ( 0xfffffffd ) | |
/* Let the user override the pre-loading of the initial LR with the address of | |
prvTaskExitError() in case is messes up unwinding of the stack in the | |
debugger. */ | |
#ifdef configTASK_RETURN_ADDRESS | |
#define portTASK_RETURN_ADDRESS configTASK_RETURN_ADDRESS | |
#else | |
#define portTASK_RETURN_ADDRESS prvTaskExitError | |
#endif | |
/* The priority used by the kernel is assigned to a variable to make access | |
from inline assembler easier. */ | |
const uint32_t ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY; | |
/* Each task maintains its own interrupt status in the critical nesting | |
variable. */ | |
static uint32_t ulCriticalNesting = 0xaaaaaaaaUL; | |
/* | |
* Setup the timer to generate the tick interrupts. | |
*/ | |
static void prvSetupTimerInterrupt( void ); | |
/* | |
* Exception handlers. | |
*/ | |
void SysTick_Handler( void ); | |
/* | |
* Functions defined in port_asm.asm. | |
*/ | |
extern void vPortEnableVFP( void ); | |
extern void vPortStartFirstTask( void ); | |
/* | |
* Used to catch tasks that attempt to return from their implementing function. | |
*/ | |
static void prvTaskExitError( void ); | |
/* This exists purely to allow the const to be used from within the | |
port_asm.asm assembly file. */ | |
const uint32_t ulMaxSyscallInterruptPriorityConst = configMAX_SYSCALL_INTERRUPT_PRIORITY; | |
/*-----------------------------------------------------------*/ | |
/* | |
* See header file for description. | |
*/ | |
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters ) | |
{ | |
/* Simulate the stack frame as it would be created by a context switch | |
interrupt. */ | |
/* Offset added to account for the way the MCU uses the stack on entry/exit | |
of interrupts, and to ensure alignment. */ | |
pxTopOfStack--; | |
*pxTopOfStack = portINITIAL_XPSR; /* xPSR */ | |
pxTopOfStack--; | |
*pxTopOfStack = ( StackType_t ) pxCode; /* PC */ | |
pxTopOfStack--; | |
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR */ | |
/* Save code space by skipping register initialisation. */ | |
pxTopOfStack -= 5; /* R12, R3, R2 and R1. */ | |
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0 */ | |
/* A save method is being used that requires each task to maintain its | |
own exec return value. */ | |
pxTopOfStack--; | |
*pxTopOfStack = portINITIAL_EXEC_RETURN; | |
pxTopOfStack -= 8; /* R11, R10, R9, R8, R7, R6, R5 and R4. */ | |
return pxTopOfStack; | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvTaskExitError( void ) | |
{ | |
/* A function that implements a task must not exit or attempt to return to | |
its caller as there is nothing to return to. If a task wants to exit it | |
should instead call vTaskDelete( NULL ). | |
Artificially force an assert() to be triggered if configASSERT() is | |
defined, then stop here so application writers can catch the error. */ | |
configASSERT( ulCriticalNesting == ~0UL ); | |
portDISABLE_INTERRUPTS(); | |
for( ;; ); | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* See header file for description. | |
*/ | |
BaseType_t xPortStartScheduler( void ) | |
{ | |
/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. | |
See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */ | |
configASSERT( ( configMAX_SYSCALL_INTERRUPT_PRIORITY ) ); | |
/* Make PendSV and SysTick the lowest priority interrupts. */ | |
*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI; | |
*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI; | |
/* Start the timer that generates the tick ISR. Interrupts are disabled | |
here already. */ | |
prvSetupTimerInterrupt(); | |
/* Initialise the critical nesting count ready for the first task. */ | |
ulCriticalNesting = 0; | |
/* Ensure the VFP is enabled - it should be anyway. */ | |
vPortEnableVFP(); | |
/* Lazy save always. */ | |
*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS; | |
/* Start the first task. */ | |
vPortStartFirstTask(); | |
/* Should not get here! */ | |
return 0; | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortEndScheduler( void ) | |
{ | |
/* Not implemented in ports where there is nothing to return to. | |
Artificially force an assert. */ | |
configASSERT( ulCriticalNesting == 1000UL ); | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortYield( void ) | |
{ | |
/* Set a PendSV to request a context switch. */ | |
*(portNVIC_INT_CTRL) = portNVIC_PENDSVSET; | |
/* Barriers are normally not required but do ensure the code is completely | |
within the specified behaviour for the architecture. */ | |
__DSB(); | |
__ISB(); | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortEnterCritical( void ) | |
{ | |
portDISABLE_INTERRUPTS(); | |
ulCriticalNesting++; | |
__DSB(); | |
__ISB(); | |
/* This is not the interrupt safe version of the enter critical function so | |
assert() if it is being called from an interrupt context. Only API | |
functions that end in "FromISR" can be used in an interrupt. Only assert if | |
the critical nesting count is 1 to protect against recursive calls if the | |
assert function also uses a critical section. */ | |
if( ulCriticalNesting == 1 ) | |
{ | |
configASSERT( ( ( *(portNVIC_INT_CTRL) ) & portVECTACTIVE_MASK ) == 0 ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortExitCritical( void ) | |
{ | |
configASSERT( ulCriticalNesting ); | |
ulCriticalNesting--; | |
if( ulCriticalNesting == 0 ) | |
{ | |
portENABLE_INTERRUPTS(); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
void SysTick_Handler( void ) | |
{ | |
uint32_t ulDummy; | |
ulDummy = portSET_INTERRUPT_MASK_FROM_ISR(); | |
{ | |
if( xTaskIncrementTick() != pdFALSE ) | |
{ | |
/* Pend a context switch. */ | |
*(portNVIC_INT_CTRL) = portNVIC_PENDSVSET; | |
} | |
} | |
portCLEAR_INTERRUPT_MASK_FROM_ISR( ulDummy ); | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* Setup the systick timer to generate the tick interrupts at the required | |
* frequency. | |
*/ | |
void prvSetupTimerInterrupt( void ) | |
{ | |
/* Configure SysTick to interrupt at the requested rate. */ | |
*(portNVIC_SYSTICK_LOAD) = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL; | |
*(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE; | |
} | |
/*-----------------------------------------------------------*/ | |