340 lines
11 KiB
C
340 lines
11 KiB
C
/*
|
|
* FreeRTOS Kernel V10.2.1
|
|
* Copyright (C) 2019 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!
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include "FreeRTOS.h"
|
|
#include "task.h"
|
|
|
|
/*-----------------------------------------------------------
|
|
* Implementation of functions defined in portable.h for the AVR/IAR port.
|
|
*----------------------------------------------------------*/
|
|
|
|
/* Start tasks with interrupts enables. */
|
|
#define portFLAGS_INT_ENABLED ( ( StackType_t ) 0x80 )
|
|
|
|
/* Hardware constants for timer 1. */
|
|
#define portCLEAR_COUNTER_ON_MATCH ( ( uint8_t ) 0x08 )
|
|
#define portPRESCALE_64 ( ( uint8_t ) 0x03 )
|
|
#define portCLOCK_PRESCALER ( ( uint32_t ) 64 )
|
|
#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE ( ( uint8_t ) 0x10 )
|
|
|
|
/* The number of bytes used on the hardware stack by the task start address. */
|
|
#define portBYTES_USED_BY_RETURN_ADDRESS ( 2 )
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* Stores the critical section nesting. This must not be initialised to 0.
|
|
It will be initialised when a task starts. */
|
|
#define portNO_CRITICAL_NESTING ( ( UBaseType_t ) 0 )
|
|
UBaseType_t uxCriticalNesting = 0x50;
|
|
|
|
|
|
/*
|
|
* Perform hardware setup to enable ticks from timer 1, compare match A.
|
|
*/
|
|
static void prvSetupTimerInterrupt( void );
|
|
|
|
/*
|
|
* The IAR compiler does not have full support for inline assembler, so
|
|
* these are defined in the portmacro assembler file.
|
|
*/
|
|
extern void vPortYieldFromTick( void );
|
|
extern void vPortStart( void );
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* See header file for description.
|
|
*/
|
|
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
|
|
{
|
|
uint16_t usAddress;
|
|
StackType_t *pxTopOfHardwareStack;
|
|
|
|
/* Place a few bytes of known values on the bottom of the stack.
|
|
This is just useful for debugging. */
|
|
|
|
*pxTopOfStack = 0x11;
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = 0x22;
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = 0x33;
|
|
pxTopOfStack--;
|
|
|
|
/* Remember where the top of the hardware stack is - this is required
|
|
below. */
|
|
pxTopOfHardwareStack = pxTopOfStack;
|
|
|
|
|
|
/* Simulate how the stack would look after a call to vPortYield(). */
|
|
|
|
/*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */
|
|
|
|
|
|
|
|
/* The IAR compiler requires two stacks per task. First there is the
|
|
hardware call stack which uses the AVR stack pointer. Second there is the
|
|
software stack (local variables, parameter passing, etc.) which uses the
|
|
AVR Y register.
|
|
|
|
This function places both stacks within the memory block passed in as the
|
|
first parameter. The hardware stack is placed at the bottom of the memory
|
|
block. A gap is then left for the hardware stack to grow. Next the software
|
|
stack is placed. The amount of space between the software and hardware
|
|
stacks is defined by configCALL_STACK_SIZE.
|
|
|
|
|
|
|
|
The first part of the stack is the hardware stack. Place the start
|
|
address of the task on the hardware stack. */
|
|
usAddress = ( uint16_t ) pxCode;
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
usAddress >>= 8;
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
|
|
/* Leave enough space for the hardware stack before starting the software
|
|
stack. The '- 2' is because we have already used two spaces for the
|
|
address of the start of the task. */
|
|
pxTopOfStack -= ( configCALL_STACK_SIZE - 2 );
|
|
|
|
|
|
|
|
/* Next simulate the stack as if after a call to portSAVE_CONTEXT().
|
|
portSAVE_CONTEXT places the flags on the stack immediately after r0
|
|
to ensure the interrupts get disabled as soon as possible, and so ensuring
|
|
the stack use is minimal should a context switch interrupt occur. */
|
|
*pxTopOfStack = ( StackType_t ) 0x00; /* R0 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = portFLAGS_INT_ENABLED;
|
|
pxTopOfStack--;
|
|
|
|
/* Next place the address of the hardware stack. This is required so
|
|
the AVR stack pointer can be restored to point to the hardware stack. */
|
|
pxTopOfHardwareStack -= portBYTES_USED_BY_RETURN_ADDRESS;
|
|
usAddress = ( uint16_t ) pxTopOfHardwareStack;
|
|
|
|
/* SPL */
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
/* SPH */
|
|
usAddress >>= 8;
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
|
|
|
|
|
|
/* Now the remaining registers. */
|
|
*pxTopOfStack = ( StackType_t ) 0x01; /* R1 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x02; /* R2 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x03; /* R3 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x04; /* R4 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x05; /* R5 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x06; /* R6 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x07; /* R7 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x08; /* R8 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x09; /* R9 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x10; /* R10 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x11; /* R11 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x12; /* R12 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x13; /* R13 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x14; /* R14 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x15; /* R15 */
|
|
pxTopOfStack--;
|
|
|
|
/* Place the parameter on the stack in the expected location. */
|
|
usAddress = ( uint16_t ) pvParameters;
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
usAddress >>= 8;
|
|
*pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff );
|
|
pxTopOfStack--;
|
|
|
|
*pxTopOfStack = ( StackType_t ) 0x18; /* R18 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x19; /* R19 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x20; /* R20 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x21; /* R21 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x22; /* R22 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x23; /* R23 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x24; /* R24 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x25; /* R25 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x26; /* R26 X */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x27; /* R27 */
|
|
pxTopOfStack--;
|
|
|
|
/* The Y register is not stored as it is used as the software stack and
|
|
gets saved into the task control block. */
|
|
|
|
*pxTopOfStack = ( StackType_t ) 0x30; /* R30 Z */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( StackType_t ) 0x031; /* R31 */
|
|
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = portNO_CRITICAL_NESTING; /* Critical nesting is zero when the task starts. */
|
|
|
|
/*lint +e950 +e611 +e923 */
|
|
|
|
return pxTopOfStack;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
BaseType_t xPortStartScheduler( void )
|
|
{
|
|
/* Setup the hardware to generate the tick. */
|
|
prvSetupTimerInterrupt();
|
|
|
|
/* Restore the context of the first task that is going to run.
|
|
Normally we would just call portRESTORE_CONTEXT() here, but as the IAR
|
|
compiler does not fully support inline assembler we have to make a call.*/
|
|
vPortStart();
|
|
|
|
/* Should not get here! */
|
|
return pdTRUE;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEndScheduler( void )
|
|
{
|
|
/* It is unlikely that the AVR port will get stopped. If required simply
|
|
disable the tick interrupt here. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* Setup timer 1 compare match A to generate a tick interrupt.
|
|
*/
|
|
static void prvSetupTimerInterrupt( void )
|
|
{
|
|
uint32_t ulCompareMatch;
|
|
uint8_t ucHighByte, ucLowByte;
|
|
|
|
/* Using 16bit timer 1 to generate the tick. Correct fuses must be
|
|
selected for the configCPU_CLOCK_HZ clock. */
|
|
|
|
ulCompareMatch = configCPU_CLOCK_HZ / configTICK_RATE_HZ;
|
|
|
|
/* We only have 16 bits so have to scale to get our required tick rate. */
|
|
ulCompareMatch /= portCLOCK_PRESCALER;
|
|
|
|
/* Adjust for correct value. */
|
|
ulCompareMatch -= ( uint32_t ) 1;
|
|
|
|
/* Setup compare match value for compare match A. Interrupts are disabled
|
|
before this is called so we need not worry here. */
|
|
ucLowByte = ( uint8_t ) ( ulCompareMatch & ( uint32_t ) 0xff );
|
|
ulCompareMatch >>= 8;
|
|
ucHighByte = ( uint8_t ) ( ulCompareMatch & ( uint32_t ) 0xff );
|
|
OCR1AH = ucHighByte;
|
|
OCR1AL = ucLowByte;
|
|
|
|
/* Setup clock source and compare match behaviour. */
|
|
ucLowByte = portCLEAR_COUNTER_ON_MATCH | portPRESCALE_64;
|
|
TCCR1B = ucLowByte;
|
|
|
|
/* Enable the interrupt - this is okay as interrupt are currently globally
|
|
disabled. */
|
|
TIMSK |= portCOMPARE_MATCH_A_INTERRUPT_ENABLE;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if configUSE_PREEMPTION == 1
|
|
|
|
/*
|
|
* Tick ISR for preemptive scheduler. We can use a __task attribute as
|
|
* the context is saved at the start of vPortYieldFromTick(). The tick
|
|
* count is incremented after the context is saved.
|
|
*/
|
|
__task void SIG_OUTPUT_COMPARE1A( void )
|
|
{
|
|
vPortYieldFromTick();
|
|
asm( "reti" );
|
|
}
|
|
|
|
#else
|
|
|
|
/*
|
|
* Tick ISR for the cooperative scheduler. All this does is increment the
|
|
* tick count. We don't need to switch context, this can only be done by
|
|
* manual calls to taskYIELD();
|
|
*
|
|
* THE INTERRUPT VECTOR IS POPULATED IN portmacro.s90. DO NOT INSTALL
|
|
* IT HERE USING THE USUAL PRAGMA.
|
|
*/
|
|
__interrupt void SIG_OUTPUT_COMPARE1A( void )
|
|
{
|
|
xTaskIncrementTick();
|
|
}
|
|
#endif
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEnterCritical( void )
|
|
{
|
|
portDISABLE_INTERRUPTS();
|
|
uxCriticalNesting++;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortExitCritical( void )
|
|
{
|
|
uxCriticalNesting--;
|
|
if( uxCriticalNesting == portNO_CRITICAL_NESTING )
|
|
{
|
|
portENABLE_INTERRUPTS();
|
|
}
|
|
}
|
|
|
|
|