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/*
FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org 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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS.org, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
* *
* This is a concise, step by step, 'hands on' guide that describes both *
* general multitasking concepts and FreeRTOS specifics. It presents and *
* explains numerous examples that are written using the FreeRTOS API. *
* Full source code for all the examples is provided in an accompanying *
* .zip file. *
* *
***************************************************************************
***************************************************************************
Please ensure to read the configuration and relevant port sections of the
online documentation.
http://www.FreeRTOS.org - Documentation, latest information, license and
contact details.
http://www.SafeRTOS.com - A version that is certified for use in safety
critical systems.
http://www.OpenRTOS.com - Commercial support, development, porting,
licensing and training services.
*/
/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the H8S port.
*----------------------------------------------------------*/
/*-----------------------------------------------------------*/
/* When the task starts interrupts should be enabled. */
#define portINITIAL_CCR ( ( portSTACK_TYPE ) 0x00 )
/* Hardware specific constants used to generate the RTOS tick from the TPU. */
#define portCLEAR_ON_TGRA_COMPARE_MATCH ( ( unsigned portCHAR ) 0x20 )
#define portCLOCK_DIV_64 ( ( unsigned portCHAR ) 0x03 )
#define portCLOCK_DIV ( ( unsigned portLONG ) 64 )
#define portTGRA_INTERRUPT_ENABLE ( ( unsigned portCHAR ) 0x01 )
#define portTIMER_CHANNEL ( ( unsigned portCHAR ) 0x02 )
#define portMSTP13 ( ( unsigned portSHORT ) 0x2000 )
/*
* Setup TPU channel one for the RTOS tick at the requested frequency.
*/
static void prvSetupTimerInterrupt( void );
/*
* The ISR used by portYIELD(). This is installed as a trap handler.
*/
void vPortYield( void ) __attribute__ ( ( saveall, interrupt_handler ) );
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
{
unsigned portLONG ulValue;
/* This requires an even address. */
ulValue = ( unsigned portLONG ) pxTopOfStack;
if( ulValue & 1UL )
{
pxTopOfStack = pxTopOfStack - 1;
}
/* Place a few bytes of known values on the bottom of the stack.
This is just useful for debugging. */
pxTopOfStack--;
*pxTopOfStack = 0xaa;
pxTopOfStack--;
*pxTopOfStack = 0xbb;
pxTopOfStack--;
*pxTopOfStack = 0xcc;
pxTopOfStack--;
*pxTopOfStack = 0xdd;
/* The initial stack mimics an interrupt stack. First there is the program
counter (24 bits). */
ulValue = ( unsigned portLONG ) pxCode;
pxTopOfStack--;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
pxTopOfStack--;
ulValue >>= 8UL;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
pxTopOfStack--;
ulValue >>= 8UL;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
/* Followed by the CCR. */
pxTopOfStack--;
*pxTopOfStack = portINITIAL_CCR;
/* Next all the general purpose registers - with the parameters being passed
in ER0. The parameter order must match that used by the compiler when the
"saveall" function attribute is used. */
/* ER6 */
pxTopOfStack--;
*pxTopOfStack = 0x66;
pxTopOfStack--;
*pxTopOfStack = 0x66;
pxTopOfStack--;
*pxTopOfStack = 0x66;
pxTopOfStack--;
*pxTopOfStack = 0x66;
/* ER0 */
ulValue = ( unsigned portLONG ) pvParameters;
pxTopOfStack--;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
pxTopOfStack--;
ulValue >>= 8UL;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
pxTopOfStack--;
ulValue >>= 8UL;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
pxTopOfStack--;
ulValue >>= 8UL;
*pxTopOfStack = ( portSTACK_TYPE ) ( ulValue & 0xff );
/* ER1 */
pxTopOfStack--;
*pxTopOfStack = 0x11;
pxTopOfStack--;
*pxTopOfStack = 0x11;
pxTopOfStack--;
*pxTopOfStack = 0x11;
pxTopOfStack--;
*pxTopOfStack = 0x11;
/* ER2 */
pxTopOfStack--;
*pxTopOfStack = 0x22;
pxTopOfStack--;
*pxTopOfStack = 0x22;
pxTopOfStack--;
*pxTopOfStack = 0x22;
pxTopOfStack--;
*pxTopOfStack = 0x22;
/* ER3 */
pxTopOfStack--;
*pxTopOfStack = 0x33;
pxTopOfStack--;
*pxTopOfStack = 0x33;
pxTopOfStack--;
*pxTopOfStack = 0x33;
pxTopOfStack--;
*pxTopOfStack = 0x33;
/* ER4 */
pxTopOfStack--;
*pxTopOfStack = 0x44;
pxTopOfStack--;
*pxTopOfStack = 0x44;
pxTopOfStack--;
*pxTopOfStack = 0x44;
pxTopOfStack--;
*pxTopOfStack = 0x44;
/* ER5 */
pxTopOfStack--;
*pxTopOfStack = 0x55;
pxTopOfStack--;
*pxTopOfStack = 0x55;
pxTopOfStack--;
*pxTopOfStack = 0x55;
pxTopOfStack--;
*pxTopOfStack = 0x55;
return pxTopOfStack;
}
/*-----------------------------------------------------------*/
portBASE_TYPE xPortStartScheduler( void )
{
extern void * pxCurrentTCB;
/* Setup the hardware to generate the tick. */
prvSetupTimerInterrupt();
/* Restore the context of the first task that is going to run. This
mirrors the function epilogue code generated by the compiler when the
"saveall" function attribute is used. */
asm volatile (
"MOV.L @_pxCurrentTCB, ER6 \n\t"
"MOV.L @ER6, ER7 \n\t"
"LDM.L @SP+, (ER4-ER5) \n\t"
"LDM.L @SP+, (ER0-ER3) \n\t"
"MOV.L @ER7+, ER6 \n\t"
"RTE \n\t"
);
( void ) pxCurrentTCB;
/* Should not get here. */
return pdTRUE;
}
/*-----------------------------------------------------------*/
void vPortEndScheduler( void )
{
/* It is unlikely that the h8 port will get stopped. */
}
/*-----------------------------------------------------------*/
/*
* Manual context switch. This is a trap handler. The "saveall" function
* attribute is used so the context is saved by the compiler prologue. All
* we have to do is save the stack pointer.
*/
void vPortYield( void )
{
portSAVE_STACK_POINTER();
vTaskSwitchContext();
portRESTORE_STACK_POINTER();
}
/*-----------------------------------------------------------*/
/*
* The interrupt handler installed for the RTOS tick depends on whether the
* preemptive or cooperative scheduler is being used.
*/
#if( configUSE_PREEMPTION == 1 )
/*
* The preemptive scheduler is used so the ISR calls vTaskSwitchContext().
* The function prologue saves the context so all we have to do is save
* the stack pointer.
*/
void vTickISR( void ) __attribute__ ( ( saveall, interrupt_handler ) );
void vTickISR( void )
{
portSAVE_STACK_POINTER();
vTaskIncrementTick();
vTaskSwitchContext();
/* Clear the interrupt. */
TSR1 &= ~0x01;
portRESTORE_STACK_POINTER();
}
#else
/*
* The cooperative scheduler is being used so all we have to do is
* periodically increment the tick. This can just be a normal ISR and
* the "saveall" attribute is not required.
*/
void vTickISR( void ) __attribute__ ( ( interrupt_handler ) );
void vTickISR( void )
{
vTaskIncrementTick();
/* Clear the interrupt. */
TSR1 &= ~0x01;
}
#endif
/*-----------------------------------------------------------*/
/*
* Setup timer 1 compare match to generate a tick interrupt.
*/
static void prvSetupTimerInterrupt( void )
{
const unsigned portLONG ulCompareMatch = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) / portCLOCK_DIV;
/* Turn the module on. */
MSTPCR &= ~portMSTP13;
/* Configure timer 1. */
TCR1 = portCLEAR_ON_TGRA_COMPARE_MATCH | portCLOCK_DIV_64;
/* Configure the compare match value for a tick of configTICK_RATE_HZ. */
TGR1A = ulCompareMatch;
/* Start the timer and enable the interrupt - we can do this here as
interrupts are globally disabled when this function is called. */
TIER1 |= portTGRA_INTERRUPT_ENABLE;
TSTR |= portTIMER_CHANNEL;
}
/*-----------------------------------------------------------*/
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