You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
274 lines
9.0 KiB
C
274 lines
9.0 KiB
C
/*
|
|
FreeRTOS V5.4.0 - Copyright (C) 2003-2009 Richard Barry.
|
|
|
|
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 exception 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.
|
|
Alternative commercial license and support terms are also available upon
|
|
request. See the licensing section of http://www.FreeRTOS.org for full
|
|
license details.
|
|
|
|
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. See the GNU General Public License for
|
|
more details.
|
|
|
|
You should have received a copy of the GNU General Public License along
|
|
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
|
|
Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
|
|
|
|
***************************************************************************
|
|
* *
|
|
* Looking for a quick start? Then check out the FreeRTOS eBook! *
|
|
* See http://www.FreeRTOS.org/Documentation for details *
|
|
* *
|
|
***************************************************************************
|
|
|
|
1 tab == 4 spaces!
|
|
|
|
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.
|
|
*/
|
|
|
|
/*-----------------------------------------------------------
|
|
* Implementation of functions defined in portable.h for the Atmel ARM7 port.
|
|
*----------------------------------------------------------*/
|
|
|
|
|
|
/* Standard includes. */
|
|
#include <stdlib.h>
|
|
|
|
/* Scheduler includes. */
|
|
#include "FreeRTOS.h"
|
|
#include "task.h"
|
|
|
|
/* Hardware includes. */
|
|
#include <board.h>
|
|
#include <pio/pio.h>
|
|
#include <pio/pio_it.h>
|
|
#include <pit/pit.h>
|
|
#include <aic/aic.h>
|
|
#include <tc/tc.h>
|
|
#include <utility/led.h>
|
|
#include <utility/trace.h>
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* Constants required to setup the initial stack. */
|
|
#define portINITIAL_SPSR ( ( portSTACK_TYPE ) 0x1f ) /* System mode, ARM mode, interrupts enabled. */
|
|
#define portTHUMB_MODE_BIT ( ( portSTACK_TYPE ) 0x20 )
|
|
#define portINSTRUCTION_SIZE ( ( portSTACK_TYPE ) 4 )
|
|
|
|
/* Constants required to setup the PIT. */
|
|
#define port1MHz_IN_Hz ( 1000000ul )
|
|
#define port1SECOND_IN_uS ( 1000000.0 )
|
|
|
|
/* Constants required to handle critical sections. */
|
|
#define portNO_CRITICAL_NESTING ( ( unsigned portLONG ) 0 )
|
|
|
|
|
|
#define portINT_LEVEL_SENSITIVE 0
|
|
#define portPIT_ENABLE ( ( unsigned portSHORT ) 0x1 << 24 )
|
|
#define portPIT_INT_ENABLE ( ( unsigned portSHORT ) 0x1 << 25 )
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* Setup the PIT to generate the tick interrupts. */
|
|
static void prvSetupTimerInterrupt( void );
|
|
|
|
/* The PIT interrupt handler - the RTOS tick. */
|
|
static void vPortTickISR( void );
|
|
|
|
/* ulCriticalNesting will get set to zero when the first task starts. It
|
|
cannot be initialised to 0 as this will cause interrupts to be enabled
|
|
during the kernel initialisation process. */
|
|
unsigned portLONG ulCriticalNesting = ( unsigned portLONG ) 9999;
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* Initialise the stack of a task to look exactly as if a call to
|
|
* portSAVE_CONTEXT had been called.
|
|
*
|
|
* See header file for description.
|
|
*/
|
|
portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
|
|
{
|
|
portSTACK_TYPE *pxOriginalTOS;
|
|
|
|
pxOriginalTOS = pxTopOfStack;
|
|
|
|
/* Setup the initial stack of the task. The stack is set exactly as
|
|
expected by the portRESTORE_CONTEXT() macro. */
|
|
|
|
/* First on the stack is the return address - which in this case is the
|
|
start of the task. The offset is added to make the return address appear
|
|
as it would within an IRQ ISR. */
|
|
*pxTopOfStack = ( portSTACK_TYPE ) pxCode + portINSTRUCTION_SIZE;
|
|
pxTopOfStack--;
|
|
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0xaaaaaaaa; /* R14 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) pxOriginalTOS; /* Stack used when task starts goes in R13. */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x12121212; /* R12 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x11111111; /* R11 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x10101010; /* R10 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x09090909; /* R9 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x08080808; /* R8 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x07070707; /* R7 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x06060606; /* R6 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x05050505; /* R5 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x04040404; /* R4 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x03030303; /* R3 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x02020202; /* R2 */
|
|
pxTopOfStack--;
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0x01010101; /* R1 */
|
|
pxTopOfStack--;
|
|
|
|
/* When the task starts is will expect to find the function parameter in
|
|
R0. */
|
|
*pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */
|
|
pxTopOfStack--;
|
|
|
|
/* The status register is set for system mode, with interrupts enabled. */
|
|
*pxTopOfStack = ( portSTACK_TYPE ) portINITIAL_SPSR;
|
|
|
|
#ifdef THUMB_INTERWORK
|
|
{
|
|
/* We want the task to start in thumb mode. */
|
|
*pxTopOfStack |= portTHUMB_MODE_BIT;
|
|
}
|
|
#endif
|
|
|
|
pxTopOfStack--;
|
|
|
|
/* Interrupt flags cannot always be stored on the stack and will
|
|
instead be stored in a variable, which is then saved as part of the
|
|
tasks context. */
|
|
*pxTopOfStack = portNO_CRITICAL_NESTING;
|
|
|
|
return pxTopOfStack;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
portBASE_TYPE xPortStartScheduler( void )
|
|
{
|
|
extern void vPortStartFirstTask( void );
|
|
|
|
/* Start the timer that generates the tick ISR. Interrupts are disabled
|
|
here already. */
|
|
prvSetupTimerInterrupt();
|
|
|
|
/* Start the first task. */
|
|
vPortStartFirstTask();
|
|
|
|
/* Should not get here! */
|
|
return 0;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEndScheduler( void )
|
|
{
|
|
/* It is unlikely that the ARM port will require this function as there
|
|
is nothing to return to. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static __arm void vPortTickISR( void )
|
|
{
|
|
volatile unsigned portLONG ulDummy;
|
|
|
|
/* Increment the tick count - which may wake some tasks but as the
|
|
preemptive scheduler is not being used any woken task is not given
|
|
processor time no matter what its priority. */
|
|
vTaskIncrementTick();
|
|
|
|
#if configUSE_PREEMPTION == 1
|
|
vTaskSwitchContext();
|
|
#endif
|
|
|
|
/* Clear the PIT interrupt. */
|
|
ulDummy = AT91C_BASE_PITC->PITC_PIVR;
|
|
|
|
/* To remove compiler warning. */
|
|
( void ) ulDummy;
|
|
|
|
/* The AIC is cleared in the asm wrapper, outside of this function. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvSetupTimerInterrupt( void )
|
|
{
|
|
const unsigned portLONG ulPeriodIn_uS = ( 1.0 / ( double ) configTICK_RATE_HZ ) * port1SECOND_IN_uS;
|
|
|
|
/* Setup the PIT for the required frequency. */
|
|
PIT_Init( ulPeriodIn_uS, BOARD_MCK / port1MHz_IN_Hz );
|
|
|
|
/* Setup the PIT interrupt. */
|
|
AIC_DisableIT( AT91C_ID_SYS );
|
|
AIC_ConfigureIT( AT91C_ID_SYS, AT91C_AIC_PRIOR_LOWEST, vPortTickISR );
|
|
AIC_EnableIT( AT91C_ID_SYS );
|
|
PIT_EnableIT();
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEnterCritical( void )
|
|
{
|
|
/* Disable interrupts first! */
|
|
__disable_irq();
|
|
|
|
/* Now interrupts are disabled ulCriticalNesting can be accessed
|
|
directly. Increment ulCriticalNesting to keep a count of how many times
|
|
portENTER_CRITICAL() has been called. */
|
|
ulCriticalNesting++;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortExitCritical( void )
|
|
{
|
|
if( ulCriticalNesting > portNO_CRITICAL_NESTING )
|
|
{
|
|
/* Decrement the nesting count as we are leaving a critical section. */
|
|
ulCriticalNesting--;
|
|
|
|
/* If the nesting level has reached zero then interrupts should be
|
|
re-enabled. */
|
|
if( ulCriticalNesting == portNO_CRITICAL_NESTING )
|
|
{
|
|
__enable_irq();
|
|
}
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
|
|
|
|
|
|
|
|
|