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/*
FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.
***************************************************************************
* *
* FreeRTOS tutorial books are available in pdf and paperback. *
* Complete, revised, and edited pdf reference manuals are also *
* available. *
* *
* Purchasing FreeRTOS documentation will not only help you, by *
* ensuring you get running as quickly as possible and with an *
* in-depth knowledge of how to use FreeRTOS, it will also help *
* the FreeRTOS project to continue with its mission of providing *
* professional grade, cross platform, de facto standard solutions *
* for microcontrollers - completely free of charge! *
* *
* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
* *
* Thank you for using FreeRTOS, and thank you for your support! *
* *
***************************************************************************
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. See the GNU General Public License for
more details. You should have received a copy of the GNU General Public
License and the FreeRTOS license exception along with FreeRTOS; if not it
can be viewed here: http://www.freertos.org/a00114.html and also obtained
by writing to Richard Barry, contact details for whom are available on the
FreeRTOS WEB site.
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong? *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, training, latest information,
license and contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool.
Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
the code with commercial support, indemnification, and middleware, under
the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
provide a safety engineered and independently SIL3 certified version under
the SafeRTOS brand: http://www.SafeRTOS.com.
*/
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the ST STR75x ARM7
* port.
*----------------------------------------------------------*/
/* Library includes. */
#include "75x_tb.h"
#include "75x_eic.h"
/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.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 handle critical sections. */
#define portNO_CRITICAL_NESTING ( ( unsigned long ) 0 )
/* Prescale used on the timer clock when calculating the tick period. */
#define portPRESCALE 20
/*-----------------------------------------------------------*/
/* Setup the TB to generate the tick interrupts. */
static void prvSetupTimerInterrupt( void );
/*-----------------------------------------------------------*/
/*
* 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;
/* To ensure asserts in tasks.c don't fail, although in this case the assert
is not really required. */
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 vPortISRStartFirstTask( void );
/* Start the timer that generates the tick ISR. Interrupts are disabled
here already. */
prvSetupTimerInterrupt();
/* Start the first task. */
vPortISRStartFirstTask();
/* 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 void prvSetupTimerInterrupt( void )
{
EIC_IRQInitTypeDef EIC_IRQInitStructure;
TB_InitTypeDef TB_InitStructure;
/* Setup the EIC for the TB. */
EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;
EIC_IRQInitStructure.EIC_IRQChannel = TB_IRQChannel;
EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;
EIC_IRQInit(&EIC_IRQInitStructure);
/* Setup the TB for the generation of the tick interrupt. */
TB_InitStructure.TB_Mode = TB_Mode_Timing;
TB_InitStructure.TB_CounterMode = TB_CounterMode_Down;
TB_InitStructure.TB_Prescaler = portPRESCALE - 1;
TB_InitStructure.TB_AutoReload = ( ( configCPU_CLOCK_HZ / portPRESCALE ) / configTICK_RATE_HZ );
TB_Init(&TB_InitStructure);
/* Enable TB Update interrupt */
TB_ITConfig(TB_IT_Update, ENABLE);
/* Clear TB Update interrupt pending bit */
TB_ClearITPendingBit(TB_IT_Update);
/* Enable TB */
TB_Cmd(ENABLE);
}
/*-----------------------------------------------------------*/
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