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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Source/] [portable/] [IAR/] [STR71x/] [port.c] - Rev 820
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/* FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd. *************************************************************************** * * * If you are: * * * * + New to FreeRTOS, * * + Wanting to learn FreeRTOS or multitasking in general quickly * * + Looking for basic training, * * + Wanting to improve your FreeRTOS skills and productivity * * * * then take a look at the FreeRTOS books - available as PDF or paperback * * * * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * * http://www.FreeRTOS.org/Documentation * * * * A pdf reference manual is also available. Both are usually delivered * * to your inbox within 20 minutes to two hours when purchased between 8am * * and 8pm GMT (although please allow up to 24 hours in case of * * exceptional circumstances). 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 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. 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! 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 ST STR71x ARM7 * port. *----------------------------------------------------------*/ /* Library includes. */ #include "wdg.h" #include "eic.h" /* Standard includes. */ #include <stdlib.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 ) #define portMICROS_PER_SECOND 1000000 /*-----------------------------------------------------------*/ /* Setup the watchdog to generate the tick interrupts. */ static void prvSetupTimerInterrupt( 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 long ulCriticalNesting = ( unsigned long ) 9999; /* Tick interrupt routines for cooperative and preemptive operation respectively. The preemptive version is not defined as __irq as it is called from an asm wrapper function. */ __arm __irq void vPortNonPreemptiveTick( void ); void vPortPreemptiveTick( 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; /* 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; if( ( ( unsigned long ) pxCode & 0x01UL ) != 0x00UL ) { /* We want the task to start in thumb mode. */ *pxTopOfStack |= portTHUMB_MODE_BIT; } 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. */ } /*-----------------------------------------------------------*/ /* The cooperative scheduler requires a normal IRQ service routine to simply increment the system tick. */ __arm __irq void vPortNonPreemptiveTick( void ) { /* 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(); /* Clear the interrupt in the watchdog and EIC. */ WDG->SR = 0x0000; portCLEAR_EIC(); } /*-----------------------------------------------------------*/ /* This function is called from an asm wrapper, so does not require the __irq keyword. */ void vPortPreemptiveTick( void ) { /* Increment the tick counter. */ vTaskIncrementTick(); /* The new tick value might unblock a task. Ensure the highest task that is ready to execute is the task that will execute when the tick ISR exits. */ vTaskSwitchContext(); /* Clear the interrupt in the watchdog and EIC. */ WDG->SR = 0x0000; portCLEAR_EIC(); } /*-----------------------------------------------------------*/ static void prvSetupTimerInterrupt( void ) { /* Set the watchdog up to generate a periodic tick. */ WDG_ECITConfig( DISABLE ); WDG_CntOnOffConfig( DISABLE ); WDG_PeriodValueConfig( portMICROS_PER_SECOND / configTICK_RATE_HZ ); /* Setup the tick interrupt in the EIC. */ EIC_IRQChannelPriorityConfig( WDG_IRQChannel, 1 ); EIC_IRQChannelConfig( WDG_IRQChannel, ENABLE ); EIC_IRQConfig( ENABLE ); WDG_ECITConfig( ENABLE ); /* Start the timer - interrupts are actually disabled at this point so it is safe to do this here. */ WDG_CntOnOffConfig( ENABLE ); } /*-----------------------------------------------------------*/ __arm __interwork void vPortEnterCritical( void ) { /* Disable interrupts first! */ __disable_interrupt(); /* 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++; } /*-----------------------------------------------------------*/ __arm __interwork 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_interrupt(); } } } /*-----------------------------------------------------------*/
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