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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.
*/
#include "msp430.h"
#include "FreeRTOSConfig.h"
#include "data_model.h"
IMPORT vTaskIncrementTick
IMPORT vTaskSwitchContext
IMPORT vPortSetupTimerInterrupt
IMPORT pxCurrentTCB
IMPORT usCriticalNesting
EXPORT vPortTickISR
EXPORT vPortYield
EXPORT xPortStartScheduler
portSAVE_CONTEXT macro
/* Save the remaining registers. */
pushm_x #12, r15
mov.w &usCriticalNesting, r14
push_x r14
mov_x &pxCurrentTCB, r12
mov_x sp, 0( r12 )
endm
/*-----------------------------------------------------------*/
portRESTORE_CONTEXT macro
mov_x &pxCurrentTCB, r12
mov_x @r12, sp
pop_x r15
mov.w r15, &usCriticalNesting
popm_x #12, r15
/* The last thing on the stack will be the status register.
Ensure the power down bits are clear ready for the next
time this power down register is popped from the stack. */
bic.w #0xf0, 0( sp )
pop.w sr
reta
endm
/*-----------------------------------------------------------*/
/*
* The RTOS tick ISR.
*
* If the cooperative scheduler is in use this simply increments the tick
* count.
*
* If the preemptive scheduler is in use a context switch can also occur.
*/
RSEG CODE
EVEN
vPortTickISR:
/* The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
to save it manually before it gets modified (interrupts get disabled). */
push.w sr
portSAVE_CONTEXT
calla #vTaskIncrementTick
#if configUSE_PREEMPTION == 1
calla #vTaskSwitchContext
#endif
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
/*
* Manual context switch called by the portYIELD() macro.
*/
EVEN
vPortYield:
/* The sr needs saving before it is modified. */
push.w sr
/* Now the SR is stacked we can disable interrupts. */
dint
nop
/* Save the context of the current task. */
portSAVE_CONTEXT
/* Select the next task to run. */
calla #vTaskSwitchContext
/* Restore the context of the new task. */
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
/*
* Start off the scheduler by initialising the RTOS tick timer, then restoring
* the context of the first task.
*/
EVEN
xPortStartScheduler:
/* Setup the hardware to generate the tick. Interrupts are disabled
when this function is called. */
calla #vPortSetupTimerInterrupt
/* Restore the context of the first task that is going to run. */
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
END