/* | |
FreeRTOS V6.1.0 - Copyright (C) 2010 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 "FreeRTOSConfig.h" | |
#include "portasm.h" | |
IMPORT vTaskIncrementTick | |
IMPORT vTaskSwitchContext | |
IMPORT vPortSetupTimerInterrupt | |
EXPORT vTickISR | |
EXPORT vPortYield | |
EXPORT xPortStartScheduler | |
RSEG CODE | |
/* | |
* 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. | |
*/ | |
vTickISR: | |
portSAVE_CONTEXT | |
call #vTaskIncrementTick | |
#if configUSE_PREEMPTION == 1 | |
call #vTaskSwitchContext | |
#endif | |
portRESTORE_CONTEXT | |
/*-----------------------------------------------------------*/ | |
/* | |
* Manual context switch called by the portYIELD() macro. | |
*/ | |
vPortYield: | |
/* Mimic an interrupt by pushing the SR. */ | |
push SR | |
/* Now the SR is stacked we can disable interrupts. */ | |
dint | |
/* Save the context of the current task. */ | |
portSAVE_CONTEXT | |
/* Switch to the highest priority task that is ready to run. */ | |
call #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. | |
*/ | |
xPortStartScheduler: | |
/* Setup the hardware to generate the tick. Interrupts are disabled | |
when this function is called. */ | |
call #vPortSetupTimerInterrupt | |
/* Restore the context of the first task that is going to run. */ | |
portRESTORE_CONTEXT | |
/*-----------------------------------------------------------*/ | |
/* Install vTickISR as the timer A0 interrupt. */ | |
ASEG | |
ORG 0xFFE0 + TIMERA0_VECTOR | |
_vTickISR_: DC16 vTickISR | |
END | |