| /* | |
| FreeRTOS.org V5.3.1 - Copyright (C) 2003-2009 Richard Barry. | |
| This file is part of the FreeRTOS.org distribution. | |
| FreeRTOS.org 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.org without being obliged to provide | |
| the source code for any proprietary components. Alternative commercial | |
| license and support terms are also available upon request. See the | |
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| FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT | |
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| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| more details. | |
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| with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 | |
| Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
| *************************************************************************** | |
| * * | |
| * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * | |
| * * | |
| * This is a concise, step by step, 'hands on' guide that describes both * | |
| * general multitasking concepts and FreeRTOS specifics. It presents and * | |
| * explains numerous examples that are written using the FreeRTOS API. * | |
| * Full source code for all the examples is provided in an accompanying * | |
| * .zip file. * | |
| * * | |
| *************************************************************************** | |
| 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. | |
| */ | |
| /* | |
| Changes from V4.2.1 | |
| + Introduced the configKERNEL_INTERRUPT_PRIORITY definition. | |
| */ | |
| /*----------------------------------------------------------- | |
| * Implementation of functions defined in portable.h for the PIC24 port. | |
| *----------------------------------------------------------*/ | |
| /* Scheduler include files. */ | |
| #include "FreeRTOS.h" | |
| #include "task.h" | |
| /* Hardware specifics. */ | |
| #define portBIT_SET 1 | |
| #define portTIMER_PRESCALE 8 | |
| #define portINITIAL_SR 0 | |
| /* Defined for backward compatability with project created prior to | |
| FreeRTOS.org V4.3.0. */ | |
| #ifndef configKERNEL_INTERRUPT_PRIORITY | |
| #define configKERNEL_INTERRUPT_PRIORITY 1 | |
| #endif | |
| /* The program counter is only 23 bits. */ | |
| #define portUNUSED_PR_BITS 0x7f | |
| /* Records the nesting depth of calls to portENTER_CRITICAL(). */ | |
| unsigned portBASE_TYPE uxCriticalNesting = 0xef; | |
| #if configKERNEL_INTERRUPT_PRIORITY != 1 | |
| #error If configKERNEL_INTERRUPT_PRIORITY is not 1 then the #32 in the following macros needs changing to equal the portINTERRUPT_BITS value, which is ( configKERNEL_INTERRUPT_PRIORITY << 5 ) | |
| #endif | |
| #ifdef MPLAB_PIC24_PORT | |
| #define portRESTORE_CONTEXT() \ | |
| asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \ | |
| "MOV [W0], W15 \n" \ | |
| "POP W0 \n" /* Restore the critical nesting counter for the task. */ \ | |
| "MOV W0, _uxCriticalNesting \n" \ | |
| "POP PSVPAG \n" \ | |
| "POP CORCON \n" \ | |
| "POP TBLPAG \n" \ | |
| "POP RCOUNT \n" /* Restore the registers from the stack. */ \ | |
| "POP W14 \n" \ | |
| "POP.D W12 \n" \ | |
| "POP.D W10 \n" \ | |
| "POP.D W8 \n" \ | |
| "POP.D W6 \n" \ | |
| "POP.D W4 \n" \ | |
| "POP.D W2 \n" \ | |
| "POP.D W0 \n" \ | |
| "POP SR " ); | |
| #endif /* MPLAB_PIC24_PORT */ | |
| #ifdef MPLAB_DSPIC_PORT | |
| #define portRESTORE_CONTEXT() \ | |
| asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \ | |
| "MOV [W0], W15 \n" \ | |
| "POP W0 \n" /* Restore the critical nesting counter for the task. */ \ | |
| "MOV W0, _uxCriticalNesting \n" \ | |
| "POP PSVPAG \n" \ | |
| "POP CORCON \n" \ | |
| "POP DOENDH \n" \ | |
| "POP DOENDL \n" \ | |
| "POP DOSTARTH \n" \ | |
| "POP DOSTARTL \n" \ | |
| "POP DCOUNT \n" \ | |
| "POP ACCBU \n" \ | |
| "POP ACCBH \n" \ | |
| "POP ACCBL \n" \ | |
| "POP ACCAU \n" \ | |
| "POP ACCAH \n" \ | |
| "POP ACCAL \n" \ | |
| "POP TBLPAG \n" \ | |
| "POP RCOUNT \n" /* Restore the registers from the stack. */ \ | |
| "POP W14 \n" \ | |
| "POP.D W12 \n" \ | |
| "POP.D W10 \n" \ | |
| "POP.D W8 \n" \ | |
| "POP.D W6 \n" \ | |
| "POP.D W4 \n" \ | |
| "POP.D W2 \n" \ | |
| "POP.D W0 \n" \ | |
| "POP SR " ); | |
| #endif /* MPLAB_DSPIC_PORT */ | |
| /* | |
| * Setup the timer used to generate the tick interrupt. | |
| */ | |
| static void prvSetupTimerInterrupt( void ); | |
| /* | |
| * See header file for description. | |
| */ | |
| portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters ) | |
| { | |
| unsigned portSHORT usCode; | |
| portBASE_TYPE i; | |
| const portSTACK_TYPE xInitialStack[] = | |
| { | |
| 0x1111, /* W1 */ | |
| 0x2222, /* W2 */ | |
| 0x3333, /* W3 */ | |
| 0x4444, /* W4 */ | |
| 0x5555, /* W5 */ | |
| 0x6666, /* W6 */ | |
| 0x7777, /* W7 */ | |
| 0x8888, /* W8 */ | |
| 0x9999, /* W9 */ | |
| 0xaaaa, /* W10 */ | |
| 0xbbbb, /* W11 */ | |
| 0xcccc, /* W12 */ | |
| 0xdddd, /* W13 */ | |
| 0xeeee, /* W14 */ | |
| 0xcdce, /* RCOUNT */ | |
| 0xabac, /* TBLPAG */ | |
| /* dsPIC specific registers. */ | |
| #ifdef MPLAB_DSPIC_PORT | |
| 0x0202, /* ACCAL */ | |
| 0x0303, /* ACCAH */ | |
| 0x0404, /* ACCAU */ | |
| 0x0505, /* ACCBL */ | |
| 0x0606, /* ACCBH */ | |
| 0x0707, /* ACCBU */ | |
| 0x0808, /* DCOUNT */ | |
| 0x090a, /* DOSTARTL */ | |
| 0x1010, /* DOSTARTH */ | |
| 0x1110, /* DOENDL */ | |
| 0x1212, /* DOENDH */ | |
| #endif | |
| }; | |
| /* Setup the stack as if a yield had occurred. | |
| Save the low bytes of the program counter. */ | |
| usCode = ( unsigned portSHORT ) pxCode; | |
| *pxTopOfStack = ( portSTACK_TYPE ) usCode; | |
| pxTopOfStack++; | |
| /* Save the high byte of the program counter. This will always be zero | |
| here as it is passed in a 16bit pointer. If the address is greater than | |
| 16 bits then the pointer will point to a jump table. */ | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0; | |
| pxTopOfStack++; | |
| /* Status register with interrupts enabled. */ | |
| *pxTopOfStack = portINITIAL_SR; | |
| pxTopOfStack++; | |
| /* Parameters are passed in W0. */ | |
| *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; | |
| pxTopOfStack++; | |
| for( i = 0; i < ( sizeof( xInitialStack ) / sizeof( portSTACK_TYPE ) ); i++ ) | |
| { | |
| *pxTopOfStack = xInitialStack[ i ]; | |
| pxTopOfStack++; | |
| } | |
| *pxTopOfStack = CORCON; | |
| pxTopOfStack++; | |
| *pxTopOfStack = PSVPAG; | |
| pxTopOfStack++; | |
| /* Finally the critical nesting depth. */ | |
| *pxTopOfStack = 0x00; | |
| pxTopOfStack++; | |
| return pxTopOfStack; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| portBASE_TYPE xPortStartScheduler( void ) | |
| { | |
| /* Setup a timer for the tick ISR. */ | |
| prvSetupTimerInterrupt(); | |
| /* Restore the context of the first task to run. */ | |
| portRESTORE_CONTEXT(); | |
| /* Simulate the end of the yield function. */ | |
| asm volatile ( "return" ); | |
| /* Should not reach here. */ | |
| return pdTRUE; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortEndScheduler( void ) | |
| { | |
| /* It is unlikely that the scheduler for the PIC port will get stopped | |
| once running. If required disable the tick interrupt here, then return | |
| to xPortStartScheduler(). */ | |
| } | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * Setup a timer for a regular tick. | |
| */ | |
| static void prvSetupTimerInterrupt( void ) | |
| { | |
| const unsigned portLONG ulCompareMatch = ( configCPU_CLOCK_HZ / portTIMER_PRESCALE ) / configTICK_RATE_HZ; | |
| /* Prescale of 8. */ | |
| T1CON = 0; | |
| TMR1 = 0; | |
| PR1 = ( unsigned portSHORT ) ulCompareMatch; | |
| /* Setup timer 1 interrupt priority. */ | |
| IPC0bits.T1IP = configKERNEL_INTERRUPT_PRIORITY; | |
| /* Clear the interrupt as a starting condition. */ | |
| IFS0bits.T1IF = 0; | |
| /* Enable the interrupt. */ | |
| IEC0bits.T1IE = 1; | |
| /* Setup the prescale value. */ | |
| T1CONbits.TCKPS0 = 1; | |
| T1CONbits.TCKPS1 = 0; | |
| /* Start the timer. */ | |
| T1CONbits.TON = 1; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortEnterCritical( void ) | |
| { | |
| portDISABLE_INTERRUPTS(); | |
| uxCriticalNesting++; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortExitCritical( void ) | |
| { | |
| uxCriticalNesting--; | |
| if( uxCriticalNesting == 0 ) | |
| { | |
| portENABLE_INTERRUPTS(); | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void __attribute__((__interrupt__, auto_psv)) _T1Interrupt( void ) | |
| { | |
| /* Clear the timer interrupt. */ | |
| IFS0bits.T1IF = 0; | |
| vTaskIncrementTick(); | |
| #if configUSE_PREEMPTION == 1 | |
| portYIELD(); | |
| #endif | |
| } |