| 1 |
572 |
jeremybenn |
/*
|
| 2 |
|
|
FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
|
| 3 |
|
|
|
| 4 |
|
|
***************************************************************************
|
| 5 |
|
|
* *
|
| 6 |
|
|
* If you are: *
|
| 7 |
|
|
* *
|
| 8 |
|
|
* + New to FreeRTOS, *
|
| 9 |
|
|
* + Wanting to learn FreeRTOS or multitasking in general quickly *
|
| 10 |
|
|
* + Looking for basic training, *
|
| 11 |
|
|
* + Wanting to improve your FreeRTOS skills and productivity *
|
| 12 |
|
|
* *
|
| 13 |
|
|
* then take a look at the FreeRTOS books - available as PDF or paperback *
|
| 14 |
|
|
* *
|
| 15 |
|
|
* "Using the FreeRTOS Real Time Kernel - a Practical Guide" *
|
| 16 |
|
|
* http://www.FreeRTOS.org/Documentation *
|
| 17 |
|
|
* *
|
| 18 |
|
|
* A pdf reference manual is also available. Both are usually delivered *
|
| 19 |
|
|
* to your inbox within 20 minutes to two hours when purchased between 8am *
|
| 20 |
|
|
* and 8pm GMT (although please allow up to 24 hours in case of *
|
| 21 |
|
|
* exceptional circumstances). Thank you for your support! *
|
| 22 |
|
|
* *
|
| 23 |
|
|
***************************************************************************
|
| 24 |
|
|
|
| 25 |
|
|
This file is part of the FreeRTOS distribution.
|
| 26 |
|
|
|
| 27 |
|
|
FreeRTOS is free software; you can redistribute it and/or modify it under
|
| 28 |
|
|
the terms of the GNU General Public License (version 2) as published by the
|
| 29 |
|
|
Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
|
| 30 |
|
|
***NOTE*** The exception to the GPL is included to allow you to distribute
|
| 31 |
|
|
a combined work that includes FreeRTOS without being obliged to provide the
|
| 32 |
|
|
source code for proprietary components outside of the FreeRTOS kernel.
|
| 33 |
|
|
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
|
| 34 |
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
| 35 |
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
| 36 |
|
|
more details. You should have received a copy of the GNU General Public
|
| 37 |
|
|
License and the FreeRTOS license exception along with FreeRTOS; if not it
|
| 38 |
|
|
can be viewed here: http://www.freertos.org/a00114.html and also obtained
|
| 39 |
|
|
by writing to Richard Barry, contact details for whom are available on the
|
| 40 |
|
|
FreeRTOS WEB site.
|
| 41 |
|
|
|
| 42 |
|
|
1 tab == 4 spaces!
|
| 43 |
|
|
|
| 44 |
|
|
http://www.FreeRTOS.org - Documentation, latest information, license and
|
| 45 |
|
|
contact details.
|
| 46 |
|
|
|
| 47 |
|
|
http://www.SafeRTOS.com - A version that is certified for use in safety
|
| 48 |
|
|
critical systems.
|
| 49 |
|
|
|
| 50 |
|
|
http://www.OpenRTOS.com - Commercial support, development, porting,
|
| 51 |
|
|
licensing and training services.
|
| 52 |
|
|
*/
|
| 53 |
|
|
|
| 54 |
|
|
/*
|
| 55 |
|
|
Changes from V4.2.1
|
| 56 |
|
|
|
| 57 |
|
|
+ Introduced the configKERNEL_INTERRUPT_PRIORITY definition.
|
| 58 |
|
|
*/
|
| 59 |
|
|
|
| 60 |
|
|
/*-----------------------------------------------------------
|
| 61 |
|
|
* Implementation of functions defined in portable.h for the PIC24 port.
|
| 62 |
|
|
*----------------------------------------------------------*/
|
| 63 |
|
|
|
| 64 |
|
|
/* Scheduler include files. */
|
| 65 |
|
|
#include "FreeRTOS.h"
|
| 66 |
|
|
#include "task.h"
|
| 67 |
|
|
|
| 68 |
|
|
/* Hardware specifics. */
|
| 69 |
|
|
#define portBIT_SET 1
|
| 70 |
|
|
#define portTIMER_PRESCALE 8
|
| 71 |
|
|
#define portINITIAL_SR 0
|
| 72 |
|
|
|
| 73 |
|
|
/* Defined for backward compatability with project created prior to
|
| 74 |
|
|
FreeRTOS.org V4.3.0. */
|
| 75 |
|
|
#ifndef configKERNEL_INTERRUPT_PRIORITY
|
| 76 |
|
|
#define configKERNEL_INTERRUPT_PRIORITY 1
|
| 77 |
|
|
#endif
|
| 78 |
|
|
|
| 79 |
|
|
/* The program counter is only 23 bits. */
|
| 80 |
|
|
#define portUNUSED_PR_BITS 0x7f
|
| 81 |
|
|
|
| 82 |
|
|
/* Records the nesting depth of calls to portENTER_CRITICAL(). */
|
| 83 |
|
|
unsigned portBASE_TYPE uxCriticalNesting = 0xef;
|
| 84 |
|
|
|
| 85 |
|
|
#if configKERNEL_INTERRUPT_PRIORITY != 1
|
| 86 |
|
|
#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 )
|
| 87 |
|
|
#endif
|
| 88 |
|
|
|
| 89 |
|
|
#ifdef MPLAB_PIC24_PORT
|
| 90 |
|
|
|
| 91 |
|
|
#define portRESTORE_CONTEXT() \
|
| 92 |
|
|
asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \
|
| 93 |
|
|
"MOV [W0], W15 \n" \
|
| 94 |
|
|
"POP W0 \n" /* Restore the critical nesting counter for the task. */ \
|
| 95 |
|
|
"MOV W0, _uxCriticalNesting \n" \
|
| 96 |
|
|
"POP PSVPAG \n" \
|
| 97 |
|
|
"POP CORCON \n" \
|
| 98 |
|
|
"POP TBLPAG \n" \
|
| 99 |
|
|
"POP RCOUNT \n" /* Restore the registers from the stack. */ \
|
| 100 |
|
|
"POP W14 \n" \
|
| 101 |
|
|
"POP.D W12 \n" \
|
| 102 |
|
|
"POP.D W10 \n" \
|
| 103 |
|
|
"POP.D W8 \n" \
|
| 104 |
|
|
"POP.D W6 \n" \
|
| 105 |
|
|
"POP.D W4 \n" \
|
| 106 |
|
|
"POP.D W2 \n" \
|
| 107 |
|
|
"POP.D W0 \n" \
|
| 108 |
|
|
"POP SR " );
|
| 109 |
|
|
|
| 110 |
|
|
#endif /* MPLAB_PIC24_PORT */
|
| 111 |
|
|
|
| 112 |
|
|
#ifdef MPLAB_DSPIC_PORT
|
| 113 |
|
|
|
| 114 |
|
|
#define portRESTORE_CONTEXT() \
|
| 115 |
|
|
asm volatile( "MOV _pxCurrentTCB, W0 \n" /* Restore the stack pointer for the task. */ \
|
| 116 |
|
|
"MOV [W0], W15 \n" \
|
| 117 |
|
|
"POP W0 \n" /* Restore the critical nesting counter for the task. */ \
|
| 118 |
|
|
"MOV W0, _uxCriticalNesting \n" \
|
| 119 |
|
|
"POP PSVPAG \n" \
|
| 120 |
|
|
"POP CORCON \n" \
|
| 121 |
|
|
"POP DOENDH \n" \
|
| 122 |
|
|
"POP DOENDL \n" \
|
| 123 |
|
|
"POP DOSTARTH \n" \
|
| 124 |
|
|
"POP DOSTARTL \n" \
|
| 125 |
|
|
"POP DCOUNT \n" \
|
| 126 |
|
|
"POP ACCBU \n" \
|
| 127 |
|
|
"POP ACCBH \n" \
|
| 128 |
|
|
"POP ACCBL \n" \
|
| 129 |
|
|
"POP ACCAU \n" \
|
| 130 |
|
|
"POP ACCAH \n" \
|
| 131 |
|
|
"POP ACCAL \n" \
|
| 132 |
|
|
"POP TBLPAG \n" \
|
| 133 |
|
|
"POP RCOUNT \n" /* Restore the registers from the stack. */ \
|
| 134 |
|
|
"POP W14 \n" \
|
| 135 |
|
|
"POP.D W12 \n" \
|
| 136 |
|
|
"POP.D W10 \n" \
|
| 137 |
|
|
"POP.D W8 \n" \
|
| 138 |
|
|
"POP.D W6 \n" \
|
| 139 |
|
|
"POP.D W4 \n" \
|
| 140 |
|
|
"POP.D W2 \n" \
|
| 141 |
|
|
"POP.D W0 \n" \
|
| 142 |
|
|
"POP SR " );
|
| 143 |
|
|
|
| 144 |
|
|
#endif /* MPLAB_DSPIC_PORT */
|
| 145 |
|
|
|
| 146 |
|
|
/*
|
| 147 |
|
|
* Setup the timer used to generate the tick interrupt.
|
| 148 |
|
|
*/
|
| 149 |
|
|
static void prvSetupTimerInterrupt( void );
|
| 150 |
|
|
|
| 151 |
|
|
/*
|
| 152 |
|
|
* See header file for description.
|
| 153 |
|
|
*/
|
| 154 |
|
|
portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
|
| 155 |
|
|
{
|
| 156 |
|
|
unsigned short usCode;
|
| 157 |
|
|
portBASE_TYPE i;
|
| 158 |
|
|
|
| 159 |
|
|
const portSTACK_TYPE xInitialStack[] =
|
| 160 |
|
|
{
|
| 161 |
|
|
0x1111, /* W1 */
|
| 162 |
|
|
0x2222, /* W2 */
|
| 163 |
|
|
0x3333, /* W3 */
|
| 164 |
|
|
0x4444, /* W4 */
|
| 165 |
|
|
0x5555, /* W5 */
|
| 166 |
|
|
0x6666, /* W6 */
|
| 167 |
|
|
0x7777, /* W7 */
|
| 168 |
|
|
0x8888, /* W8 */
|
| 169 |
|
|
0x9999, /* W9 */
|
| 170 |
|
|
0xaaaa, /* W10 */
|
| 171 |
|
|
0xbbbb, /* W11 */
|
| 172 |
|
|
0xcccc, /* W12 */
|
| 173 |
|
|
0xdddd, /* W13 */
|
| 174 |
|
|
0xeeee, /* W14 */
|
| 175 |
|
|
0xcdce, /* RCOUNT */
|
| 176 |
|
|
0xabac, /* TBLPAG */
|
| 177 |
|
|
|
| 178 |
|
|
/* dsPIC specific registers. */
|
| 179 |
|
|
#ifdef MPLAB_DSPIC_PORT
|
| 180 |
|
|
0x0202, /* ACCAL */
|
| 181 |
|
|
0x0303, /* ACCAH */
|
| 182 |
|
|
0x0404, /* ACCAU */
|
| 183 |
|
|
0x0505, /* ACCBL */
|
| 184 |
|
|
0x0606, /* ACCBH */
|
| 185 |
|
|
0x0707, /* ACCBU */
|
| 186 |
|
|
0x0808, /* DCOUNT */
|
| 187 |
|
|
0x090a, /* DOSTARTL */
|
| 188 |
|
|
0x1010, /* DOSTARTH */
|
| 189 |
|
|
0x1110, /* DOENDL */
|
| 190 |
|
|
0x1212, /* DOENDH */
|
| 191 |
|
|
#endif
|
| 192 |
|
|
};
|
| 193 |
|
|
|
| 194 |
|
|
/* Setup the stack as if a yield had occurred.
|
| 195 |
|
|
|
| 196 |
|
|
Save the low bytes of the program counter. */
|
| 197 |
|
|
usCode = ( unsigned short ) pxCode;
|
| 198 |
|
|
*pxTopOfStack = ( portSTACK_TYPE ) usCode;
|
| 199 |
|
|
pxTopOfStack++;
|
| 200 |
|
|
|
| 201 |
|
|
/* Save the high byte of the program counter. This will always be zero
|
| 202 |
|
|
here as it is passed in a 16bit pointer. If the address is greater than
|
| 203 |
|
|
16 bits then the pointer will point to a jump table. */
|
| 204 |
|
|
*pxTopOfStack = ( portSTACK_TYPE ) 0;
|
| 205 |
|
|
pxTopOfStack++;
|
| 206 |
|
|
|
| 207 |
|
|
/* Status register with interrupts enabled. */
|
| 208 |
|
|
*pxTopOfStack = portINITIAL_SR;
|
| 209 |
|
|
pxTopOfStack++;
|
| 210 |
|
|
|
| 211 |
|
|
/* Parameters are passed in W0. */
|
| 212 |
|
|
*pxTopOfStack = ( portSTACK_TYPE ) pvParameters;
|
| 213 |
|
|
pxTopOfStack++;
|
| 214 |
|
|
|
| 215 |
|
|
for( i = 0; i < ( sizeof( xInitialStack ) / sizeof( portSTACK_TYPE ) ); i++ )
|
| 216 |
|
|
{
|
| 217 |
|
|
*pxTopOfStack = xInitialStack[ i ];
|
| 218 |
|
|
pxTopOfStack++;
|
| 219 |
|
|
}
|
| 220 |
|
|
|
| 221 |
|
|
*pxTopOfStack = CORCON;
|
| 222 |
|
|
pxTopOfStack++;
|
| 223 |
|
|
*pxTopOfStack = PSVPAG;
|
| 224 |
|
|
pxTopOfStack++;
|
| 225 |
|
|
|
| 226 |
|
|
/* Finally the critical nesting depth. */
|
| 227 |
|
|
*pxTopOfStack = 0x00;
|
| 228 |
|
|
pxTopOfStack++;
|
| 229 |
|
|
|
| 230 |
|
|
return pxTopOfStack;
|
| 231 |
|
|
}
|
| 232 |
|
|
/*-----------------------------------------------------------*/
|
| 233 |
|
|
|
| 234 |
|
|
portBASE_TYPE xPortStartScheduler( void )
|
| 235 |
|
|
{
|
| 236 |
|
|
/* Setup a timer for the tick ISR. */
|
| 237 |
|
|
prvSetupTimerInterrupt();
|
| 238 |
|
|
|
| 239 |
|
|
/* Restore the context of the first task to run. */
|
| 240 |
|
|
portRESTORE_CONTEXT();
|
| 241 |
|
|
|
| 242 |
|
|
/* Simulate the end of the yield function. */
|
| 243 |
|
|
asm volatile ( "return" );
|
| 244 |
|
|
|
| 245 |
|
|
/* Should not reach here. */
|
| 246 |
|
|
return pdTRUE;
|
| 247 |
|
|
}
|
| 248 |
|
|
/*-----------------------------------------------------------*/
|
| 249 |
|
|
|
| 250 |
|
|
void vPortEndScheduler( void )
|
| 251 |
|
|
{
|
| 252 |
|
|
/* It is unlikely that the scheduler for the PIC port will get stopped
|
| 253 |
|
|
once running. If required disable the tick interrupt here, then return
|
| 254 |
|
|
to xPortStartScheduler(). */
|
| 255 |
|
|
}
|
| 256 |
|
|
/*-----------------------------------------------------------*/
|
| 257 |
|
|
|
| 258 |
|
|
/*
|
| 259 |
|
|
* Setup a timer for a regular tick.
|
| 260 |
|
|
*/
|
| 261 |
|
|
static void prvSetupTimerInterrupt( void )
|
| 262 |
|
|
{
|
| 263 |
|
|
const unsigned long ulCompareMatch = ( ( configCPU_CLOCK_HZ / portTIMER_PRESCALE ) / configTICK_RATE_HZ ) - 1;
|
| 264 |
|
|
|
| 265 |
|
|
/* Prescale of 8. */
|
| 266 |
|
|
T1CON = 0;
|
| 267 |
|
|
TMR1 = 0;
|
| 268 |
|
|
|
| 269 |
|
|
PR1 = ( unsigned short ) ulCompareMatch;
|
| 270 |
|
|
|
| 271 |
|
|
/* Setup timer 1 interrupt priority. */
|
| 272 |
|
|
IPC0bits.T1IP = configKERNEL_INTERRUPT_PRIORITY;
|
| 273 |
|
|
|
| 274 |
|
|
/* Clear the interrupt as a starting condition. */
|
| 275 |
|
|
IFS0bits.T1IF = 0;
|
| 276 |
|
|
|
| 277 |
|
|
/* Enable the interrupt. */
|
| 278 |
|
|
IEC0bits.T1IE = 1;
|
| 279 |
|
|
|
| 280 |
|
|
/* Setup the prescale value. */
|
| 281 |
|
|
T1CONbits.TCKPS0 = 1;
|
| 282 |
|
|
T1CONbits.TCKPS1 = 0;
|
| 283 |
|
|
|
| 284 |
|
|
/* Start the timer. */
|
| 285 |
|
|
T1CONbits.TON = 1;
|
| 286 |
|
|
}
|
| 287 |
|
|
/*-----------------------------------------------------------*/
|
| 288 |
|
|
|
| 289 |
|
|
void vPortEnterCritical( void )
|
| 290 |
|
|
{
|
| 291 |
|
|
portDISABLE_INTERRUPTS();
|
| 292 |
|
|
uxCriticalNesting++;
|
| 293 |
|
|
}
|
| 294 |
|
|
/*-----------------------------------------------------------*/
|
| 295 |
|
|
|
| 296 |
|
|
void vPortExitCritical( void )
|
| 297 |
|
|
{
|
| 298 |
|
|
uxCriticalNesting--;
|
| 299 |
|
|
if( uxCriticalNesting == 0 )
|
| 300 |
|
|
{
|
| 301 |
|
|
portENABLE_INTERRUPTS();
|
| 302 |
|
|
}
|
| 303 |
|
|
}
|
| 304 |
|
|
/*-----------------------------------------------------------*/
|
| 305 |
|
|
|
| 306 |
|
|
void __attribute__((__interrupt__, auto_psv)) _T1Interrupt( void )
|
| 307 |
|
|
{
|
| 308 |
|
|
/* Clear the timer interrupt. */
|
| 309 |
|
|
IFS0bits.T1IF = 0;
|
| 310 |
|
|
|
| 311 |
|
|
vTaskIncrementTick();
|
| 312 |
|
|
|
| 313 |
|
|
#if configUSE_PREEMPTION == 1
|
| 314 |
|
|
portYIELD();
|
| 315 |
|
|
#endif
|
| 316 |
|
|
}
|
