git.sur5r.net Git - freertos/blob - Demo/ColdFire_MCF5282_Eclipse/RTOSDemo/main.c

   1 /*\r
   2     FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.\r
   3 \r
   4     This file is part of the FreeRTOS distribution.\r
   5 \r
   6     FreeRTOS is free software; you can redistribute it and/or modify it    under\r
   7     the terms of the GNU General Public License (version 2) as published by the\r
   8     Free Software Foundation and modified by the FreeRTOS exception.\r
   9     **NOTE** The exception to the GPL is included to allow you to distribute a\r
  10     combined work that includes FreeRTOS without being obliged to provide the\r
  11     source code for proprietary components outside of the FreeRTOS kernel.\r
  12     Alternative commercial license and support terms are also available upon\r
  13     request.  See the licensing section of http://www.FreeRTOS.org for full\r
  14     license details.\r
  15 \r
  16     FreeRTOS is distributed in the hope that it will be useful,    but WITHOUT\r
  17     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or\r
  18     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
  19     more details.\r
  20 \r
  21     You should have received a copy of the GNU General Public License along\r
  22     with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59\r
  23     Temple Place, Suite 330, Boston, MA  02111-1307  USA.\r
  24 \r
  25 \r
  26     ***************************************************************************\r
  27     *                                                                         *\r
  28     * The FreeRTOS eBook and reference manual are available to purchase for a *\r
  29     * small fee. Help yourself get started quickly while also helping the     *\r
  30     * FreeRTOS project! See http://www.FreeRTOS.org/Documentation for details *\r
  31     *                                                                         *\r
  32     ***************************************************************************\r
  33 \r
  34     1 tab == 4 spaces!\r
  35 \r
  36     Please ensure to read the configuration and relevant port sections of the\r
  37     online documentation.\r
  38 \r
  39     http://www.FreeRTOS.org - Documentation, latest information, license and\r
  40     contact details.\r
  41 \r
  42     http://www.SafeRTOS.com - A version that is certified for use in safety\r
  43     critical systems.\r
  44 \r
  45     http://www.OpenRTOS.com - Commercial support, development, porting,\r
  46     licensing and training services.\r
  47 */\r
  48 \r
  49 \r
  50 /*\r
  51  * Creates all the demo application tasks, then starts the scheduler.  The WEB\r
  52  * documentation provides more details of the standard demo application tasks.\r
  53  * In addition to the standard demo tasks, the following tasks and tests are\r
  54  * defined and/or created within this file:\r
  55  *\r
  56  * "Check" task -  This only executes every five seconds but has a high priority\r
  57  * to ensure it gets processor time.  Its main function is to check that all the\r
  58  * standard demo tasks are still operational.  While no errors have been\r
  59  * discovered the check task will toggle an LED every 5 seconds - the toggle\r
  60  * rate increasing to 500ms being a visual indication that at least one task has\r
  61  * reported unexpected behaviour.\r
  62  *\r
  63  * "Reg test" tasks - These fill the registers with known values, then check\r
  64  * that each register still contains its expected value.  Each task uses\r
  65  * different values.  The tasks run with very low priority so get preempted very\r
  66  * frequently.  A register containing an unexpected value is indicative of an\r
  67  * error in the context switching mechanism.\r
  68  *\r
  69  */\r
  70 \r
  71 /* Standard includes. */\r
  72 #include <stdio.h>\r
  73 \r
  74 /* Scheduler includes. */\r
  75 #include "FreeRTOS.h"\r
  76 #include "task.h"\r
  77 #include "queue.h"\r
  78 #include "semphr.h"\r
  79 \r
  80 /* Demo app includes. */\r
  81 #include "BlockQ.h"\r
  82 #include "death.h"\r
  83 #include "integer.h"\r
  84 #include "flash.h"\r
  85 #include "partest.h"\r
  86 #include "semtest.h"\r
  87 #include "PollQ.h"\r
  88 #include "GenQTest.h"\r
  89 #include "QPeek.h"\r
  90 #include "recmutex.h"\r
  91 #include "IntQueue.h"\r
  92 #include "comtest2.h"\r
  93 \r
  94 /*-----------------------------------------------------------*/\r
  95 \r
  96 /* The time between cycles of the 'check' functionality - as described at the\r
  97 top of this file. */\r
  98 #define mainNO_ERROR_PERIOD                                     ( ( portTickType ) 5000 / portTICK_RATE_MS )\r
  99 \r
 100 /* The rate at which the LED controlled by the 'check' task will flash should an\r
 101 error have been detected. */\r
 102 #define mainERROR_PERIOD                                        ( ( portTickType ) 500 / portTICK_RATE_MS )\r
 103 \r
 104 /* The LED controlled by the 'check' task. */\r
 105 #define mainCHECK_LED                                           ( 3 )\r
 106 \r
 107 /* ComTest constants - there is no free LED for the comtest tasks. */\r
 108 #define mainCOM_TEST_BAUD_RATE                          ( ( unsigned portLONG ) 19200 )\r
 109 #define mainCOM_TEST_LED                                        ( 5 )\r
 110 \r
 111 /* Task priorities. */\r
 112 #define mainCOM_TEST_PRIORITY                           ( tskIDLE_PRIORITY + 2 )\r
 113 #define mainQUEUE_POLL_PRIORITY                         ( tskIDLE_PRIORITY + 2 )\r
 114 #define mainCHECK_TASK_PRIORITY                         ( tskIDLE_PRIORITY + 3 )\r
 115 #define mainSEM_TEST_PRIORITY                           ( tskIDLE_PRIORITY + 1 )\r
 116 #define mainBLOCK_Q_PRIORITY                            ( tskIDLE_PRIORITY + 2 )\r
 117 #define mainCREATOR_TASK_PRIORITY           ( tskIDLE_PRIORITY + 2 )\r
 118 #define mainINTEGER_TASK_PRIORITY           ( tskIDLE_PRIORITY )\r
 119 #define mainGEN_QUEUE_TASK_PRIORITY                     ( tskIDLE_PRIORITY )\r
 120 \r
 121 /*\r
 122  * Configure the hardware for the demo.\r
 123  */\r
 124 static void prvSetupHardware( void );\r
 125 \r
 126 /*\r
 127  * Implements the 'check' task functionality as described at the top of this\r
 128  * file.\r
 129  */\r
 130 static void prvCheckTask( void *pvParameters );\r
 131 \r
 132 /*\r
 133  * Implement the 'Reg test' functionality as described at the top of this file.\r
 134  */\r
 135 static void vRegTest1Task( void *pvParameters );\r
 136 static void vRegTest2Task( void *pvParameters );\r
 137 \r
 138 /*-----------------------------------------------------------*/\r
 139 \r
 140 /* Counters used to detect errors within the reg test tasks. */\r
 141 static volatile unsigned portLONG ulRegTest1Counter = 0x11111111, ulRegTest2Counter = 0x22222222;\r
 142 \r
 143 /*-----------------------------------------------------------*/\r
 144 \r
 145 int main( void )\r
 146 {\r
 147         /* Setup the hardware ready for this demo. */\r
 148         prvSetupHardware();\r
 149 \r
 150         /* Start the standard demo tasks. */\r
 151         vStartLEDFlashTasks( tskIDLE_PRIORITY );\r
 152         vStartBlockingQueueTasks( mainBLOCK_Q_PRIORITY );\r
 153         vStartSemaphoreTasks( mainSEM_TEST_PRIORITY );\r
 154         vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );\r
 155         vStartIntegerMathTasks( mainINTEGER_TASK_PRIORITY );\r
 156         vStartGenericQueueTasks( mainGEN_QUEUE_TASK_PRIORITY );\r
 157         vStartQueuePeekTasks();\r
 158         vStartRecursiveMutexTasks();\r
 159         vAltStartComTestTasks( mainCOM_TEST_PRIORITY, mainCOM_TEST_BAUD_RATE, mainCOM_TEST_LED );\r
 160         vStartInterruptQueueTasks();\r
 161 \r
 162         /* Start the reg test tasks - defined in this file. */\r
 163         xTaskCreate( vRegTest1Task, ( signed portCHAR * ) "Reg1", configMINIMAL_STACK_SIZE, ( void * ) &ulRegTest1Counter, tskIDLE_PRIORITY, NULL );\r
 164         xTaskCreate( vRegTest2Task, ( signed portCHAR * ) "Reg2", configMINIMAL_STACK_SIZE, ( void * ) &ulRegTest2Counter, tskIDLE_PRIORITY, NULL );\r
 165 \r
 166         /* Create the check task. */\r
 167         xTaskCreate( prvCheckTask, ( signed portCHAR * ) "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );\r
 168 \r
 169         /* The suicide tasks must be created last as they need to know how many\r
 170         tasks were running prior to their creation in order to ascertain whether\r
 171         or not the correct/expected number of tasks are running at any given time. */\r
 172     vCreateSuicidalTasks( mainCREATOR_TASK_PRIORITY );\r
 173 \r
 174         /* Start the scheduler. */\r
 175         vTaskStartScheduler();\r
 176 \r
 177     /* Will only get here if there was insufficient memory to create the idle\r
 178     task. */\r
 179         for( ;; );\r
 180 }\r
 181 /*-----------------------------------------------------------*/\r
 182 \r
 183 static void prvCheckTask( void *pvParameters )\r
 184 {\r
 185 unsigned ulTicksToWait = mainNO_ERROR_PERIOD, ulError = 0, ulLastRegTest1Count = 0, ulLastRegTest2Count = 0;\r
 186 portTickType xLastExecutionTime;\r
 187 \r
 188         ( void ) pvParameters;\r
 189 \r
 190         /* Initialise the variable used to control our iteration rate prior to\r
 191         its first use. */\r
 192         xLastExecutionTime = xTaskGetTickCount();\r
 193 \r
 194         for( ;; )\r
 195         {\r
 196                 /* Wait until it is time to run the tests again. */\r
 197                 vTaskDelayUntil( &xLastExecutionTime, ulTicksToWait );\r
 198 \r
 199                 /* Has an error been found in any task? */\r
 200                 if( xAreGenericQueueTasksStillRunning() != pdTRUE )\r
 201                 {\r
 202                         ulError |= 0x01UL;\r
 203                 }\r
 204 \r
 205                 if( xAreQueuePeekTasksStillRunning() != pdTRUE )\r
 206                 {\r
 207                         ulError |= 0x02UL;\r
 208                 }\r
 209 \r
 210                 if( xAreBlockingQueuesStillRunning() != pdTRUE )\r
 211                 {\r
 212                         ulError |= 0x04UL;\r
 213                 }\r
 214 \r
 215                 if( xAreSemaphoreTasksStillRunning() != pdTRUE )\r
 216             {\r
 217                 ulError |= 0x20UL;\r
 218             }\r
 219 \r
 220                 if( xArePollingQueuesStillRunning() != pdTRUE )\r
 221             {\r
 222                 ulError |= 0x40UL;\r
 223             }\r
 224 \r
 225                 if( xIsCreateTaskStillRunning() != pdTRUE )\r
 226             {\r
 227                 ulError |= 0x80UL;\r
 228             }\r
 229 \r
 230                 if( xAreIntegerMathsTaskStillRunning() != pdTRUE )\r
 231             {\r
 232                 ulError |= 0x100UL;\r
 233             }\r
 234 \r
 235                 if( xAreRecursiveMutexTasksStillRunning() != pdTRUE )\r
 236             {\r
 237                 ulError |= 0x200UL;\r
 238             }\r
 239 \r
 240                 if( xAreComTestTasksStillRunning() != pdTRUE )\r
 241                 {\r
 242                 ulError |= 0x400UL;\r
 243                 }\r
 244 \r
 245                 if( xAreIntQueueTasksStillRunning() != pdTRUE )\r
 246             {\r
 247                 ulError |= 0x800UL;\r
 248             }\r
 249 \r
 250                 if( ulLastRegTest1Count == ulRegTest1Counter )\r
 251                 {\r
 252                         ulError |= 0x1000UL;\r
 253                 }\r
 254 \r
 255                 if( ulLastRegTest2Count == ulRegTest2Counter )\r
 256                 {\r
 257                         ulError |= 0x1000UL;\r
 258                 }\r
 259 \r
 260                 ulLastRegTest1Count = ulRegTest1Counter;\r
 261                 ulLastRegTest2Count = ulRegTest2Counter;\r
 262 \r
 263                 /* If an error has been found then increase our cycle rate, and in so\r
 264                 going increase the rate at which the check task LED toggles. */\r
 265                 if( ulError != 0 )\r
 266                 {\r
 267                 ulTicksToWait = mainERROR_PERIOD;\r
 268                 }\r
 269 \r
 270                 /* Toggle the LED each itteration. */\r
 271                 vParTestToggleLED( mainCHECK_LED );\r
 272         }\r
 273 }\r
 274 /*-----------------------------------------------------------*/\r
 275 \r
 276 void prvSetupHardware( void )\r
 277 {\r
 278 extern void mcf5xxx_wr_cacr( unsigned portLONG );\r
 279 \r
 280         portDISABLE_INTERRUPTS();\r
 281 \r
 282         /* Enable the cache. */\r
 283         mcf5xxx_wr_cacr( MCF5XXX_CACR_CENB | MCF5XXX_CACR_CINV | MCF5XXX_CACR_DISD | MCF5XXX_CACR_CEIB | MCF5XXX_CACR_CLNF_00 );\r
 284         asm volatile( "NOP" ); /* As per errata. */\r
 285 \r
 286         /* Multiply 8Mhz reference crystal by 8 to achieve system clock of 64Mhz. */\r
 287         MCF_CLOCK_SYNCR = MCF_CLOCK_SYNCR_MFD( 2 );\r
 288 \r
 289         /* Wait for PLL to lock. */\r
 290         while( !( MCF_CLOCK_SYNSR & MCF_CLOCK_SYNSR_LOCK ) )\r
 291         {\r
 292                 __asm__ volatile ( "NOP" );\r
 293         }\r
 294 \r
 295         /* Setup the port used to toggle LEDs. */\r
 296         vParTestInitialise();\r
 297 }\r
 298 /*-----------------------------------------------------------*/\r
 299 \r
 300 void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName )\r
 301 {\r
 302         /* This will get called if a stack overflow is detected during the context\r
 303         switch.  Set configCHECK_FOR_STACK_OVERFLOWS to 2 to also check for stack\r
 304         problems within nested interrupts, but only do this for debug purposes as\r
 305         it will increase the context switch time. */\r
 306 \r
 307         ( void ) pxTask;\r
 308         ( void ) pcTaskName;\r
 309 \r
 310         for( ;; );\r
 311 }\r
 312 /*-----------------------------------------------------------*/\r
 313 \r
 314 static void vRegTest1Task( void *pvParameters )\r
 315 {\r
 316         /* Sanity check - did we receive the parameter expected? */\r
 317         if( pvParameters != &ulRegTest1Counter )\r
 318         {\r
 319                 /* Change here so the check task can detect that an error occurred. */\r
 320                 for( ;; );\r
 321         }\r
 322 \r
 323         /* Set all the registers to known values, then check that each retains its\r
 324         expected value - as described at the top of this file.  If an error is\r
 325         found then the loop counter will no longer be incremented allowing the check\r
 326         task to recognise the error. */\r
 327         asm volatile    (       "reg_test_1_start:                                              \n\t"\r
 328                                                 "       moveq           #1, %d0                                 \n\t"\r
 329                                                 "       moveq           #2, %d1                                 \n\t"\r
 330                                                 "       moveq           #3, %d2                                 \n\t"\r
 331                                                 "       moveq           #4, %d3                                 \n\t"\r
 332                                                 "       moveq           #5, %d4                                 \n\t"\r
 333                                                 "       moveq           #6, %d5                                 \n\t"\r
 334                                                 "       moveq           #7, %d6                                 \n\t"\r
 335                                                 "       moveq           #8, %d7                                 \n\t"\r
 336                                                 "       move            #9, %a0                                 \n\t"\r
 337                                                 "       move            #10, %a1                                \n\t"\r
 338                                                 "       move            #11, %a2                                \n\t"\r
 339                                                 "       move            #12, %a3                                \n\t"\r
 340                                                 "       move            #13, %a4                                \n\t"\r
 341                                                 "       move            #14, %a5                                \n\t"\r
 342                                                 "       move            #15, %a6                                \n\t"\r
 343                                                 "                                                                               \n\t"\r
 344                                                 "       cmpi.l          #1, %d0                                 \n\t"\r
 345                                                 "       bne                     reg_test_1_error                \n\t"\r
 346                                                 "       cmpi.l          #2, %d1                                 \n\t"\r
 347                                                 "       bne                     reg_test_1_error                \n\t"\r
 348                                                 "       cmpi.l          #3, %d2                                 \n\t"\r
 349                                                 "       bne                     reg_test_1_error                \n\t"\r
 350                                                 "       cmpi.l          #4, %d3                                 \n\t"\r
 351                                                 "       bne                     reg_test_1_error                \n\t"\r
 352                                                 "       cmpi.l          #5, %d4                                 \n\t"\r
 353                                                 "       bne                     reg_test_1_error                \n\t"\r
 354                                                 "       cmpi.l          #6, %d5                                 \n\t"\r
 355                                                 "       bne                     reg_test_1_error                \n\t"\r
 356                                                 "       cmpi.l          #7, %d6                                 \n\t"\r
 357                                                 "       bne                     reg_test_1_error                \n\t"\r
 358                                                 "       cmpi.l          #8, %d7                                 \n\t"\r
 359                                                 "       bne                     reg_test_1_error                \n\t"\r
 360                                                 "       move            %a0, %d0                                \n\t"\r
 361                                                 "       cmpi.l          #9, %d0                                 \n\t"\r
 362                                                 "       bne                     reg_test_1_error                \n\t"\r
 363                                                 "       move            %a1, %d0                                \n\t"\r
 364                                                 "       cmpi.l          #10, %d0                                \n\t"\r
 365                                                 "       bne                     reg_test_1_error                \n\t"\r
 366                                                 "       move            %a2, %d0                                \n\t"\r
 367                                                 "       cmpi.l          #11, %d0                                \n\t"\r
 368                                                 "       bne                     reg_test_1_error                \n\t"\r
 369                                                 "       move            %a3, %d0                                \n\t"\r
 370                                                 "       cmpi.l          #12, %d0                                \n\t"\r
 371                                                 "       bne                     reg_test_1_error                \n\t"\r
 372                                                 "       move            %a4, %d0                                \n\t"\r
 373                                                 "       cmpi.l          #13, %d0                                \n\t"\r
 374                                                 "       bne                     reg_test_1_error                \n\t"\r
 375                                                 "       move            %a5, %d0                                \n\t"\r
 376                                                 "       cmpi.l          #14, %d0                                \n\t"\r
 377                                                 "       bne                     reg_test_1_error                \n\t"\r
 378                                                 "       move            %a6, %d0                                \n\t"\r
 379                                                 "       cmpi.l          #15, %d0                                \n\t"\r
 380                                                 "       bne                     reg_test_1_error                \n\t"\r
 381                                                 "       movel           ulRegTest1Counter, %d0  \n\t"\r
 382                                                 "       addql           #1, %d0                                 \n\t"\r
 383                                                 "       movel           %d0, ulRegTest1Counter  \n\t"\r
 384                                                 "       bra                     reg_test_1_start                \n\t"\r
 385                                                 "reg_test_1_error:                                              \n\t"\r
 386                                                 "       bra                     reg_test_1_error                \n\t"\r
 387                                         );\r
 388 }\r
 389 /*-----------------------------------------------------------*/\r
 390 \r
 391 static void vRegTest2Task( void *pvParameters )\r
 392 {\r
 393         /* Sanity check - did we receive the parameter expected? */\r
 394         if( pvParameters != &ulRegTest2Counter )\r
 395         {\r
 396                 /* Change here so the check task can detect that an error occurred. */\r
 397                 for( ;; );\r
 398         }\r
 399 \r
 400         /* Set all the registers to known values, then check that each retains its\r
 401         expected value - as described at the top of this file.  If an error is\r
 402         found then the loop counter will no longer be incremented allowing the check\r
 403         task to recognise the error. */\r
 404         asm volatile    (       "reg_test_2_start:                                              \n\t"\r
 405                                                 "       moveq           #10, %d0                                \n\t"\r
 406                                                 "       moveq           #20, %d1                                \n\t"\r
 407                                                 "       moveq           #30, %d2                                \n\t"\r
 408                                                 "       moveq           #40, %d3                                \n\t"\r
 409                                                 "       moveq           #50, %d4                                \n\t"\r
 410                                                 "       moveq           #60, %d5                                \n\t"\r
 411                                                 "       moveq           #70, %d6                                \n\t"\r
 412                                                 "       moveq           #80, %d7                                \n\t"\r
 413                                                 "       move            #90, %a0                                \n\t"\r
 414                                                 "       move            #100, %a1                               \n\t"\r
 415                                                 "       move            #110, %a2                               \n\t"\r
 416                                                 "       move            #120, %a3                               \n\t"\r
 417                                                 "       move            #130, %a4                               \n\t"\r
 418                                                 "       move            #140, %a5                               \n\t"\r
 419                                                 "       move            #150, %a6                               \n\t"\r
 420                                                 "                                                                               \n\t"\r
 421                                                 "       cmpi.l          #10, %d0                                \n\t"\r
 422                                                 "       bne                     reg_test_2_error                \n\t"\r
 423                                                 "       cmpi.l          #20, %d1                                \n\t"\r
 424                                                 "       bne                     reg_test_2_error                \n\t"\r
 425                                                 "       cmpi.l          #30, %d2                                \n\t"\r
 426                                                 "       bne                     reg_test_2_error                \n\t"\r
 427                                                 "       cmpi.l          #40, %d3                                \n\t"\r
 428                                                 "       bne                     reg_test_2_error                \n\t"\r
 429                                                 "       cmpi.l          #50, %d4                                \n\t"\r
 430                                                 "       bne                     reg_test_2_error                \n\t"\r
 431                                                 "       cmpi.l          #60, %d5                                \n\t"\r
 432                                                 "       bne                     reg_test_2_error                \n\t"\r
 433                                                 "       cmpi.l          #70, %d6                                \n\t"\r
 434                                                 "       bne                     reg_test_2_error                \n\t"\r
 435                                                 "       cmpi.l          #80, %d7                                \n\t"\r
 436                                                 "       bne                     reg_test_2_error                \n\t"\r
 437                                                 "       move            %a0, %d0                                \n\t"\r
 438                                                 "       cmpi.l          #90, %d0                                \n\t"\r
 439                                                 "       bne                     reg_test_2_error                \n\t"\r
 440                                                 "       move            %a1, %d0                                \n\t"\r
 441                                                 "       cmpi.l          #100, %d0                               \n\t"\r
 442                                                 "       bne                     reg_test_2_error                \n\t"\r
 443                                                 "       move            %a2, %d0                                \n\t"\r
 444                                                 "       cmpi.l          #110, %d0                               \n\t"\r
 445                                                 "       bne                     reg_test_2_error                \n\t"\r
 446                                                 "       move            %a3, %d0                                \n\t"\r
 447                                                 "       cmpi.l          #120, %d0                               \n\t"\r
 448                                                 "       bne                     reg_test_2_error                \n\t"\r
 449                                                 "       move            %a4, %d0                                \n\t"\r
 450                                                 "       cmpi.l          #130, %d0                               \n\t"\r
 451                                                 "       bne                     reg_test_2_error                \n\t"\r
 452                                                 "       move            %a5, %d0                                \n\t"\r
 453                                                 "       cmpi.l          #140, %d0                               \n\t"\r
 454                                                 "       bne                     reg_test_2_error                \n\t"\r
 455                                                 "       move            %a6, %d0                                \n\t"\r
 456                                                 "       cmpi.l          #150, %d0                               \n\t"\r
 457                                                 "       bne                     reg_test_2_error                \n\t"\r
 458                                                 "       movel           ulRegTest1Counter, %d0  \n\t"\r
 459                                                 "       addql           #1, %d0                                 \n\t"\r
 460                                                 "       movel           %d0, ulRegTest2Counter  \n\t"\r
 461                                                 "       bra                     reg_test_2_start                \n\t"\r
 462                                                 "reg_test_2_error:                                              \n\t"\r
 463                                                 "       bra                     reg_test_2_error                \n\t"\r
 464                                         );\r
 465 }\r
 466 /*-----------------------------------------------------------*/\r
 467 \r