git.sur5r.net Git - freertos/blob - FreeRTOS/Source/portable/IAR/ARM_CM0/portasm.s

   1 /*\r
   2     FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.\r
   3         \r
   4 \r
   5     ***************************************************************************\r
   6      *                                                                       *\r
   7      *    FreeRTOS tutorial books are available in pdf and paperback.        *\r
   8      *    Complete, revised, and edited pdf reference manuals are also       *\r
   9      *    available.                                                         *\r
  10      *                                                                       *\r
  11      *    Purchasing FreeRTOS documentation will not only help you, by       *\r
  12      *    ensuring you get running as quickly as possible and with an        *\r
  13      *    in-depth knowledge of how to use FreeRTOS, it will also help       *\r
  14      *    the FreeRTOS project to continue with its mission of providing     *\r
  15      *    professional grade, cross platform, de facto standard solutions    *\r
  16      *    for microcontrollers - completely free of charge!                  *\r
  17      *                                                                       *\r
  18      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *\r
  19      *                                                                       *\r
  20      *    Thank you for using FreeRTOS, and thank you for your support!      *\r
  21      *                                                                       *\r
  22     ***************************************************************************\r
  23 \r
  24 \r
  25     This file is part of the FreeRTOS distribution.\r
  26 \r
  27     FreeRTOS is free software; you can redistribute it and/or modify it under\r
  28     the terms of the GNU General Public License (version 2) as published by the\r
  29     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.\r
  30     >>>NOTE<<< The modification to the GPL is included to allow you to\r
  31     distribute a combined work that includes FreeRTOS without being obliged to\r
  32     provide the source code for proprietary components outside of the FreeRTOS\r
  33     kernel.  FreeRTOS is distributed in the hope that it will be useful, but\r
  34     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY\r
  35     or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
  36     more details. You should have received a copy of the GNU General Public\r
  37     License and the FreeRTOS license exception along with FreeRTOS; if not it\r
  38     can be viewed here: http://www.freertos.org/a00114.html and also obtained\r
  39     by writing to Richard Barry, contact details for whom are available on the\r
  40     FreeRTOS WEB site.\r
  41 \r
  42     1 tab == 4 spaces!\r
  43     \r
  44     ***************************************************************************\r
  45      *                                                                       *\r
  46      *    Having a problem?  Start by reading the FAQ "My application does   *\r
  47      *    not run, what could be wrong?                                      *\r
  48      *                                                                       *\r
  49      *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
  50      *                                                                       *\r
  51     ***************************************************************************\r
  52 \r
  53     \r
  54     http://www.FreeRTOS.org - Documentation, training, latest information, \r
  55     license and contact details.\r
  56     \r
  57     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
  58     including FreeRTOS+Trace - an indispensable productivity tool.\r
  59 \r
  60     Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell \r
  61     the code with commercial support, indemnification, and middleware, under \r
  62     the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also\r
  63     provide a safety engineered and independently SIL3 certified version under \r
  64     the SafeRTOS brand: http://www.SafeRTOS.com.\r
  65 */\r
  66 \r
  67 #include <FreeRTOSConfig.h>\r
  68 \r
  69 /* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is\r
  70 defined.  The value zero should also ensure backward compatibility.\r
  71 FreeRTOS.org versions prior to V4.3.0 did not include this definition. */\r
  72 #ifndef configKERNEL_INTERRUPT_PRIORITY\r
  73         #define configKERNEL_INTERRUPT_PRIORITY 0\r
  74 #endif\r
  75 \r
  76         \r
  77         RSEG    CODE:CODE(2)\r
  78         thumb\r
  79 \r
  80         EXTERN vPortYieldFromISR\r
  81         EXTERN pxCurrentTCB\r
  82         EXTERN vTaskSwitchContext\r
  83 \r
  84         PUBLIC vSetMSP\r
  85         PUBLIC xPortPendSVHandler\r
  86         PUBLIC vPortSVCHandler\r
  87         PUBLIC vPortStartFirstTask\r
  88 \r
  89 \r
  90 /*-----------------------------------------------------------*/\r
  91 \r
  92 vSetMSP\r
  93         msr msp, r0\r
  94         bx lr\r
  95         \r
  96 /*-----------------------------------------------------------*/\r
  97 \r
  98 xPortPendSVHandler:\r
  99         mrs r0, psp                                                     \r
 100                                                                                         \r
 101         ldr     r3, =pxCurrentTCB       /* Get the location of the current TCB. */\r
 102         ldr     r2, [r3]                                                \r
 103                                                                                         \r
 104         subs r0, r0, #32                /* Make space for the remaining low registers. */\r
 105         str r0, [r2]                    /* Save the new top of stack. */\r
 106         stmia r0!, {r4-r7}              /* Store the low registers that are not saved automatically. */\r
 107         mov r4, r8                              /* Store the high registers. */\r
 108         mov r5, r9                                                      \r
 109         mov r6, r10                                                     \r
 110         mov r7, r11                                                     \r
 111         stmia r0!, {r4-r7}                      \r
 112                                                                                         \r
 113         push {r3, r14}                                          \r
 114         cpsid i                                                         \r
 115         bl vTaskSwitchContext                           \r
 116         cpsie i                                                         \r
 117         pop {r2, r3}                    /* lr goes in r3. r2 now holds tcb pointer. */\r
 118                                                                                         \r
 119         ldr r1, [r2]                                            \r
 120         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 121         adds r0, r0, #16                /* Move to the high registers. */\r
 122         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 123         mov r8, r4                                                      \r
 124         mov r9, r5                                                      \r
 125         mov r10, r6                                                     \r
 126         mov r11, r7                                                     \r
 127                                                                                         \r
 128         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 129                                                                                         \r
 130         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 131         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 132                                                                                         \r
 133         bx r3                                                           \r
 134 \r
 135 /*-----------------------------------------------------------*/\r
 136 \r
 137 vPortSVCHandler;\r
 138         ldr     r3, =pxCurrentTCB       /* Restore the context. */\r
 139         ldr r1, [r3]                    /* Get the pxCurrentTCB address. */\r
 140         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 141         adds r0, r0, #16                /* Move to the high registers. */\r
 142         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 143         mov r8, r4                                              \r
 144         mov r9, r5                                              \r
 145         mov r10, r6                                             \r
 146         mov r11, r7                                             \r
 147                                                                                 \r
 148         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 149                                                                                 \r
 150         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 151         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 152         mov r1, r14                             /* OR R14 with 0x0d. */\r
 153         movs r0, #0x0d                                  \r
 154         orrs r1, r0                                             \r
 155         bx r1                                                   \r
 156 \r
 157 /*-----------------------------------------------------------*/\r
 158 \r
 159 vPortStartFirstTask\r
 160         movs r0, #0x00                  /* Locate the top of stack. */\r
 161         ldr r0, [r0]            \r
 162         msr msp, r0                             /* Set the msp back to the start of the stack. */\r
 163         cpsie i                                 /* Globally enable interrupts. */\r
 164         svc 0                                   /* System call to start first task. */\r
 165         nop                             \r
 166         \r
 167         END\r
 168