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

   1 /*\r
   2     FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.\r
   3 \r
   4     FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT \r
   5     http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
   6 \r
   7     ***************************************************************************\r
   8      *                                                                       *\r
   9      *    FreeRTOS tutorial books are available in pdf and paperback.        *\r
  10      *    Complete, revised, and edited pdf reference manuals are also       *\r
  11      *    available.                                                         *\r
  12      *                                                                       *\r
  13      *    Purchasing FreeRTOS documentation will not only help you, by       *\r
  14      *    ensuring you get running as quickly as possible and with an        *\r
  15      *    in-depth knowledge of how to use FreeRTOS, it will also help       *\r
  16      *    the FreeRTOS project to continue with its mission of providing     *\r
  17      *    professional grade, cross platform, de facto standard solutions    *\r
  18      *    for microcontrollers - completely free of charge!                  *\r
  19      *                                                                       *\r
  20      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *\r
  21      *                                                                       *\r
  22      *    Thank you for using FreeRTOS, and thank you for your support!      *\r
  23      *                                                                       *\r
  24     ***************************************************************************\r
  25 \r
  26 \r
  27     This file is part of the FreeRTOS distribution.\r
  28 \r
  29     FreeRTOS is free software; you can redistribute it and/or modify it under\r
  30     the terms of the GNU General Public License (version 2) as published by the\r
  31     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.\r
  32     >>>NOTE<<< The modification to the GPL is included to allow you to\r
  33     distribute a combined work that includes FreeRTOS without being obliged to\r
  34     provide the source code for proprietary components outside of the FreeRTOS\r
  35     kernel.  FreeRTOS is distributed in the hope that it will be useful, but\r
  36     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY\r
  37     or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
  38     more details. You should have received a copy of the GNU General Public\r
  39     License and the FreeRTOS license exception along with FreeRTOS; if not it\r
  40     can be viewed here: http://www.freertos.org/a00114.html and also obtained\r
  41     by writing to Richard Barry, contact details for whom are available on the\r
  42     FreeRTOS WEB site.\r
  43 \r
  44     1 tab == 4 spaces!\r
  45     \r
  46     ***************************************************************************\r
  47      *                                                                       *\r
  48      *    Having a problem?  Start by reading the FAQ "My application does   *\r
  49      *    not run, what could be wrong?"                                     *\r
  50      *                                                                       *\r
  51      *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
  52      *                                                                       *\r
  53     ***************************************************************************\r
  54 \r
  55     \r
  56     http://www.FreeRTOS.org - Documentation, training, latest versions, license \r
  57     and contact details.  \r
  58     \r
  59     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
  60     including FreeRTOS+Trace - an indispensable productivity tool.\r
  61 \r
  62     Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell \r
  63     the code with commercial support, indemnification, and middleware, under \r
  64     the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also\r
  65     provide a safety engineered and independently SIL3 certified version under \r
  66     the SafeRTOS brand: http://www.SafeRTOS.com.\r
  67 */\r
  68 \r
  69 #include <FreeRTOSConfig.h>\r
  70 \r
  71 /* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is\r
  72 defined.  The value zero should also ensure backward compatibility.\r
  73 FreeRTOS.org versions prior to V4.3.0 did not include this definition. */\r
  74 #ifndef configKERNEL_INTERRUPT_PRIORITY\r
  75         #define configKERNEL_INTERRUPT_PRIORITY 0\r
  76 #endif\r
  77 \r
  78         \r
  79         RSEG    CODE:CODE(2)\r
  80         thumb\r
  81 \r
  82         EXTERN vPortYieldFromISR\r
  83         EXTERN pxCurrentTCB\r
  84         EXTERN vTaskSwitchContext\r
  85 \r
  86         PUBLIC vSetMSP\r
  87         PUBLIC xPortPendSVHandler\r
  88         PUBLIC vPortSVCHandler\r
  89         PUBLIC vPortStartFirstTask\r
  90 \r
  91 \r
  92 /*-----------------------------------------------------------*/\r
  93 \r
  94 vSetMSP\r
  95         msr msp, r0\r
  96         bx lr\r
  97         \r
  98 /*-----------------------------------------------------------*/\r
  99 \r
 100 xPortPendSVHandler:\r
 101         mrs r0, psp                                                     \r
 102                                                                                         \r
 103         ldr     r3, =pxCurrentTCB       /* Get the location of the current TCB. */\r
 104         ldr     r2, [r3]                                                \r
 105                                                                                         \r
 106         subs r0, r0, #32                /* Make space for the remaining low registers. */\r
 107         str r0, [r2]                    /* Save the new top of stack. */\r
 108         stmia r0!, {r4-r7}              /* Store the low registers that are not saved automatically. */\r
 109         mov r4, r8                              /* Store the high registers. */\r
 110         mov r5, r9                                                      \r
 111         mov r6, r10                                                     \r
 112         mov r7, r11                                                     \r
 113         stmia r0!, {r4-r7}                      \r
 114                                                                                         \r
 115         push {r3, r14}                                          \r
 116         cpsid i                                                         \r
 117         bl vTaskSwitchContext                           \r
 118         cpsie i                                                         \r
 119         pop {r2, r3}                    /* lr goes in r3. r2 now holds tcb pointer. */\r
 120                                                                                         \r
 121         ldr r1, [r2]                                            \r
 122         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 123         adds r0, r0, #16                /* Move to the high registers. */\r
 124         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 125         mov r8, r4                                                      \r
 126         mov r9, r5                                                      \r
 127         mov r10, r6                                                     \r
 128         mov r11, r7                                                     \r
 129                                                                                         \r
 130         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 131                                                                                         \r
 132         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 133         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 134                                                                                         \r
 135         bx r3                                                           \r
 136 \r
 137 /*-----------------------------------------------------------*/\r
 138 \r
 139 vPortSVCHandler;\r
 140         ldr     r3, =pxCurrentTCB       /* Restore the context. */\r
 141         ldr r1, [r3]                    /* Get the pxCurrentTCB address. */\r
 142         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 143         adds r0, r0, #16                /* Move to the high registers. */\r
 144         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 145         mov r8, r4                                              \r
 146         mov r9, r5                                              \r
 147         mov r10, r6                                             \r
 148         mov r11, r7                                             \r
 149                                                                                 \r
 150         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 151                                                                                 \r
 152         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 153         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 154         mov r1, r14                             /* OR R14 with 0x0d. */\r
 155         movs r0, #0x0d                                  \r
 156         orrs r1, r0                                             \r
 157         bx r1                                                   \r
 158 \r
 159 /*-----------------------------------------------------------*/\r
 160 \r
 161 vPortStartFirstTask\r
 162         movs r0, #0x00                  /* Locate the top of stack. */\r
 163         ldr r0, [r0]            \r
 164         msr msp, r0                             /* Set the msp back to the start of the stack. */\r
 165         cpsie i                                 /* Globally enable interrupts. */\r
 166         svc 0                                   /* System call to start first task. */\r
 167         nop                             \r
 168         \r
 169         END\r
 170