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

   1 /*\r
   2     FreeRTOS V7.4.2 - Copyright (C) 2013 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 \r
  33     >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to\r
  34     distribute a combined work that includes FreeRTOS without being obliged to\r
  35     provide the source code for proprietary components outside of the FreeRTOS\r
  36     kernel.\r
  37 \r
  38     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY\r
  39     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
  40     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more\r
  41     details. You should have received a copy of the GNU General Public License\r
  42     and the FreeRTOS license exception along with FreeRTOS; if not it can be\r
  43     viewed here: http://www.freertos.org/a00114.html and also obtained by\r
  44     writing to Real Time Engineers Ltd., contact details for whom are available\r
  45     on the FreeRTOS WEB site.\r
  46 \r
  47     1 tab == 4 spaces!\r
  48 \r
  49     ***************************************************************************\r
  50      *                                                                       *\r
  51      *    Having a problem?  Start by reading the FAQ "My application does   *\r
  52      *    not run, what could be wrong?"                                     *\r
  53      *                                                                       *\r
  54      *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
  55      *                                                                       *\r
  56     ***************************************************************************\r
  57 \r
  58 \r
  59     http://www.FreeRTOS.org - Documentation, books, training, latest versions, \r
  60     license and Real Time Engineers Ltd. contact details.\r
  61 \r
  62     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
  63     including FreeRTOS+Trace - an indispensable productivity tool, and our new\r
  64     fully thread aware and reentrant UDP/IP stack.\r
  65 \r
  66     http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High \r
  67     Integrity Systems, who sell the code with commercial support, \r
  68     indemnification and middleware, under the OpenRTOS brand.\r
  69     \r
  70     http://www.SafeRTOS.com - High Integrity Systems also provide a safety \r
  71     engineered and independently SIL3 certified version for use in safety and \r
  72     mission critical applications that require provable dependability.\r
  73 */\r
  74 \r
  75 #include <FreeRTOSConfig.h>\r
  76 \r
  77 /* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is\r
  78 defined.  The value zero should also ensure backward compatibility.\r
  79 FreeRTOS.org versions prior to V4.3.0 did not include this definition. */\r
  80 #ifndef configKERNEL_INTERRUPT_PRIORITY\r
  81         #define configKERNEL_INTERRUPT_PRIORITY 0\r
  82 #endif\r
  83 \r
  84         \r
  85         RSEG    CODE:CODE(2)\r
  86         thumb\r
  87 \r
  88         EXTERN vPortYieldFromISR\r
  89         EXTERN pxCurrentTCB\r
  90         EXTERN vTaskSwitchContext\r
  91 \r
  92         PUBLIC vSetMSP\r
  93         PUBLIC xPortPendSVHandler\r
  94         PUBLIC vPortSVCHandler\r
  95         PUBLIC vPortStartFirstTask\r
  96 \r
  97 \r
  98 /*-----------------------------------------------------------*/\r
  99 \r
 100 vSetMSP\r
 101         msr msp, r0\r
 102         bx lr\r
 103         \r
 104 /*-----------------------------------------------------------*/\r
 105 \r
 106 xPortPendSVHandler:\r
 107         mrs r0, psp                                                     \r
 108                                                                                         \r
 109         ldr     r3, =pxCurrentTCB       /* Get the location of the current TCB. */\r
 110         ldr     r2, [r3]                                                \r
 111                                                                                         \r
 112         subs r0, r0, #32                /* Make space for the remaining low registers. */\r
 113         str r0, [r2]                    /* Save the new top of stack. */\r
 114         stmia r0!, {r4-r7}              /* Store the low registers that are not saved automatically. */\r
 115         mov r4, r8                              /* Store the high registers. */\r
 116         mov r5, r9                                                      \r
 117         mov r6, r10                                                     \r
 118         mov r7, r11                                                     \r
 119         stmia r0!, {r4-r7}                      \r
 120                                                                                         \r
 121         push {r3, r14}                                          \r
 122         cpsid i                                                         \r
 123         bl vTaskSwitchContext                           \r
 124         cpsie i                                                         \r
 125         pop {r2, r3}                    /* lr goes in r3. r2 now holds tcb pointer. */\r
 126                                                                                         \r
 127         ldr r1, [r2]                                            \r
 128         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 129         adds r0, r0, #16                /* Move to the high registers. */\r
 130         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 131         mov r8, r4                                                      \r
 132         mov r9, r5                                                      \r
 133         mov r10, r6                                                     \r
 134         mov r11, r7                                                     \r
 135                                                                                         \r
 136         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 137                                                                                         \r
 138         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 139         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 140                                                                                         \r
 141         bx r3                                                           \r
 142 \r
 143 /*-----------------------------------------------------------*/\r
 144 \r
 145 vPortSVCHandler;\r
 146         ldr     r3, =pxCurrentTCB       /* Restore the context. */\r
 147         ldr r1, [r3]                    /* Get the pxCurrentTCB address. */\r
 148         ldr r0, [r1]                    /* The first item in pxCurrentTCB is the task top of stack. */\r
 149         adds r0, r0, #16                /* Move to the high registers. */\r
 150         ldmia r0!, {r4-r7}              /* Pop the high registers. */\r
 151         mov r8, r4                                              \r
 152         mov r9, r5                                              \r
 153         mov r10, r6                                             \r
 154         mov r11, r7                                             \r
 155                                                                                 \r
 156         msr psp, r0                             /* Remember the new top of stack for the task. */\r
 157                                                                                 \r
 158         subs r0, r0, #32                /* Go back for the low registers that are not automatically restored. */\r
 159         ldmia r0!, {r4-r7}              /* Pop low registers.  */\r
 160         mov r1, r14                             /* OR R14 with 0x0d. */\r
 161         movs r0, #0x0d                                  \r
 162         orrs r1, r0                                             \r
 163         bx r1                                                   \r
 164 \r
 165 /*-----------------------------------------------------------*/\r
 166 \r
 167 vPortStartFirstTask\r
 168         movs r0, #0x00                  /* Locate the top of stack. */\r
 169         ldr r0, [r0]            \r
 170         msr msp, r0                             /* Set the msp back to the start of the stack. */\r
 171         cpsie i                                 /* Globally enable interrupts. */\r
 172         svc 0                                   /* System call to start first task. */\r
 173         nop                             \r
 174         \r
 175         END\r
 176