begriffs open source - freertos/blob - Source/portable/oWatcom/16BitDOS/common/portasm.h

   1 /*\r
   2         FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section \r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26     ***************************************************************************\r
  27     ***************************************************************************\r
  28     *                                                                         *\r
  29     * SAVE TIME AND MONEY!  We can port FreeRTOS.org to your own hardware,    *\r
  30     * and even write all or part of your application on your behalf.          *\r
  31     * See http://www.OpenRTOS.com for details of the services we provide to   *\r
  32     * expedite your project.                                                  *\r
  33     *                                                                         *\r
  34     ***************************************************************************\r
  35     ***************************************************************************\r
  36 \r
  37         Please ensure to read the configuration and relevant port sections of the\r
  38         online documentation.\r
  39 \r
  40         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  41         contact details.\r
  42 \r
  43         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  44         critical systems.\r
  45 \r
  46         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  47         licensing and training services.\r
  48 */\r
  49 \r
  50 typedef void tskTCB;\r
  51 extern volatile tskTCB * volatile pxCurrentTCB;\r
  52 extern void vTaskSwitchContext( void );\r
  53 \r
  54 /* \r
  55  * Saves the stack pointer for one task into its TCB, calls \r
  56  * vTaskSwitchContext() to update the TCB being used, then restores the stack \r
  57  * from the new TCB read to run the task. \r
  58  */\r
  59 void portSWITCH_CONTEXT( void );\r
  60 \r
  61 /*\r
  62  * Load the stack pointer from the TCB of the task which is going to be first\r
  63  * to execute.  Then force an IRET so the registers and IP are popped off the\r
  64  * stack.\r
  65  */\r
  66 void portFIRST_CONTEXT( void );\r
  67 \r
  68 /* There are slightly different versions depending on whether you are building\r
  69 to include debugger information.  If debugger information is used then there\r
  70 are a couple of extra bytes left of the ISR stack (presumably for use by the\r
  71 debugger).  The true stack pointer is then stored in the bp register.  We add\r
  72 2 to the stack pointer to remove the extra bytes before we restore our context. */\r
  73 \r
  74 #ifdef DEBUG_BUILD\r
  75 \r
  76         #pragma aux portSWITCH_CONTEXT =        "mov    ax, seg pxCurrentTCB"                                                                                                           \\r
  77                                                                                 "mov    ds, ax"                                                                                                                                         \\r
  78                                                                                 "les    bx, pxCurrentTCB"                       /* Save the stack pointer into the TCB. */              \\r
  79                                                                                 "mov    es:0x2[ bx ], ss"                                                                                                                       \\r
  80                                                                                 "mov    es:[ bx ], sp"                                                                                                                          \\r
  81                                                                                 "call   vTaskSwitchContext"                     /* Perform the switch. */                                               \\r
  82                                                                                 "mov    ax, seg pxCurrentTCB"           /* Restore the stack pointer from the TCB. */   \\r
  83                                                                                 "mov    ds, ax"                                                                                                                                         \\r
  84                                                                                 "les    bx, dword ptr pxCurrentTCB"                                                                                                     \\r
  85                                                                                 "mov    ss, es:[ bx + 2 ]"                                                                                                                      \\r
  86                                                                                 "mov    sp, es:[ bx ]"                                                                                                                          \\r
  87                                                                                 "mov    bp, sp"                                         /* Prepair the bp register for the restoration of the SP in the compiler generated portion of the ISR */        \\r
  88                                                                                 "add    bp, 0x0002"\r
  89 \r
  90                                                                                 \r
  91 \r
  92         #pragma aux portFIRST_CONTEXT =         "mov    ax, seg pxCurrentTCB"                   \\r
  93                                                                                 "mov    ds, ax"                                                 \\r
  94                                                                                 "les    bx, dword ptr pxCurrentTCB"             \\r
  95                                                                                 "mov    ss, es:[ bx + 2 ]"                              \\r
  96                                                                                 "mov    sp, es:[ bx ]"                                  \\r
  97                                                                                 "add    sp, 0x0002"                                             /* Remove the extra bytes that exist in debug builds before restoring the context. */ \\r
  98                                                                                 "pop    ax"                                                             \\r
  99                                                                                 "pop    ax"                                                             \\r
 100                                                                                 "pop    es"                                                             \\r
 101                                                                                 "pop    ds"                                                             \\r
 102                                                                                 "popa"                                                                  \\r
 103                                                                                 "iret"                                                                  \r
 104 #else\r
 105 \r
 106         #pragma aux portSWITCH_CONTEXT =        "mov    ax, seg pxCurrentTCB"                                                                                                           \\r
 107                                                                                 "mov    ds, ax"                                                                                                                                         \\r
 108                                                                                 "les    bx, pxCurrentTCB"                       /* Save the stack pointer into the TCB. */              \\r
 109                                                                                 "mov    es:0x2[ bx ], ss"                                                                                                                       \\r
 110                                                                                 "mov    es:[ bx ], sp"                                                                                                                          \\r
 111                                                                                 "call   vTaskSwitchContext"                     /* Perform the switch. */                                               \\r
 112                                                                                 "mov    ax, seg pxCurrentTCB"           /* Restore the stack pointer from the TCB. */   \\r
 113                                                                                 "mov    ds, ax"                                                                                                                                         \\r
 114                                                                                 "les    bx, dword ptr pxCurrentTCB"                                                                                                     \\r
 115                                                                                 "mov    ss, es:[ bx + 2 ]"                                                                                                                      \\r
 116                                                                                 "mov    sp, es:[ bx ]"\r
 117                                                                                 \r
 118 \r
 119         #pragma aux portFIRST_CONTEXT =         "mov    ax, seg pxCurrentTCB"                   \\r
 120                                                                                 "mov    ds, ax"                                                 \\r
 121                                                                                 "les    bx, dword ptr pxCurrentTCB"             \\r
 122                                                                                 "mov    ss, es:[ bx + 2 ]"                              \\r
 123                                                                                 "mov    sp, es:[ bx ]"                                  \\r
 124                                                                                 "pop    ax"                                                             \\r
 125                                                                                 "pop    ax"                                                             \\r
 126                                                                                 "pop    es"                                                             \\r
 127                                                                                 "pop    ds"                                                             \\r
 128                                                                                 "popa"                                                                  \\r
 129                                                                                 "iret"                                                                  \r
 130 #endif\r
 131 \r
 132 \r