git.sur5r.net Git - freertos/blob - Source/portable/RVDS/ARM7_LPC21xx/portmacro.inc

   1 ;/*\r
   2 ;       FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 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 it \r
   7 ;       under the terms of the GNU General Public License (version 2) as published\r
   8 ;       by the Free Software Foundation and modified by the FreeRTOS exception.\r
   9 ;\r
  10 ;       FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT\r
  11 ;       ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or \r
  12 ;       FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for \r
  13 ;       more details.\r
  14 ;\r
  15 ;       You should have received a copy of the GNU General Public License along \r
  16 ;       with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 \r
  17 ;       Temple Place, Suite 330, Boston, MA  02111-1307  USA.\r
  18 ;\r
  19 ;       A special exception to the GPL is included to allow you to distribute a \r
  20 ;       combined work that includes FreeRTOS.org without being obliged to provide\r
  21 ;       the source code for any proprietary components.  See the licensing section\r
  22 ;       of http://www.FreeRTOS.org for full details.\r
  23 ;\r
  24 ;\r
  25 ;       ***************************************************************************\r
  26 ;       *                                                                         *\r
  27 ;       * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *\r
  28 ;       *                                                                         *\r
  29 ;       * This is a concise, step by step, 'hands on' guide that describes both   *\r
  30 ;       * general multitasking concepts and FreeRTOS specifics. It presents and   *\r
  31 ;       * explains numerous examples that are written using the FreeRTOS API.     *\r
  32 ;       * Full source code for all the examples is provided in an accompanying    *\r
  33 ;       * .zip file.                                                              *\r
  34 ;       *                                                                         *\r
  35 ;       ***************************************************************************\r
  36 ;\r
  37 ;       1 tab == 4 spaces!\r
  38 ;\r
  39 ;       Please ensure to read the configuration and relevant port sections of the\r
  40 ;       online documentation.\r
  41 ;\r
  42 ;       http://www.FreeRTOS.org - Documentation, latest information, license and\r
  43 ;       contact details.\r
  44 ;\r
  45 ;       http://www.SafeRTOS.com - A version that is certified for use in safety\r
  46 ;       critical systems.\r
  47 ;\r
  48 ;       http://www.OpenRTOS.com - Commercial support, development, porting,\r
  49 ;       licensing and training services.\r
  50 ;*/\r
  51 \r
  52         IMPORT  ulCriticalNesting               ;\r
  53         IMPORT  pxCurrentTCB                    ;\r
  54 \r
  55 \r
  56         MACRO\r
  57         portRESTORE_CONTEXT\r
  58 \r
  59 \r
  60         LDR             R0, =pxCurrentTCB               ; Set the LR to the task stack.  The location was...\r
  61         LDR             R0, [R0]                                ; ... stored in pxCurrentTCB\r
  62         LDR             LR, [R0]\r
  63 \r
  64         LDR             R0, =ulCriticalNesting  ; The critical nesting depth is the first item on... \r
  65         LDMFD   LR!, {R1}                               ; ...the stack.  Load it into the ulCriticalNesting var.\r
  66         STR             R1, [R0]                                ;\r
  67 \r
  68         LDMFD   LR!, {R0}                               ; Get the SPSR from the stack.\r
  69         MSR             SPSR_cxsf, R0                   ;\r
  70 \r
  71         LDMFD   LR, {R0-R14}^                   ; Restore all system mode registers for the task.\r
  72         NOP                                                             ;\r
  73 \r
  74         LDR             LR, [LR, #+60]                  ; Restore the return address\r
  75 \r
  76                                                                         ; And return - correcting the offset in the LR to obtain ...\r
  77         SUBS    PC, LR, #4                              ; ...the correct address.\r
  78 \r
  79         MEND\r
  80 \r
  81 ; /**********************************************************************/\r
  82 \r
  83         MACRO\r
  84         portSAVE_CONTEXT\r
  85 \r
  86 \r
  87         STMDB   SP!, {R0}                               ; Store R0 first as we need to use it.\r
  88 \r
  89         STMDB   SP,{SP}^                                ; Set R0 to point to the task stack pointer.\r
  90         NOP                                                             ;\r
  91         SUB             SP, SP, #4                              ;\r
  92         LDMIA   SP!,{R0}                                ;\r
  93 \r
  94         STMDB   R0!, {LR}                               ; Push the return address onto the stack.\r
  95         MOV             LR, R0                                  ; Now we have saved LR we can use it instead of R0.\r
  96         LDMIA   SP!, {R0}                               ; Pop R0 so we can save it onto the system mode stack.\r
  97 \r
  98         STMDB   LR,{R0-LR}^                             ; Push all the system mode registers onto the task stack.\r
  99         NOP                                                             ;\r
 100         SUB             LR, LR, #60                             ;\r
 101 \r
 102         MRS             R0, SPSR                                ; Push the SPSR onto the task stack.\r
 103         STMDB   LR!, {R0}                               ;\r
 104 \r
 105         LDR             R0, =ulCriticalNesting  ;\r
 106         LDR             R0, [R0]                                ;\r
 107         STMDB   LR!, {R0}                               ;\r
 108 \r
 109         LDR             R0, =pxCurrentTCB               ; Store the new top of stack for the task.\r
 110         LDR             R1, [R0]                                ;                \r
 111         STR             LR, [R1]                                ;\r
 112         \r
 113         MEND\r
 114         \r
 115         END\r