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

   1 ;/*\r
   2 ;    FreeRTOS V6.1.0 - Copyright (C) 2010 Real Time Engineers Ltd.\r
   3 ;\r
   4 ;    ***************************************************************************\r
   5 ;    *                                                                         *\r
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  14 ;    *                                                                         *\r
  15 ;    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *\r
  16 ;    *                  http://www.FreeRTOS.org/Documentation                  *\r
  17 ;    *                                                                         *\r
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  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 exception to the GPL is included to allow you to distribute\r
  31 ;    a combined work that includes FreeRTOS without being obliged to provide the\r
  32 ;    source code for proprietary components outside of the FreeRTOS kernel.\r
  33 ;    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT\r
  34 ;    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or\r
  35 ;    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 ;    http://www.FreeRTOS.org - Documentation, latest information, license and\r
  45 ;    contact details.\r
  46 ;\r
  47 ;    http://www.SafeRTOS.com - A version that is certified for use in safety\r
  48 ;    critical systems.\r
  49 ;\r
  50 ;    http://www.OpenRTOS.com - Commercial support, development, porting,\r
  51 ;    licensing and training services.\r
  52 ;*/\r
  53 \r
  54         IMPORT  ulCriticalNesting               ;\r
  55         IMPORT  pxCurrentTCB                    ;\r
  56 \r
  57 \r
  58         MACRO\r
  59         portRESTORE_CONTEXT\r
  60 \r
  61 \r
  62         LDR             R0, =pxCurrentTCB               ; Set the LR to the task stack.  The location was...\r
  63         LDR             R0, [R0]                                ; ... stored in pxCurrentTCB\r
  64         LDR             LR, [R0]\r
  65 \r
  66         LDR             R0, =ulCriticalNesting  ; The critical nesting depth is the first item on... \r
  67         LDMFD   LR!, {R1}                               ; ...the stack.  Load it into the ulCriticalNesting var.\r
  68         STR             R1, [R0]                                ;\r
  69 \r
  70         LDMFD   LR!, {R0}                               ; Get the SPSR from the stack.\r
  71         MSR             SPSR_cxsf, R0                   ;\r
  72 \r
  73         LDMFD   LR, {R0-R14}^                   ; Restore all system mode registers for the task.\r
  74         NOP                                                             ;\r
  75 \r
  76         LDR             LR, [LR, #+60]                  ; Restore the return address\r
  77 \r
  78                                                                         ; And return - correcting the offset in the LR to obtain ...\r
  79         SUBS    PC, LR, #4                              ; ...the correct address.\r
  80 \r
  81         MEND\r
  82 \r
  83 ; /**********************************************************************/\r
  84 \r
  85         MACRO\r
  86         portSAVE_CONTEXT\r
  87 \r
  88 \r
  89         STMDB   SP!, {R0}                               ; Store R0 first as we need to use it.\r
  90 \r
  91         STMDB   SP,{SP}^                                ; Set R0 to point to the task stack pointer.\r
  92         NOP                                                             ;\r
  93         SUB             SP, SP, #4                              ;\r
  94         LDMIA   SP!,{R0}                                ;\r
  95 \r
  96         STMDB   R0!, {LR}                               ; Push the return address onto the stack.\r
  97         MOV             LR, R0                                  ; Now we have saved LR we can use it instead of R0.\r
  98         LDMIA   SP!, {R0}                               ; Pop R0 so we can save it onto the system mode stack.\r
  99 \r
 100         STMDB   LR,{R0-LR}^                             ; Push all the system mode registers onto the task stack.\r
 101         NOP                                                             ;\r
 102         SUB             LR, LR, #60                             ;\r
 103 \r
 104         MRS             R0, SPSR                                ; Push the SPSR onto the task stack.\r
 105         STMDB   LR!, {R0}                               ;\r
 106 \r
 107         LDR             R0, =ulCriticalNesting  ;\r
 108         LDR             R0, [R0]                                ;\r
 109         STMDB   LR!, {R0}                               ;\r
 110 \r
 111         LDR             R0, =pxCurrentTCB               ; Store the new top of stack for the task.\r
 112         LDR             R1, [R0]                                ;                \r
 113         STR             LR, [R1]                                ;\r
 114         \r
 115         MEND\r
 116         \r
 117         END\r