1 | .. SPDX-License-Identifier: CC-BY-SA-4.0 |
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2 | |
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3 | .. Copyright (C) 2020, 2021 embedded brains GmbH (http://www.embedded-brains.de) |
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4 | .. Copyright (C) 1988, 2008 On-Line Applications Research Corporation (OAR) |
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5 | |
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6 | .. This file is part of the RTEMS quality process and was automatically |
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7 | .. generated. If you find something that needs to be fixed or |
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8 | .. worded better please post a report or patch to an RTEMS mailing list |
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9 | .. or raise a bug report: |
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10 | .. |
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11 | .. https://www.rtems.org/bugs.html |
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12 | .. |
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13 | .. For information on updating and regenerating please refer to the How-To |
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14 | .. section in the Software Requirements Engineering chapter of the |
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15 | .. RTEMS Software Engineering manual. The manual is provided as a part of |
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16 | .. a release. For development sources please refer to the online |
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17 | .. documentation at: |
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18 | .. |
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19 | .. https://docs.rtems.org |
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20 | |
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21 | .. Generated from spec:/acfg/if/group-general |
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22 | |
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23 | General System Configuration |
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24 | ============================ |
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25 | |
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26 | This section describes general system configuration options. |
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27 | |
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28 | .. Generated from spec:/acfg/if/dirty-memory |
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29 | |
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30 | .. raw:: latex |
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31 | |
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32 | \clearpage |
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33 | |
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34 | .. index:: CONFIGURE_DIRTY_MEMORY |
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35 | |
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36 | .. _CONFIGURE_DIRTY_MEMORY: |
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37 | |
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38 | CONFIGURE_DIRTY_MEMORY |
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39 | ---------------------- |
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40 | |
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41 | .. rubric:: CONSTANT: |
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42 | |
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43 | ``CONFIGURE_DIRTY_MEMORY`` |
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44 | |
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45 | .. rubric:: OPTION TYPE: |
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46 | |
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47 | This configuration option is a boolean feature define. |
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48 | |
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49 | .. rubric:: DEFAULT CONFIGURATION: |
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50 | |
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51 | If this configuration option is undefined, then the described feature is not |
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52 | enabled. |
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53 | |
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54 | .. rubric:: DESCRIPTION: |
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55 | |
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56 | In case this configuration option is defined, then the memory areas used for |
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57 | the RTEMS Workspace and the C Program Heap are dirtied with a ``0xCF`` byte |
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58 | pattern during system initialization. |
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59 | |
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60 | .. rubric:: NOTES: |
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61 | |
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62 | Dirtying memory can add significantly to system initialization time. It may |
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63 | assist in finding code that incorrectly assumes the contents of free memory |
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64 | areas is cleared to zero during system initialization. In case |
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65 | :ref:`CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY` is also defined, then the |
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66 | memory is first dirtied and then zeroed. |
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67 | |
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68 | See also :ref:`CONFIGURE_MALLOC_DIRTY`. |
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69 | |
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70 | .. Generated from spec:/acfg/if/disable-newlib-reentrancy |
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71 | |
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72 | .. raw:: latex |
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73 | |
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74 | \clearpage |
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75 | |
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76 | .. index:: CONFIGURE_DISABLE_NEWLIB_REENTRANCY |
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77 | |
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78 | .. _CONFIGURE_DISABLE_NEWLIB_REENTRANCY: |
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79 | |
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80 | CONFIGURE_DISABLE_NEWLIB_REENTRANCY |
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81 | ----------------------------------- |
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82 | |
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83 | .. rubric:: CONSTANT: |
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84 | |
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85 | ``CONFIGURE_DISABLE_NEWLIB_REENTRANCY`` |
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86 | |
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87 | .. rubric:: OPTION TYPE: |
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88 | |
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89 | This configuration option is a boolean feature define. |
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90 | |
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91 | .. rubric:: DEFAULT CONFIGURATION: |
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92 | |
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93 | If this configuration option is undefined, then the described feature is not |
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94 | enabled. |
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95 | |
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96 | .. rubric:: DESCRIPTION: |
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97 | |
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98 | In case this configuration option is defined, then the Newlib reentrancy |
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99 | support per thread is disabled and a global reentrancy structure is used. |
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100 | |
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101 | .. rubric:: NOTES: |
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102 | |
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103 | You can enable this option to reduce the size of the :term:`TCB`. Use this |
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104 | option with care, since it can lead to race conditions and undefined system |
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105 | behaviour. For example, :c:macro:`errno` is no longer a thread-local |
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106 | variable if this option is enabled. |
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107 | |
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108 | .. Generated from spec:/acfg/if/executive-ram-size |
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109 | |
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110 | .. raw:: latex |
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111 | |
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112 | \clearpage |
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113 | |
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114 | .. index:: CONFIGURE_EXECUTIVE_RAM_SIZE |
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115 | |
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116 | .. _CONFIGURE_EXECUTIVE_RAM_SIZE: |
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117 | |
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118 | CONFIGURE_EXECUTIVE_RAM_SIZE |
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119 | ---------------------------- |
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120 | |
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121 | .. rubric:: CONSTANT: |
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122 | |
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123 | ``CONFIGURE_EXECUTIVE_RAM_SIZE`` |
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124 | |
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125 | .. rubric:: OPTION TYPE: |
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126 | |
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127 | This configuration option is an integer define. |
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128 | |
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129 | .. rubric:: DEFAULT VALUE: |
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130 | |
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131 | If this configuration option is undefined, then the RTEMS Workspace and task |
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132 | stack space size is calculated by ``<rtems/confdefs.h>`` based on the values |
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133 | configuration options. |
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134 | |
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135 | .. rubric:: DESCRIPTION: |
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136 | |
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137 | The value of this configuration option defines the RTEMS Workspace size in |
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138 | bytes. |
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139 | |
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140 | .. rubric:: NOTES: |
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141 | |
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142 | This is an advanced configuration option. Use it only if you know exactly |
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143 | what you are doing. |
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144 | |
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145 | .. rubric:: CONSTRAINTS: |
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146 | |
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147 | The following constraints apply to this configuration option: |
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148 | |
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149 | * The value of the configuration option shall be greater than or equal to zero. |
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150 | |
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151 | * The value of the configuration option shall be less than or equal to |
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152 | `UINTPTR_MAX <https://en.cppreference.com/w/c/types/integer>`_. |
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153 | |
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154 | * The value of the configuration option shall be less than or equal to a |
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155 | BSP-specific and application-specific value which depends on the size of the |
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156 | memory available to the application. |
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157 | |
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158 | .. Generated from spec:/acfg/if/extra-task-stacks |
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159 | |
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160 | .. raw:: latex |
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161 | |
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162 | \clearpage |
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163 | |
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164 | .. index:: CONFIGURE_EXTRA_TASK_STACKS |
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165 | .. index:: memory for task tasks |
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166 | |
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167 | .. _CONFIGURE_EXTRA_TASK_STACKS: |
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168 | |
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169 | CONFIGURE_EXTRA_TASK_STACKS |
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170 | --------------------------- |
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171 | |
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172 | .. rubric:: CONSTANT: |
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173 | |
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174 | ``CONFIGURE_EXTRA_TASK_STACKS`` |
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175 | |
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176 | .. rubric:: OPTION TYPE: |
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177 | |
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178 | This configuration option is an integer define. |
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179 | |
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180 | .. rubric:: DEFAULT VALUE: |
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181 | |
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182 | The default value is 0. |
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183 | |
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184 | .. rubric:: DESCRIPTION: |
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185 | |
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186 | The value of this configuration option defines the number of bytes the |
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187 | applications wishes to add to the task stack requirements calculated by |
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188 | ``<rtems/confdefs.h>``. |
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189 | |
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190 | .. rubric:: NOTES: |
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191 | |
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192 | This parameter is very important. If the application creates tasks with |
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193 | stacks larger then the minimum, then that memory is **not** accounted for by |
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194 | ``<rtems/confdefs.h>``. |
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195 | |
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196 | .. rubric:: CONSTRAINTS: |
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197 | |
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198 | The following constraints apply to this configuration option: |
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199 | |
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200 | * The value of the configuration option shall be greater than or equal to zero. |
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201 | |
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202 | * The value of the configuration option shall be small enough so that the task |
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203 | stack space calculation carried out by ``<rtems/confdefs.h>`` does not |
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204 | overflow an integer of type `uintptr_t |
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205 | <https://en.cppreference.com/w/c/types/integer>`_. |
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206 | |
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207 | .. Generated from spec:/acfg/if/initial-extensions |
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208 | |
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209 | .. raw:: latex |
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210 | |
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211 | \clearpage |
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212 | |
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213 | .. index:: CONFIGURE_INITIAL_EXTENSIONS |
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214 | |
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215 | .. _CONFIGURE_INITIAL_EXTENSIONS: |
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216 | |
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217 | CONFIGURE_INITIAL_EXTENSIONS |
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218 | ---------------------------- |
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219 | |
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220 | .. rubric:: CONSTANT: |
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221 | |
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222 | ``CONFIGURE_INITIAL_EXTENSIONS`` |
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223 | |
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224 | .. rubric:: OPTION TYPE: |
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225 | |
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226 | This configuration option is an initializer define. |
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227 | |
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228 | .. rubric:: DEFAULT VALUE: |
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229 | |
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230 | The default value is the empty list. |
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231 | |
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232 | .. rubric:: DESCRIPTION: |
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233 | |
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234 | The value of this configuration option is used to initialize the table of |
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235 | initial user extensions. |
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236 | |
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237 | .. rubric:: NOTES: |
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238 | |
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239 | The value of this configuration option is placed before the entries of |
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240 | :ref:`BSP_INITIAL_EXTENSION` and after the entries of all other initial |
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241 | user extensions. |
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242 | |
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243 | .. rubric:: CONSTRAINTS: |
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244 | |
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245 | The value of the configuration option shall be a list of initializers for |
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246 | structures of type :c:type:`rtems_extensions_table`. |
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247 | |
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248 | .. Generated from spec:/acfg/if/interrupt-stack-size |
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249 | |
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250 | .. raw:: latex |
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251 | |
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252 | \clearpage |
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253 | |
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254 | .. index:: CONFIGURE_INTERRUPT_STACK_SIZE |
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255 | .. index:: interrupt stack size |
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256 | |
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257 | .. _CONFIGURE_INTERRUPT_STACK_SIZE: |
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258 | |
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259 | CONFIGURE_INTERRUPT_STACK_SIZE |
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260 | ------------------------------ |
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261 | |
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262 | .. rubric:: CONSTANT: |
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263 | |
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264 | ``CONFIGURE_INTERRUPT_STACK_SIZE`` |
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265 | |
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266 | .. rubric:: OPTION TYPE: |
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267 | |
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268 | This configuration option is an integer define. |
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269 | |
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270 | .. rubric:: DEFAULT VALUE: |
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271 | |
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272 | The default value is :ref:`BSP_INTERRUPT_STACK_SIZE` in case it is defined, |
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273 | otherwise the default value is :c:macro:`CPU_STACK_MINIMUM_SIZE`. |
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274 | |
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275 | .. rubric:: DESCRIPTION: |
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276 | |
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277 | The value of this configuration option defines the size of an interrupt stack |
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278 | in bytes. |
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279 | |
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280 | .. rubric:: NOTES: |
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281 | |
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282 | There is one interrupt stack available for each configured processor |
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283 | (:ref:`CONFIGURE_MAXIMUM_PROCESSORS`). The interrupt stack areas are |
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284 | statically allocated in a special linker section (``.rtemsstack.interrupt``). |
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285 | The placement of this linker section is BSP-specific. |
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286 | |
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287 | Some BSPs use the interrupt stack as the initialization stack which is used |
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288 | to perform the sequential system initialization before the multithreading |
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289 | is started. |
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290 | |
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291 | The interrupt stacks are covered by the stack checker, see |
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292 | :ref:`CONFIGURE_STACK_CHECKER_ENABLED`. However, using a too small interrupt stack |
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293 | size may still result in undefined behaviour. |
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294 | |
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295 | In releases before RTEMS 5.1 the default value was |
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296 | :ref:`CONFIGURE_MINIMUM_TASK_STACK_SIZE` instead of |
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297 | :c:macro:`CPU_STACK_MINIMUM_SIZE`. |
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298 | |
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299 | .. rubric:: CONSTRAINTS: |
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300 | |
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301 | The following constraints apply to this configuration option: |
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302 | |
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303 | * The value of the configuration option shall be greater than or equal to a |
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304 | BSP-specific and application-specific minimum value. |
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305 | |
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306 | * The value of the configuration option shall be small enough so that the |
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307 | interrupt stack area calculation carried out by ``<rtems/confdefs.h>`` does |
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308 | not overflow an integer of type `size_t |
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309 | <https://en.cppreference.com/w/c/types/size_t>`_. |
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310 | |
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311 | * The value of the configuration option shall be aligned according to |
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312 | :c:macro:`CPU_INTERRUPT_STACK_ALIGNMENT`. |
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313 | |
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314 | .. Generated from spec:/acfg/if/malloc-dirty |
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315 | |
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316 | .. raw:: latex |
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317 | |
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318 | \clearpage |
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319 | |
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320 | .. index:: CONFIGURE_MALLOC_DIRTY |
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321 | |
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322 | .. _CONFIGURE_MALLOC_DIRTY: |
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323 | |
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324 | CONFIGURE_MALLOC_DIRTY |
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325 | ---------------------- |
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326 | |
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327 | .. rubric:: CONSTANT: |
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328 | |
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329 | ``CONFIGURE_MALLOC_DIRTY`` |
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330 | |
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331 | .. rubric:: OPTION TYPE: |
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332 | |
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333 | This configuration option is a boolean feature define. |
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334 | |
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335 | .. rubric:: DEFAULT CONFIGURATION: |
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336 | |
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337 | If this configuration option is undefined, then the described feature is not |
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338 | enabled. |
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339 | |
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340 | .. rubric:: DESCRIPTION: |
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341 | |
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342 | In case this configuration option is defined, then each memory area returned |
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343 | by C Program Heap allocator functions such as :c:func:`malloc` is dirtied |
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344 | with a ``0xCF`` byte pattern before it is handed over to the application. |
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345 | |
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346 | .. rubric:: NOTES: |
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347 | |
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348 | The dirtying performed by this option is carried out for each successful |
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349 | memory allocation from the C Program Heap in contrast to |
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350 | :ref:`CONFIGURE_DIRTY_MEMORY` which dirties the memory only once during the |
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351 | system initialization. |
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352 | |
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353 | .. Generated from spec:/acfg/if/max-file-descriptors |
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354 | |
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355 | .. raw:: latex |
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356 | |
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357 | \clearpage |
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358 | |
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359 | .. index:: CONFIGURE_MAXIMUM_FILE_DESCRIPTORS |
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360 | .. index:: maximum file descriptors |
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361 | |
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362 | .. _CONFIGURE_MAXIMUM_FILE_DESCRIPTORS: |
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363 | |
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364 | CONFIGURE_MAXIMUM_FILE_DESCRIPTORS |
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365 | ---------------------------------- |
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366 | |
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367 | .. rubric:: CONSTANT: |
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368 | |
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369 | ``CONFIGURE_MAXIMUM_FILE_DESCRIPTORS`` |
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370 | |
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371 | .. rubric:: OPTION TYPE: |
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372 | |
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373 | This configuration option is an integer define. |
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374 | |
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375 | .. rubric:: DEFAULT VALUE: |
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376 | |
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377 | The default value is 3. |
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378 | |
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379 | .. rubric:: DESCRIPTION: |
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380 | |
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381 | The value of this configuration option defines the maximum number of file |
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382 | like objects that can be concurrently open. |
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383 | |
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384 | .. rubric:: NOTES: |
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385 | |
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386 | The default value of three file descriptors allows RTEMS to support standard |
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387 | input, output, and error I/O streams on :file:`/dev/console`. |
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388 | |
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389 | .. rubric:: CONSTRAINTS: |
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390 | |
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391 | The following constraints apply to this configuration option: |
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392 | |
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393 | * The value of the configuration option shall be greater than or equal to zero. |
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394 | |
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395 | * The value of the configuration option shall be less than or equal to |
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396 | `SIZE_MAX <https://en.cppreference.com/w/c/types/limits>`_. |
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397 | |
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398 | * The value of the configuration option shall be less than or equal to a |
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399 | BSP-specific and application-specific value which depends on the size of the |
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400 | memory available to the application. |
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401 | |
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402 | .. Generated from spec:/acfg/if/max-processors |
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403 | |
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404 | .. raw:: latex |
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405 | |
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406 | \clearpage |
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407 | |
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408 | .. index:: CONFIGURE_MAXIMUM_PROCESSORS |
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409 | |
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410 | .. _CONFIGURE_MAXIMUM_PROCESSORS: |
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411 | |
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412 | CONFIGURE_MAXIMUM_PROCESSORS |
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413 | ---------------------------- |
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414 | |
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415 | .. rubric:: CONSTANT: |
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416 | |
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417 | ``CONFIGURE_MAXIMUM_PROCESSORS`` |
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418 | |
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419 | .. rubric:: OPTION TYPE: |
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420 | |
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421 | This configuration option is an integer define. |
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422 | |
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423 | .. rubric:: DEFAULT VALUE: |
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424 | |
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425 | The default value is 1. |
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426 | |
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427 | .. rubric:: DESCRIPTION: |
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428 | |
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429 | The value of this configuration option defines the maximum number of |
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430 | processors an application intends to use. The number of actually available |
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431 | processors depends on the hardware and may be less. It is recommended to use |
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432 | the smallest value suitable for the application in order to save memory. |
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433 | Each processor needs an IDLE task stack and interrupt stack for example. |
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434 | |
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435 | .. rubric:: NOTES: |
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436 | |
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437 | If there are more processors available than configured, the rest will be |
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438 | ignored. |
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439 | |
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440 | This configuration option is only evaluated in SMP configurations of RTEMS |
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441 | (e.g. RTEMS was built with the SMP build configuration option enabled). |
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442 | In all other configurations it has no effect. |
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443 | |
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444 | .. rubric:: CONSTRAINTS: |
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445 | |
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446 | The following constraints apply to this configuration option: |
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447 | |
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448 | * The value of the configuration option shall be greater than or equal to one. |
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449 | |
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450 | * The value of the configuration option shall be less than or equal to |
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451 | :c:macro:`CPU_MAXIMUM_PROCESSORS`. |
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452 | |
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453 | .. Generated from spec:/acfg/if/max-thread-name-size |
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454 | |
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455 | .. raw:: latex |
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456 | |
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457 | \clearpage |
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458 | |
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459 | .. index:: CONFIGURE_MAXIMUM_THREAD_NAME_SIZE |
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460 | .. index:: maximum thread name size |
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461 | |
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462 | .. _CONFIGURE_MAXIMUM_THREAD_NAME_SIZE: |
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463 | |
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464 | CONFIGURE_MAXIMUM_THREAD_NAME_SIZE |
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465 | ---------------------------------- |
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466 | |
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467 | .. rubric:: CONSTANT: |
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468 | |
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469 | ``CONFIGURE_MAXIMUM_THREAD_NAME_SIZE`` |
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470 | |
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471 | .. rubric:: OPTION TYPE: |
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472 | |
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473 | This configuration option is an integer define. |
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474 | |
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475 | .. rubric:: DEFAULT VALUE: |
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476 | |
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477 | The default value is 16. |
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478 | |
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479 | .. rubric:: DESCRIPTION: |
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480 | |
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481 | The value of this configuration option defines the maximum thread name size |
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482 | including the terminating ``NUL`` character. |
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483 | |
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484 | .. rubric:: NOTES: |
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485 | |
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486 | The default value was chosen for Linux compatibility, see |
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487 | `pthread_setname_np() <http://man7.org/linux/man-pages/man3/pthread_setname_np.3.html>`_. |
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488 | |
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489 | The size of the thread control block is increased by the maximum thread name |
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490 | size. |
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491 | |
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492 | This configuration option is available since RTEMS 5.1. |
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493 | |
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494 | .. rubric:: CONSTRAINTS: |
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495 | |
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496 | The following constraints apply to this configuration option: |
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497 | |
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498 | * The value of the configuration option shall be greater than or equal to zero. |
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499 | |
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500 | * The value of the configuration option shall be less than or equal to |
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501 | `SIZE_MAX <https://en.cppreference.com/w/c/types/limits>`_. |
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502 | |
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503 | * The value of the configuration option shall be less than or equal to a |
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504 | BSP-specific and application-specific value which depends on the size of the |
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505 | memory available to the application. |
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506 | |
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507 | .. Generated from spec:/acfg/if/memory-overhead |
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508 | |
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509 | .. raw:: latex |
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510 | |
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511 | \clearpage |
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512 | |
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513 | .. index:: CONFIGURE_MEMORY_OVERHEAD |
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514 | |
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515 | .. _CONFIGURE_MEMORY_OVERHEAD: |
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516 | |
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517 | CONFIGURE_MEMORY_OVERHEAD |
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518 | ------------------------- |
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519 | |
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520 | .. rubric:: CONSTANT: |
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521 | |
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522 | ``CONFIGURE_MEMORY_OVERHEAD`` |
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523 | |
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524 | .. rubric:: OPTION TYPE: |
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525 | |
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526 | This configuration option is an integer define. |
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527 | |
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528 | .. rubric:: DEFAULT VALUE: |
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529 | |
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530 | The default value is 0. |
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531 | |
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532 | .. rubric:: DESCRIPTION: |
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533 | |
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534 | The value of this configuration option defines the number of kilobytes the |
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535 | application wishes to add to the RTEMS Workspace size calculated by |
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536 | ``<rtems/confdefs.h>``. |
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537 | |
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538 | .. rubric:: NOTES: |
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539 | |
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540 | This configuration option should only be used when it is suspected that a bug |
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541 | in ``<rtems/confdefs.h>`` has resulted in an underestimation. Typically the |
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542 | memory allocation will be too low when an application does not account for |
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543 | all message queue buffers or task stacks, see |
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544 | :ref:`CONFIGURE_MESSAGE_BUFFER_MEMORY`. |
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545 | |
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546 | .. rubric:: CONSTRAINTS: |
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547 | |
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548 | The following constraints apply to this configuration option: |
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549 | |
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550 | * The value of the configuration option shall be greater than or equal to zero. |
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551 | |
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552 | * The value of the configuration option shall be less than or equal to a |
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553 | BSP-specific and application-specific value which depends on the size of the |
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554 | memory available to the application. |
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555 | |
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556 | * The value of the configuration option shall be small enough so that the RTEMS |
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557 | Workspace size calculation carried out by ``<rtems/confdefs.h>`` does not |
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558 | overflow an integer of type `uintptr_t |
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559 | <https://en.cppreference.com/w/c/types/integer>`_. |
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560 | |
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561 | .. Generated from spec:/acfg/if/message-buffer-memory |
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562 | |
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563 | .. raw:: latex |
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564 | |
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565 | \clearpage |
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566 | |
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567 | .. index:: CONFIGURE_MESSAGE_BUFFER_MEMORY |
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568 | .. index:: configure message queue buffer memory |
---|
569 | .. index:: CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE |
---|
570 | .. index:: memory for a single message queue's buffers |
---|
571 | |
---|
572 | .. _CONFIGURE_MESSAGE_BUFFER_MEMORY: |
---|
573 | |
---|
574 | CONFIGURE_MESSAGE_BUFFER_MEMORY |
---|
575 | ------------------------------- |
---|
576 | |
---|
577 | .. rubric:: CONSTANT: |
---|
578 | |
---|
579 | ``CONFIGURE_MESSAGE_BUFFER_MEMORY`` |
---|
580 | |
---|
581 | .. rubric:: OPTION TYPE: |
---|
582 | |
---|
583 | This configuration option is an integer define. |
---|
584 | |
---|
585 | .. rubric:: DEFAULT VALUE: |
---|
586 | |
---|
587 | The default value is 0. |
---|
588 | |
---|
589 | .. rubric:: DESCRIPTION: |
---|
590 | |
---|
591 | The value of this configuration option defines the number of bytes reserved |
---|
592 | for message queue buffers in the RTEMS Workspace. |
---|
593 | |
---|
594 | .. rubric:: NOTES: |
---|
595 | |
---|
596 | The configuration options :ref:`CONFIGURE_MAXIMUM_MESSAGE_QUEUES` and |
---|
597 | :ref:`CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES` define only how many message |
---|
598 | queues can be created by the application. The memory for the message |
---|
599 | buffers is configured by this option. For each message queue you have to |
---|
600 | reserve some memory for the message buffers. The size depends on the |
---|
601 | maximum number of pending messages and the maximum size of the messages of |
---|
602 | a message queue. Use the ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()`` macro |
---|
603 | to specify the message buffer memory for each message queue and sum them up |
---|
604 | to define the value for ``CONFIGURE_MAXIMUM_MESSAGE_QUEUES``. |
---|
605 | |
---|
606 | The interface for the ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()`` help |
---|
607 | macro is as follows: |
---|
608 | |
---|
609 | .. code-block:: c |
---|
610 | |
---|
611 | CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( max_messages, max_msg_size ) |
---|
612 | |
---|
613 | Where ``max_messages`` is the maximum number of pending messages and |
---|
614 | ``max_msg_size`` is the maximum size in bytes of the messages of the |
---|
615 | corresponding message queue. Both parameters shall be compile time |
---|
616 | constants. Not using this help macro (e.g. just using |
---|
617 | ``max_messages * max_msg_size``) may result in an underestimate of the |
---|
618 | RTEMS Workspace size. |
---|
619 | |
---|
620 | The following example illustrates how the |
---|
621 | ``CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE()`` help macro can be used to assist in |
---|
622 | calculating the message buffer memory required. In this example, there are |
---|
623 | two message queues used in this application. The first message queue has a |
---|
624 | maximum of 24 pending messages with the message structure defined by the |
---|
625 | type ``one_message_type``. The other message queue has a maximum of 500 |
---|
626 | pending messages with the message structure defined by the type |
---|
627 | ``other_message_type``. |
---|
628 | |
---|
629 | .. code-block:: c |
---|
630 | |
---|
631 | #define CONFIGURE_MESSAGE_BUFFER_MEMORY ( \ |
---|
632 | CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \ |
---|
633 | 24, \ |
---|
634 | sizeof( one_message_type ) \ |
---|
635 | ) \ |
---|
636 | + CONFIGURE_MESSAGE_BUFFERS_FOR_QUEUE( \ |
---|
637 | 500, \ |
---|
638 | sizeof( other_message_type ) \ |
---|
639 | ) \ |
---|
640 | ) |
---|
641 | |
---|
642 | .. rubric:: CONSTRAINTS: |
---|
643 | |
---|
644 | The following constraints apply to this configuration option: |
---|
645 | |
---|
646 | * The value of the configuration option shall be greater than or equal to zero. |
---|
647 | |
---|
648 | * The value of the configuration option shall be less than or equal to a |
---|
649 | BSP-specific and application-specific value which depends on the size of the |
---|
650 | memory available to the application. |
---|
651 | |
---|
652 | * The value of the configuration option shall be small enough so that the RTEMS |
---|
653 | Workspace size calculation carried out by ``<rtems/confdefs.h>`` does not |
---|
654 | overflow an integer of type `uintptr_t |
---|
655 | <https://en.cppreference.com/w/c/types/integer>`_. |
---|
656 | |
---|
657 | .. Generated from spec:/acfg/if/microseconds-per-tick |
---|
658 | |
---|
659 | .. raw:: latex |
---|
660 | |
---|
661 | \clearpage |
---|
662 | |
---|
663 | .. index:: CONFIGURE_MICROSECONDS_PER_TICK |
---|
664 | .. index:: clock tick quantum |
---|
665 | .. index:: tick quantum |
---|
666 | |
---|
667 | .. _CONFIGURE_MICROSECONDS_PER_TICK: |
---|
668 | |
---|
669 | CONFIGURE_MICROSECONDS_PER_TICK |
---|
670 | ------------------------------- |
---|
671 | |
---|
672 | .. rubric:: CONSTANT: |
---|
673 | |
---|
674 | ``CONFIGURE_MICROSECONDS_PER_TICK`` |
---|
675 | |
---|
676 | .. rubric:: OPTION TYPE: |
---|
677 | |
---|
678 | This configuration option is an integer define. |
---|
679 | |
---|
680 | .. rubric:: DEFAULT VALUE: |
---|
681 | |
---|
682 | The default value is 10000. |
---|
683 | |
---|
684 | .. rubric:: DESCRIPTION: |
---|
685 | |
---|
686 | The value of this configuration option defines the length of time in |
---|
687 | microseconds between clock ticks (clock tick quantum). |
---|
688 | |
---|
689 | When the clock tick quantum value is too low, the system will spend so much |
---|
690 | time processing clock ticks that it does not have processing time available |
---|
691 | to perform application work. In this case, the system will become |
---|
692 | unresponsive. |
---|
693 | |
---|
694 | The lowest practical time quantum varies widely based upon the speed of the |
---|
695 | target hardware and the architectural overhead associated with |
---|
696 | interrupts. In general terms, you do not want to configure it lower than is |
---|
697 | needed for the application. |
---|
698 | |
---|
699 | The clock tick quantum should be selected such that it all blocking and |
---|
700 | delay times in the application are evenly divisible by it. Otherwise, |
---|
701 | rounding errors will be introduced which may negatively impact the |
---|
702 | application. |
---|
703 | |
---|
704 | .. rubric:: NOTES: |
---|
705 | |
---|
706 | This configuration option has no impact if the Clock Driver is not |
---|
707 | configured, see :ref:`CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`. |
---|
708 | |
---|
709 | There may be Clock Driver specific limits on the resolution or maximum value |
---|
710 | of a clock tick quantum. |
---|
711 | |
---|
712 | .. rubric:: CONSTRAINTS: |
---|
713 | |
---|
714 | The following constraints apply to this configuration option: |
---|
715 | |
---|
716 | * The value of the configuration option shall be greater than or equal to a |
---|
717 | value defined by the :term:`Clock Driver`. |
---|
718 | |
---|
719 | * The value of the configuration option shall be less than or equal to a value |
---|
720 | defined by the :term:`Clock Driver`. |
---|
721 | |
---|
722 | * The resulting clock ticks per second should be an integer. |
---|
723 | |
---|
724 | .. Generated from spec:/acfg/if/min-task-stack-size |
---|
725 | |
---|
726 | .. raw:: latex |
---|
727 | |
---|
728 | \clearpage |
---|
729 | |
---|
730 | .. index:: CONFIGURE_MINIMUM_TASK_STACK_SIZE |
---|
731 | .. index:: minimum task stack size |
---|
732 | |
---|
733 | .. _CONFIGURE_MINIMUM_TASK_STACK_SIZE: |
---|
734 | |
---|
735 | CONFIGURE_MINIMUM_TASK_STACK_SIZE |
---|
736 | --------------------------------- |
---|
737 | |
---|
738 | .. rubric:: CONSTANT: |
---|
739 | |
---|
740 | ``CONFIGURE_MINIMUM_TASK_STACK_SIZE`` |
---|
741 | |
---|
742 | .. rubric:: OPTION TYPE: |
---|
743 | |
---|
744 | This configuration option is an integer define. |
---|
745 | |
---|
746 | .. rubric:: DEFAULT VALUE: |
---|
747 | |
---|
748 | The default value is :c:macro:`CPU_STACK_MINIMUM_SIZE`. |
---|
749 | |
---|
750 | .. rubric:: DESCRIPTION: |
---|
751 | |
---|
752 | The value of this configuration option defines the minimum stack size in |
---|
753 | bytes for every user task or thread in the system. |
---|
754 | |
---|
755 | .. rubric:: NOTES: |
---|
756 | |
---|
757 | Adjusting this parameter should be done with caution. Examining the actual |
---|
758 | stack usage using the stack checker usage reporting facility is recommended |
---|
759 | (see also :ref:`CONFIGURE_STACK_CHECKER_ENABLED`). |
---|
760 | |
---|
761 | This parameter can be used to lower the minimum from that recommended. This |
---|
762 | can be used in low memory systems to reduce memory consumption for |
---|
763 | stacks. However, this shall be done with caution as it could increase the |
---|
764 | possibility of a blown task stack. |
---|
765 | |
---|
766 | This parameter can be used to increase the minimum from that |
---|
767 | recommended. This can be used in higher memory systems to reduce the risk |
---|
768 | of stack overflow without performing analysis on actual consumption. |
---|
769 | |
---|
770 | By default, this configuration parameter defines also the minimum stack |
---|
771 | size of POSIX threads. This can be changed with the |
---|
772 | :ref:`CONFIGURE_MINIMUM_POSIX_THREAD_STACK_SIZE` |
---|
773 | configuration option. |
---|
774 | |
---|
775 | In releases before RTEMS 5.1 the ``CONFIGURE_MINIMUM_TASK_STACK_SIZE`` was |
---|
776 | used to define the default value of :ref:`CONFIGURE_INTERRUPT_STACK_SIZE`. |
---|
777 | |
---|
778 | .. rubric:: CONSTRAINTS: |
---|
779 | |
---|
780 | The following constraints apply to this configuration option: |
---|
781 | |
---|
782 | * The value of the configuration option shall be small enough so that the task |
---|
783 | stack space calculation carried out by ``<rtems/confdefs.h>`` does not |
---|
784 | overflow an integer of type `uintptr_t |
---|
785 | <https://en.cppreference.com/w/c/types/integer>`_. |
---|
786 | |
---|
787 | * The value of the configuration option shall be greater than or equal to a |
---|
788 | BSP-specific and application-specific minimum value. |
---|
789 | |
---|
790 | .. Generated from spec:/acfg/if/stack-checker-enabled |
---|
791 | |
---|
792 | .. raw:: latex |
---|
793 | |
---|
794 | \clearpage |
---|
795 | |
---|
796 | .. index:: CONFIGURE_STACK_CHECKER_ENABLED |
---|
797 | |
---|
798 | .. _CONFIGURE_STACK_CHECKER_ENABLED: |
---|
799 | |
---|
800 | CONFIGURE_STACK_CHECKER_ENABLED |
---|
801 | ------------------------------- |
---|
802 | |
---|
803 | .. rubric:: CONSTANT: |
---|
804 | |
---|
805 | ``CONFIGURE_STACK_CHECKER_ENABLED`` |
---|
806 | |
---|
807 | .. rubric:: OPTION TYPE: |
---|
808 | |
---|
809 | This configuration option is a boolean feature define. |
---|
810 | |
---|
811 | .. rubric:: DEFAULT CONFIGURATION: |
---|
812 | |
---|
813 | If this configuration option is undefined, then the described feature is not |
---|
814 | enabled. |
---|
815 | |
---|
816 | .. rubric:: DESCRIPTION: |
---|
817 | |
---|
818 | In case this configuration option is defined, then the stack checker is |
---|
819 | enabled. |
---|
820 | |
---|
821 | .. rubric:: NOTES: |
---|
822 | |
---|
823 | The stack checker performs run-time stack bounds checking. This increases |
---|
824 | the time required to create tasks as well as adding overhead to each context |
---|
825 | switch. |
---|
826 | |
---|
827 | In 4.9 and older, this configuration option was named ``STACK_CHECKER_ON``. |
---|
828 | |
---|
829 | .. Generated from spec:/acfg/if/ticks-per-time-slice |
---|
830 | |
---|
831 | .. raw:: latex |
---|
832 | |
---|
833 | \clearpage |
---|
834 | |
---|
835 | .. index:: CONFIGURE_TICKS_PER_TIMESLICE |
---|
836 | .. index:: ticks per timeslice |
---|
837 | |
---|
838 | .. _CONFIGURE_TICKS_PER_TIMESLICE: |
---|
839 | |
---|
840 | CONFIGURE_TICKS_PER_TIMESLICE |
---|
841 | ----------------------------- |
---|
842 | |
---|
843 | .. rubric:: CONSTANT: |
---|
844 | |
---|
845 | ``CONFIGURE_TICKS_PER_TIMESLICE`` |
---|
846 | |
---|
847 | .. rubric:: OPTION TYPE: |
---|
848 | |
---|
849 | This configuration option is an integer define. |
---|
850 | |
---|
851 | .. rubric:: DEFAULT VALUE: |
---|
852 | |
---|
853 | The default value is 50. |
---|
854 | |
---|
855 | .. rubric:: DESCRIPTION: |
---|
856 | |
---|
857 | The value of this configuration option defines the length of the timeslice |
---|
858 | quantum in ticks for each task. |
---|
859 | |
---|
860 | .. rubric:: NOTES: |
---|
861 | |
---|
862 | This configuration option has no impact if the Clock Driver is not |
---|
863 | configured, see :ref:`CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER`. |
---|
864 | |
---|
865 | .. rubric:: CONSTRAINTS: |
---|
866 | |
---|
867 | The following constraints apply to this configuration option: |
---|
868 | |
---|
869 | * The value of the configuration option shall be greater than or equal to zero. |
---|
870 | |
---|
871 | * The value of the configuration option shall be less than or equal to |
---|
872 | `UINT32_MAX <https://en.cppreference.com/w/c/types/integer>`_. |
---|
873 | |
---|
874 | .. Generated from spec:/acfg/if/unified-work-areas |
---|
875 | |
---|
876 | .. raw:: latex |
---|
877 | |
---|
878 | \clearpage |
---|
879 | |
---|
880 | .. index:: CONFIGURE_UNIFIED_WORK_AREAS |
---|
881 | .. index:: unified work areas |
---|
882 | .. index:: separate work areas |
---|
883 | .. index:: RTEMS Workspace |
---|
884 | .. index:: C Program Heap |
---|
885 | |
---|
886 | .. _CONFIGURE_UNIFIED_WORK_AREAS: |
---|
887 | |
---|
888 | CONFIGURE_UNIFIED_WORK_AREAS |
---|
889 | ---------------------------- |
---|
890 | |
---|
891 | .. rubric:: CONSTANT: |
---|
892 | |
---|
893 | ``CONFIGURE_UNIFIED_WORK_AREAS`` |
---|
894 | |
---|
895 | .. rubric:: OPTION TYPE: |
---|
896 | |
---|
897 | This configuration option is a boolean feature define. |
---|
898 | |
---|
899 | .. rubric:: DEFAULT CONFIGURATION: |
---|
900 | |
---|
901 | If this configuration option is undefined, then there will be separate memory |
---|
902 | pools for the RTEMS Workspace and C Program Heap. |
---|
903 | |
---|
904 | .. rubric:: DESCRIPTION: |
---|
905 | |
---|
906 | In case this configuration option is defined, then the RTEMS Workspace and |
---|
907 | the C Program Heap will be one pool of memory. |
---|
908 | |
---|
909 | .. rubric:: NOTES: |
---|
910 | |
---|
911 | Having separate pools does have some advantages in the event a task blows a |
---|
912 | stack or writes outside its memory area. However, in low memory systems the |
---|
913 | overhead of the two pools plus the potential for unused memory in either |
---|
914 | pool is very undesirable. |
---|
915 | |
---|
916 | In high memory environments, this is desirable when you want to use the |
---|
917 | :ref:`ConfigUnlimitedObjects` option. You will be able to create objects |
---|
918 | until you run out of all available memory rather then just until you run out |
---|
919 | of RTEMS Workspace. |
---|
920 | |
---|
921 | .. Generated from spec:/acfg/if/unlimited-allocation-size |
---|
922 | |
---|
923 | .. raw:: latex |
---|
924 | |
---|
925 | \clearpage |
---|
926 | |
---|
927 | .. index:: CONFIGURE_UNLIMITED_ALLOCATION_SIZE |
---|
928 | |
---|
929 | .. _CONFIGURE_UNLIMITED_ALLOCATION_SIZE: |
---|
930 | |
---|
931 | CONFIGURE_UNLIMITED_ALLOCATION_SIZE |
---|
932 | ----------------------------------- |
---|
933 | |
---|
934 | .. rubric:: CONSTANT: |
---|
935 | |
---|
936 | ``CONFIGURE_UNLIMITED_ALLOCATION_SIZE`` |
---|
937 | |
---|
938 | .. rubric:: OPTION TYPE: |
---|
939 | |
---|
940 | This configuration option is an integer define. |
---|
941 | |
---|
942 | .. rubric:: DEFAULT VALUE: |
---|
943 | |
---|
944 | The default value is 8. |
---|
945 | |
---|
946 | .. rubric:: DESCRIPTION: |
---|
947 | |
---|
948 | If :ref:`CONFIGURE_UNLIMITED_OBJECTS` is defined, then the value of this |
---|
949 | configuration option defines the default objects maximum of all object |
---|
950 | classes supporting :ref:`ConfigUnlimitedObjects` to |
---|
951 | ``rtems_resource_unlimited( CONFIGURE_UNLIMITED_ALLOCATION_SIZE )``. |
---|
952 | |
---|
953 | .. rubric:: NOTES: |
---|
954 | |
---|
955 | By allowing users to declare all resources as being unlimited the user can |
---|
956 | avoid identifying and limiting the resources used. |
---|
957 | |
---|
958 | The object maximum of each class can be configured also individually using |
---|
959 | the :c:func:`rtems_resource_unlimited` macro. |
---|
960 | |
---|
961 | .. rubric:: CONSTRAINTS: |
---|
962 | |
---|
963 | The value of the configuration option shall meet the constraints of all object |
---|
964 | classes to which it is applied. |
---|
965 | |
---|
966 | .. Generated from spec:/acfg/if/unlimited-objects |
---|
967 | |
---|
968 | .. raw:: latex |
---|
969 | |
---|
970 | \clearpage |
---|
971 | |
---|
972 | .. index:: CONFIGURE_UNLIMITED_OBJECTS |
---|
973 | |
---|
974 | .. _CONFIGURE_UNLIMITED_OBJECTS: |
---|
975 | |
---|
976 | CONFIGURE_UNLIMITED_OBJECTS |
---|
977 | --------------------------- |
---|
978 | |
---|
979 | .. rubric:: CONSTANT: |
---|
980 | |
---|
981 | ``CONFIGURE_UNLIMITED_OBJECTS`` |
---|
982 | |
---|
983 | .. rubric:: OPTION TYPE: |
---|
984 | |
---|
985 | This configuration option is a boolean feature define. |
---|
986 | |
---|
987 | .. rubric:: DEFAULT CONFIGURATION: |
---|
988 | |
---|
989 | If this configuration option is undefined, then the described feature is not |
---|
990 | enabled. |
---|
991 | |
---|
992 | .. rubric:: DESCRIPTION: |
---|
993 | |
---|
994 | In case this configuration option is defined, then unlimited objects are used |
---|
995 | by default. |
---|
996 | |
---|
997 | .. rubric:: NOTES: |
---|
998 | |
---|
999 | When using unlimited objects, it is common practice to also specify |
---|
1000 | :ref:`CONFIGURE_UNIFIED_WORK_AREAS` so the system operates with a single pool |
---|
1001 | of memory for both RTEMS Workspace and C Program Heap. |
---|
1002 | |
---|
1003 | This option does not override an explicit configuration for a particular |
---|
1004 | object class by the user. |
---|
1005 | |
---|
1006 | See also :ref:`CONFIGURE_UNLIMITED_ALLOCATION_SIZE`. |
---|
1007 | |
---|
1008 | .. Generated from spec:/acfg/if/verbose-system-init |
---|
1009 | |
---|
1010 | .. raw:: latex |
---|
1011 | |
---|
1012 | \clearpage |
---|
1013 | |
---|
1014 | .. index:: CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION |
---|
1015 | |
---|
1016 | .. _CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION: |
---|
1017 | |
---|
1018 | CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION |
---|
1019 | --------------------------------------- |
---|
1020 | |
---|
1021 | .. rubric:: CONSTANT: |
---|
1022 | |
---|
1023 | ``CONFIGURE_VERBOSE_SYSTEM_INITIALIZATION`` |
---|
1024 | |
---|
1025 | .. rubric:: OPTION TYPE: |
---|
1026 | |
---|
1027 | This configuration option is a boolean feature define. |
---|
1028 | |
---|
1029 | .. rubric:: DEFAULT CONFIGURATION: |
---|
1030 | |
---|
1031 | If this configuration option is undefined, then the described feature is not |
---|
1032 | enabled. |
---|
1033 | |
---|
1034 | .. rubric:: DESCRIPTION: |
---|
1035 | |
---|
1036 | In case this configuration option is defined, then the system initialization |
---|
1037 | is verbose. |
---|
1038 | |
---|
1039 | .. rubric:: NOTES: |
---|
1040 | |
---|
1041 | You may use this feature to debug system initialization issues. The |
---|
1042 | :c:func:`printk` function is used to print the information. |
---|
1043 | |
---|
1044 | .. Generated from spec:/acfg/if/zero-workspace-automatically |
---|
1045 | |
---|
1046 | .. raw:: latex |
---|
1047 | |
---|
1048 | \clearpage |
---|
1049 | |
---|
1050 | .. index:: CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY |
---|
1051 | .. index:: clear C Program Heap |
---|
1052 | .. index:: clear RTEMS Workspace |
---|
1053 | .. index:: zero C Program Heap |
---|
1054 | .. index:: zero RTEMS Workspace |
---|
1055 | |
---|
1056 | .. _CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY: |
---|
1057 | |
---|
1058 | CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY |
---|
1059 | -------------------------------------- |
---|
1060 | |
---|
1061 | .. rubric:: CONSTANT: |
---|
1062 | |
---|
1063 | ``CONFIGURE_ZERO_WORKSPACE_AUTOMATICALLY`` |
---|
1064 | |
---|
1065 | .. rubric:: OPTION TYPE: |
---|
1066 | |
---|
1067 | This configuration option is a boolean feature define. |
---|
1068 | |
---|
1069 | .. rubric:: DEFAULT CONFIGURATION: |
---|
1070 | |
---|
1071 | If this configuration option is undefined, then the described feature is not |
---|
1072 | enabled. |
---|
1073 | |
---|
1074 | .. rubric:: DESCRIPTION: |
---|
1075 | |
---|
1076 | In case this configuration option is defined, then the memory areas used for |
---|
1077 | the RTEMS Workspace and the C Program Heap are zeroed with a ``0x00`` byte |
---|
1078 | pattern during system initialization. |
---|
1079 | |
---|
1080 | .. rubric:: NOTES: |
---|
1081 | |
---|
1082 | Zeroing memory can add significantly to the system initialization time. It is |
---|
1083 | not necessary for RTEMS but is often assumed by support libraries. In case |
---|
1084 | :ref:`CONFIGURE_DIRTY_MEMORY` is also defined, then the memory is first |
---|
1085 | dirtied and then zeroed. |
---|