1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup bsp_clock |
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5 | * |
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6 | * @brief Clock Tick Device Driver Shell |
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7 | */ |
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8 | |
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9 | /* |
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10 | * COPYRIGHT (c) 1989-2012. |
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11 | * On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * The license and distribution terms for this file may be |
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14 | * found in the file LICENSE in this distribution or at |
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15 | * http://www.rtems.com/license/LICENSE. |
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16 | */ |
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17 | |
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18 | #include <stdlib.h> |
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19 | |
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20 | #include <bsp.h> |
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21 | |
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22 | /** |
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23 | * @defgroup bsp_clock Clock Support |
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24 | * |
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25 | * @ingroup bsp_kit |
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26 | * |
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27 | * @brief Clock support |
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28 | * |
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29 | */ |
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30 | #if CLOCK_DRIVER_USE_FAST_IDLE && CLOCK_DRIVER_ISRS_PER_TICK |
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31 | #error "clockdrv_shell.h: Fast Idle PLUS n ISRs per tick is not supported" |
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32 | #endif |
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33 | |
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34 | /** |
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35 | * @brief This method is rarely used so default it. |
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36 | */ |
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37 | #ifndef Clock_driver_support_find_timer |
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38 | #define Clock_driver_support_find_timer() |
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39 | #endif |
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40 | |
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41 | /** |
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42 | * @brief ISRs until next clock tick |
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43 | */ |
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44 | #if CLOCK_DRIVER_ISRS_PER_TICK |
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45 | volatile uint32_t Clock_driver_isrs; |
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46 | #endif |
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47 | |
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48 | /** |
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49 | * @brief Clock ticks since initialization |
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50 | */ |
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51 | volatile uint32_t Clock_driver_ticks; |
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52 | |
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53 | void Clock_exit( void ); |
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54 | |
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55 | /** |
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56 | * @brief Clock_isr |
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57 | * |
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58 | * This is the clock tick interrupt handler. |
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59 | * |
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60 | * @param vector Vector number. |
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61 | * |
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62 | * Output parameters: NONE |
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63 | * |
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64 | * Return values: NONE |
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65 | */ |
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66 | #if defined(BSP_FEATURE_IRQ_EXTENSION) || \ |
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67 | (CPU_SIMPLE_VECTORED_INTERRUPTS != TRUE) |
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68 | void Clock_isr(void *arg) |
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69 | { |
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70 | #else |
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71 | rtems_isr Clock_isr(rtems_vector_number vector); |
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72 | rtems_isr Clock_isr( |
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73 | rtems_vector_number vector |
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74 | ) |
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75 | { |
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76 | #endif |
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77 | /* |
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78 | * Accurate count of ISRs |
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79 | */ |
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80 | Clock_driver_ticks += 1; |
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81 | |
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82 | #if CLOCK_DRIVER_USE_FAST_IDLE |
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83 | do { |
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84 | rtems_clock_tick(); |
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85 | } while ( |
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86 | _Thread_Heir == _Thread_Executing |
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87 | && _Thread_Executing->Start.entry_point |
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88 | == rtems_configuration_get_idle_task() |
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89 | ); |
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90 | |
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91 | Clock_driver_support_at_tick(); |
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92 | return; |
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93 | #else |
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94 | /* |
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95 | * Do the hardware specific per-tick action. |
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96 | * |
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97 | * The counter/timer may or may not be set to automatically reload. |
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98 | */ |
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99 | Clock_driver_support_at_tick(); |
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100 | |
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101 | #if CLOCK_DRIVER_ISRS_PER_TICK |
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102 | /* |
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103 | * The driver is multiple ISRs per clock tick. |
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104 | */ |
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105 | if ( !Clock_driver_isrs ) { |
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106 | rtems_clock_tick(); |
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107 | |
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108 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK; |
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109 | } |
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110 | Clock_driver_isrs--; |
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111 | #else |
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112 | /* |
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113 | * The driver is one ISR per clock tick. |
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114 | */ |
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115 | rtems_clock_tick(); |
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116 | #endif |
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117 | #endif |
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118 | } |
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119 | |
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120 | /** |
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121 | * @brief Clock_exit |
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122 | * |
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123 | * This routine allows the clock driver to exit by masking the interrupt and |
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124 | * disabling the clock's counter. |
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125 | * |
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126 | * Input parameters: NONE |
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127 | * |
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128 | * Output parameters: NONE |
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129 | * |
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130 | * Return values: NONE |
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131 | * |
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132 | */ |
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133 | |
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134 | void Clock_exit( void ) |
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135 | { |
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136 | Clock_driver_support_shutdown_hardware(); |
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137 | |
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138 | /* do not restore old vector */ |
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139 | } |
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140 | |
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141 | /** |
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142 | * @brief Clock_initialize |
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143 | * |
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144 | * This routine initializes the clock driver. |
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145 | * |
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146 | * @param[in] major Clock device major number. |
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147 | * @param[in] minor Clock device minor number. |
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148 | * @param[in] parg Pointer to optional device driver arguments |
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149 | * |
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150 | * @retval rtems_device_driver status code |
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151 | */ |
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152 | |
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153 | rtems_device_driver Clock_initialize( |
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154 | rtems_device_major_number major, |
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155 | rtems_device_minor_number minor, |
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156 | void *pargp |
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157 | ) |
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158 | { |
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159 | rtems_isr_entry Old_ticker; |
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160 | |
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161 | Clock_driver_ticks = 0; |
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162 | |
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163 | /* |
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164 | * Find timer -- some BSPs search buses for hardware timer |
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165 | */ |
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166 | Clock_driver_support_find_timer(); |
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167 | |
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168 | /* |
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169 | * Install vector |
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170 | */ |
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171 | (void) Old_ticker; |
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172 | Clock_driver_support_install_isr( Clock_isr, Old_ticker ); |
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173 | |
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174 | #if defined(Clock_driver_nanoseconds_since_last_tick) |
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175 | rtems_clock_set_nanoseconds_extension( |
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176 | Clock_driver_nanoseconds_since_last_tick |
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177 | ); |
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178 | #endif |
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179 | |
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180 | /* |
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181 | * Now initialize the hardware that is the source of the tick ISR. |
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182 | */ |
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183 | Clock_driver_support_initialize_hardware(); |
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184 | |
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185 | atexit( Clock_exit ); |
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186 | |
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187 | /* |
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188 | * If we are counting ISRs per tick, then initialize the counter. |
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189 | */ |
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190 | #if CLOCK_DRIVER_ISRS_PER_TICK |
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191 | Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK_VALUE; |
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192 | #endif |
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193 | |
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194 | return RTEMS_SUCCESSFUL; |
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195 | } |
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