1 | /* |
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2 | * cpu.c - This file contains implementation of C function to |
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3 | * instantiate IDT entries. More detailled information can be found |
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4 | * on Intel site and more precisely in the following book : |
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5 | * |
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6 | * Pentium Processor family |
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7 | * Developper's Manual |
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8 | * |
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9 | * Volume 3 : Architecture and Programming Manual |
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10 | * |
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11 | * Copyright (C) 1998 Eric Valette (valette@crf.canon.fr) |
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12 | * Canon Centre Recherche France. |
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13 | * |
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14 | * The license and distribution terms for this file may be |
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15 | * found in the file LICENSE in this distribution or at |
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16 | * http://www.rtems.org/license/LICENSE. |
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17 | */ |
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18 | |
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19 | #include <rtems/score/cpu.h> |
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20 | #include <bsp/irq.h> |
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21 | |
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22 | static rtems_raw_irq_connect_data* raw_irq_table; |
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23 | static rtems_raw_irq_connect_data default_raw_irq_entry; |
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24 | static interrupt_gate_descriptor default_idt_entry; |
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25 | static rtems_raw_irq_global_settings* local_settings; |
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26 | |
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27 | void create_interrupt_gate_descriptor (interrupt_gate_descriptor* idtEntry, |
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28 | rtems_raw_irq_hdl hdl) |
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29 | { |
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30 | idtEntry->low_offsets_bits = (((unsigned) hdl) & 0xffff); |
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31 | idtEntry->segment_selector = i386_get_cs(); |
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32 | idtEntry->fixed_value_bits = 0; |
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33 | idtEntry->gate_type = 0xe; |
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34 | idtEntry->privilege = 0; |
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35 | idtEntry->present = 1; |
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36 | idtEntry->high_offsets_bits = ((((unsigned) hdl) >> 16) & 0xffff); |
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37 | } |
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38 | |
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39 | rtems_raw_irq_hdl get_hdl_from_vector(rtems_vector_offset index) |
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40 | { |
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41 | uint32_t hdl; |
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42 | interrupt_gate_descriptor* idt_entry_tbl; |
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43 | unsigned limit; |
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44 | |
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45 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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46 | |
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47 | /* Convert limit into number of entries */ |
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48 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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49 | |
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50 | if(index >= limit) { |
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51 | return 0; |
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52 | } |
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53 | |
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54 | hdl = (idt_entry_tbl[index].low_offsets_bits | |
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55 | (idt_entry_tbl[index].high_offsets_bits << 16)); |
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56 | return (rtems_raw_irq_hdl) hdl; |
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57 | } |
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58 | |
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59 | int i386_set_idt_entry (const rtems_raw_irq_connect_data* irq) |
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60 | { |
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61 | interrupt_gate_descriptor* idt_entry_tbl; |
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62 | unsigned limit; |
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63 | rtems_interrupt_level level; |
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64 | |
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65 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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66 | |
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67 | /* Convert limit into number of entries */ |
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68 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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69 | |
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70 | if (irq->idtIndex >= limit) { |
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71 | return 0; |
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72 | } |
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73 | /* |
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74 | * Check if default handler is actually connected. If not issue an error. |
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75 | * You must first get the current handler via i386_get_current_idt_entry |
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76 | * and then disconnect it using i386_delete_idt_entry. |
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77 | * RATIONALE : to always have the same transition by forcing the user |
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78 | * to get the previous handler before accepting to disconnect. |
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79 | */ |
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80 | if (get_hdl_from_vector(irq->idtIndex) != default_raw_irq_entry.hdl) { |
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81 | return 0; |
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82 | } |
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83 | |
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84 | rtems_interrupt_disable(level); |
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85 | |
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86 | raw_irq_table [irq->idtIndex] = *irq; |
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87 | create_interrupt_gate_descriptor (&idt_entry_tbl[irq->idtIndex], irq->hdl); |
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88 | if (irq->on) |
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89 | irq->on(irq); |
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90 | |
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91 | rtems_interrupt_enable(level); |
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92 | return 1; |
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93 | } |
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94 | |
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95 | void _CPU_ISR_install_vector (uint32_t vector, |
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96 | proc_ptr hdl, |
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97 | proc_ptr * oldHdl) |
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98 | { |
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99 | interrupt_gate_descriptor* idt_entry_tbl; |
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100 | unsigned limit; |
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101 | interrupt_gate_descriptor new; |
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102 | rtems_interrupt_level level; |
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103 | |
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104 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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105 | |
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106 | /* Convert limit into number of entries */ |
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107 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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108 | |
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109 | if (vector >= limit) { |
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110 | return; |
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111 | } |
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112 | rtems_interrupt_disable(level); |
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113 | * ((unsigned int *) oldHdl) = idt_entry_tbl[vector].low_offsets_bits | |
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114 | (idt_entry_tbl[vector].high_offsets_bits << 16); |
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115 | |
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116 | create_interrupt_gate_descriptor(&new, hdl); |
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117 | idt_entry_tbl[vector] = new; |
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118 | |
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119 | rtems_interrupt_enable(level); |
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120 | } |
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121 | |
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122 | int i386_get_current_idt_entry (rtems_raw_irq_connect_data* irq) |
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123 | { |
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124 | interrupt_gate_descriptor* idt_entry_tbl; |
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125 | unsigned limit; |
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126 | |
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127 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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128 | |
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129 | /* Convert limit into number of entries */ |
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130 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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131 | |
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132 | if (irq->idtIndex >= limit) { |
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133 | return 0; |
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134 | } |
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135 | raw_irq_table [irq->idtIndex].hdl = get_hdl_from_vector(irq->idtIndex); |
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136 | |
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137 | *irq = raw_irq_table [irq->idtIndex]; |
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138 | |
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139 | return 1; |
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140 | } |
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141 | |
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142 | int i386_delete_idt_entry (const rtems_raw_irq_connect_data* irq) |
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143 | { |
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144 | interrupt_gate_descriptor* idt_entry_tbl; |
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145 | unsigned limit; |
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146 | rtems_interrupt_level level; |
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147 | |
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148 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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149 | |
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150 | /* Convert limit into number of entries */ |
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151 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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152 | |
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153 | if (irq->idtIndex >= limit) { |
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154 | return 0; |
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155 | } |
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156 | /* |
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157 | * Check if handler passed is actually connected. If not issue an error. |
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158 | * You must first get the current handler via i386_get_current_idt_entry |
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159 | * and then disconnect it using i386_delete_idt_entry. |
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160 | * RATIONALE : to always have the same transition by forcing the user |
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161 | * to get the previous handler before accepting to disconnect. |
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162 | */ |
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163 | if (get_hdl_from_vector(irq->idtIndex) != irq->hdl){ |
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164 | return 0; |
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165 | } |
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166 | rtems_interrupt_disable(level); |
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167 | |
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168 | idt_entry_tbl[irq->idtIndex] = default_idt_entry; |
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169 | |
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170 | if (irq->off) |
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171 | irq->off(irq); |
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172 | |
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173 | raw_irq_table[irq->idtIndex] = default_raw_irq_entry; |
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174 | raw_irq_table[irq->idtIndex].idtIndex = irq->idtIndex; |
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175 | |
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176 | rtems_interrupt_enable(level); |
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177 | |
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178 | return 1; |
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179 | } |
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180 | |
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181 | /* |
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182 | * Caution this function assumes the IDTR has been already set. |
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183 | */ |
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184 | int i386_init_idt (rtems_raw_irq_global_settings* config) |
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185 | { |
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186 | unsigned limit; |
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187 | unsigned i; |
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188 | rtems_interrupt_level level; |
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189 | interrupt_gate_descriptor* idt_entry_tbl; |
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190 | |
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191 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
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192 | |
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193 | /* Convert limit into number of entries */ |
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194 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
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195 | |
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196 | if (config->idtSize != limit) { |
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197 | return 0; |
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198 | } |
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199 | /* |
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200 | * store various accelarators |
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201 | */ |
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202 | raw_irq_table = config->rawIrqHdlTbl; |
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203 | local_settings = config; |
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204 | default_raw_irq_entry = config->defaultRawEntry; |
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205 | |
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206 | rtems_interrupt_disable(level); |
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207 | |
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208 | create_interrupt_gate_descriptor (&default_idt_entry, default_raw_irq_entry.hdl); |
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209 | |
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210 | for (i=0; i < limit; i++) { |
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211 | interrupt_gate_descriptor new; |
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212 | create_interrupt_gate_descriptor (&new, raw_irq_table[i].hdl); |
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213 | idt_entry_tbl[i] = new; |
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214 | if (raw_irq_table[i].hdl != default_raw_irq_entry.hdl) { |
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215 | raw_irq_table[i].on(&raw_irq_table[i]); |
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216 | } |
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217 | else { |
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218 | raw_irq_table[i].off(&raw_irq_table[i]); |
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219 | } |
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220 | } |
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221 | rtems_interrupt_enable(level); |
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222 | |
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223 | return 1; |
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224 | } |
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225 | |
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226 | int i386_get_idt_config (rtems_raw_irq_global_settings** config) |
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227 | { |
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228 | *config = local_settings; |
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229 | return 1; |
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230 | } |
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231 | |
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232 | uint32_t i386_raw_gdt_entry (uint16_t segment_selector_index, |
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233 | segment_descriptors* sd) |
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234 | { |
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235 | uint16_t gdt_limit; |
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236 | uint16_t tmp_segment = 0; |
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237 | segment_descriptors* gdt_entry_tbl; |
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238 | uint8_t present; |
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239 | |
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240 | i386_get_info_from_GDTR (&gdt_entry_tbl, &gdt_limit); |
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241 | |
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242 | if (segment_selector_index >= (gdt_limit+1)/8) { |
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243 | /* index to GDT table out of bounds */ |
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244 | return 0; |
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245 | } |
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246 | if (segment_selector_index == 0) { |
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247 | /* index 0 is not usable */ |
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248 | return 0; |
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249 | } |
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250 | |
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251 | /* put prepared descriptor into the GDT */ |
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252 | present = sd->present; |
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253 | sd->present = 0; |
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254 | gdt_entry_tbl[segment_selector_index].present = 0; |
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255 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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256 | gdt_entry_tbl[segment_selector_index] = *sd; |
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257 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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258 | gdt_entry_tbl[segment_selector_index].present = present; |
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259 | sd->present = present; |
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260 | /* |
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261 | * Now, reload all segment registers so that the possible changes takes effect. |
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262 | */ |
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263 | __asm__ volatile( "movw %%ds,%0 ; movw %0,%%ds\n\t" |
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264 | "movw %%es,%0 ; movw %0,%%es\n\t" |
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265 | "movw %%fs,%0 ; movw %0,%%fs\n\t" |
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266 | "movw %%gs,%0 ; movw %0,%%gs\n\t" |
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267 | "movw %%ss,%0 ; movw %0,%%ss" |
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268 | : "=r" (tmp_segment) |
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269 | : "0" (tmp_segment) |
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270 | ); |
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271 | return 1; |
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272 | } |
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273 | |
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274 | void i386_fill_segment_desc_base(uint32_t base, |
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275 | segment_descriptors* sd) |
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276 | { |
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277 | sd->base_address_15_0 = base & 0xffff; |
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278 | sd->base_address_23_16 = (base >> 16) & 0xff; |
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279 | sd->base_address_31_24 = (base >> 24) & 0xff; |
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280 | } |
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281 | |
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282 | void i386_fill_segment_desc_limit(uint32_t limit, |
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283 | segment_descriptors* sd) |
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284 | { |
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285 | sd->granularity = 0; |
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286 | if (limit > 65535) { |
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287 | sd->granularity = 1; |
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288 | limit /= 4096; |
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289 | } |
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290 | sd->limit_15_0 = limit & 0xffff; |
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291 | sd->limit_19_16 = (limit >> 16) & 0xf; |
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292 | } |
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293 | |
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294 | /* |
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295 | * Caution this function assumes the GDTR has been already set. |
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296 | */ |
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297 | uint32_t i386_set_gdt_entry (uint16_t segment_selector_index, uint32_t base, |
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298 | uint32_t limit) |
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299 | { |
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300 | segment_descriptors gdt_entry; |
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301 | memset(&gdt_entry, 0, sizeof(gdt_entry)); |
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302 | |
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303 | i386_fill_segment_desc_limit(limit, &gdt_entry); |
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304 | i386_fill_segment_desc_base(base, &gdt_entry); |
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305 | /* |
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306 | * set up descriptor type (this may well becomes a parameter if needed) |
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307 | */ |
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308 | gdt_entry.type = 2; /* Data R/W */ |
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309 | gdt_entry.descriptor_type = 1; /* Code or Data */ |
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310 | gdt_entry.privilege = 0; /* ring 0 */ |
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311 | gdt_entry.present = 1; /* not present */ |
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312 | |
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313 | /* |
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314 | * Now, reload all segment registers so the limit takes effect. |
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315 | */ |
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316 | return i386_raw_gdt_entry(segment_selector_index, &gdt_entry); |
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317 | } |
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318 | |
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319 | uint16_t i386_next_empty_gdt_entry () |
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320 | { |
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321 | uint16_t gdt_limit; |
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322 | segment_descriptors* gdt_entry_tbl; |
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323 | /* initial amount of filled descriptors */ |
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324 | static uint16_t segment_selector_index = 2; |
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325 | |
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326 | segment_selector_index += 1; |
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327 | i386_get_info_from_GDTR (&gdt_entry_tbl, &gdt_limit); |
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328 | if (segment_selector_index >= (gdt_limit+1)/8) { |
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329 | return 0; |
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330 | } |
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331 | return segment_selector_index; |
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332 | } |
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333 | |
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334 | uint16_t i386_cpy_gdt_entry(uint16_t segment_selector_index, |
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335 | segment_descriptors* struct_to_fill) |
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336 | { |
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337 | uint16_t gdt_limit; |
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338 | segment_descriptors* gdt_entry_tbl; |
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339 | |
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340 | i386_get_info_from_GDTR (&gdt_entry_tbl, &gdt_limit); |
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341 | |
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342 | if (segment_selector_index >= (gdt_limit+1)/8) { |
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343 | return 0; |
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344 | } |
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345 | |
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346 | *struct_to_fill = gdt_entry_tbl[segment_selector_index]; |
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347 | return segment_selector_index; |
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348 | } |
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349 | |
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350 | segment_descriptors* i386_get_gdt_entry(uint16_t segment_selector_index) |
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351 | { |
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352 | uint16_t gdt_limit; |
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353 | segment_descriptors* gdt_entry_tbl; |
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354 | |
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355 | i386_get_info_from_GDTR (&gdt_entry_tbl, &gdt_limit); |
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356 | |
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357 | if (segment_selector_index >= (gdt_limit+1)/8) { |
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358 | return 0; |
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359 | } |
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360 | return &gdt_entry_tbl[segment_selector_index]; |
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361 | } |
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362 | |
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363 | uint32_t i386_limit_gdt_entry(segment_descriptors* gdt_entry) |
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364 | { |
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365 | uint32_t lim = (gdt_entry->limit_15_0 + (gdt_entry->limit_19_16<<16)); |
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366 | if (gdt_entry->granularity) { |
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367 | return lim*4096+4095; |
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368 | } |
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369 | return lim; |
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370 | } |
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