1 | /* entry.s |
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2 | * |
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3 | * This file contains the entry point for the application. |
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4 | * The name of this entry point is compiler dependent. |
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5 | * It jumps to the BSP which is responsible for performing |
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6 | * all initialization. |
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7 | * |
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8 | * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. |
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9 | * On-Line Applications Research Corporation (OAR). |
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10 | * All rights assigned to U.S. Government, 1994. |
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11 | * |
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12 | * This material may be reproduced by or for the U.S. Government pursuant |
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13 | * to the copyright license under the clause at DFARS 252.227-7013. This |
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14 | * notice must appear in all copies of this file and its derivatives. |
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15 | * |
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16 | * Based on the `gen68302' board support package, and covered by the |
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17 | * original distribution terms. |
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18 | * |
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19 | * W. Eric Norum |
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20 | * Saskatchewan Accelerator Laboratory |
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21 | * University of Saskatchewan |
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22 | * Saskatoon, Saskatchewan, CANADA |
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23 | * eric@skatter.usask.ca |
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24 | * |
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25 | * $Id$ |
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26 | */ |
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27 | |
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28 | #include "asm.h" |
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29 | |
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30 | BEGIN_CODE |
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31 | /* |
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32 | * Step 1: Decide on Reset Stack Pointer and Initial Program Counter |
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33 | */ |
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34 | Entry: |
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35 | .long SYM(m360)+1024 | 0: Initial SSP |
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36 | .long start | 1: Initial PC |
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37 | .long uhoh | 2: Bus error |
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38 | .long uhoh | 3: Address error |
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39 | .long uhoh | 4: Illegal instruction |
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40 | .long uhoh | 5: Zero division |
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41 | .long uhoh | 6: CHK, CHK2 instruction |
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42 | .long uhoh | 7: TRAPcc, TRAPV instructions |
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43 | .long uhoh | 8: Privilege violation |
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44 | .long uhoh | 9: Trace |
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45 | .long uhoh | 10: Line 1010 emulator |
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46 | .long uhoh | 11: Line 1111 emulator |
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47 | .long uhoh | 12: Hardware breakpoint |
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48 | .long uhoh | 13: Reserved for coprocessor violation |
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49 | .long uhoh | 14: Format error |
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50 | .long uhoh | 15: Uninitialized interrupt |
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51 | .long uhoh | 16: Unassigned, reserved |
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52 | .long uhoh | 17: |
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53 | .long uhoh | 18: |
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54 | .long uhoh | 19: |
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55 | .long uhoh | 20: |
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56 | .long uhoh | 21: |
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57 | .long uhoh | 22: |
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58 | .long uhoh | 23: |
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59 | .long uhoh | 24: Spurious interrupt |
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60 | .long uhoh | 25: Level 1 interrupt autovector |
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61 | .long uhoh | 26: Level 2 interrupt autovector |
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62 | .long uhoh | 27: Level 3 interrupt autovector |
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63 | .long uhoh | 28: Level 4 interrupt autovector |
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64 | .long uhoh | 29: Level 5 interrupt autovector |
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65 | .long uhoh | 30: Level 6 interrupt autovector |
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66 | .long uhoh | 31: Level 7 interrupt autovector |
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67 | .long uhoh | 32: Trap instruction (0-15) |
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68 | .long uhoh | 33: |
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69 | .long uhoh | 34: |
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70 | .long uhoh | 35: |
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71 | .long uhoh | 36: |
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72 | .long uhoh | 37: |
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73 | .long uhoh | 38: |
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74 | .long uhoh | 39: |
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75 | .long uhoh | 40: |
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76 | .long uhoh | 41: |
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77 | .long uhoh | 42: |
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78 | .long uhoh | 43: |
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79 | .long uhoh | 44: |
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80 | .long uhoh | 45: |
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81 | .long uhoh | 46: |
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82 | .long uhoh | 47: |
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83 | .long uhoh | 48: Reserved for coprocessor |
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84 | .long uhoh | 49: |
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85 | .long uhoh | 50: |
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86 | .long uhoh | 51: |
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87 | .long uhoh | 52: |
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88 | .long uhoh | 53: |
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89 | .long uhoh | 54: |
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90 | .long uhoh | 55: |
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91 | .long uhoh | 56: |
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92 | .long uhoh | 57: |
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93 | .long uhoh | 58: |
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94 | .long uhoh | 59: Unassigned, reserved |
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95 | .long uhoh | 60: |
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96 | .long uhoh | 61: |
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97 | .long uhoh | 62: |
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98 | .long uhoh | 63: |
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99 | .long uhoh | 64: User defined vectors (192) |
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100 | .long uhoh | 65: |
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101 | .long uhoh | 66: |
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102 | .long uhoh | 67: |
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103 | .long uhoh | 68: |
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104 | .long uhoh | 69: |
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105 | .long uhoh | 70: |
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106 | .long uhoh | 71: |
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107 | .long uhoh | 72: |
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108 | .long uhoh | 73: |
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109 | .long uhoh | 74: |
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110 | .long uhoh | 75: |
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111 | .long uhoh | 76: |
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112 | .long uhoh | 77: |
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113 | .long uhoh | 78: |
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114 | .long uhoh | 79: |
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115 | .long uhoh | 80: |
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116 | .long uhoh | 81: |
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117 | .long uhoh | 82: |
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118 | .long uhoh | 83: |
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119 | .long uhoh | 84: |
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120 | .long uhoh | 85: |
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121 | .long uhoh | 86: |
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122 | .long uhoh | 87: |
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123 | .long uhoh | 88: |
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124 | .long uhoh | 89: |
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125 | .long uhoh | 90: |
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126 | .long uhoh | 91: |
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127 | .long uhoh | 92: |
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128 | .long uhoh | 93: |
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129 | .long uhoh | 94: |
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130 | .long uhoh | 95: |
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131 | .long uhoh | 96: |
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132 | .long uhoh | 97: |
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133 | .long uhoh | 98: |
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134 | .long uhoh | 99: |
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135 | .long uhoh | 100: |
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136 | .long uhoh | 101: |
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137 | .long uhoh | 102: |
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138 | .long uhoh | 103: |
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139 | .long uhoh | 104: |
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140 | .long uhoh | 105: |
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141 | .long uhoh | 106: |
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142 | .long uhoh | 107: |
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143 | .long uhoh | 108: |
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144 | .long uhoh | 109: |
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145 | .long uhoh | 110: |
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146 | .long uhoh | 111: |
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147 | .long uhoh | 112: |
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148 | .long uhoh | 113: |
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149 | .long uhoh | 114: |
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150 | .long uhoh | 115: |
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151 | .long uhoh | 116: |
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152 | .long uhoh | 117: |
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153 | .long uhoh | 118: |
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154 | .long uhoh | 119: |
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155 | .long uhoh | 120: |
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156 | .long uhoh | 121: |
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157 | .long uhoh | 122: |
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158 | .long uhoh | 123: |
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159 | .long uhoh | 124: |
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160 | .long uhoh | 125: |
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161 | .long uhoh | 126: |
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162 | .long uhoh | 127: |
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163 | .long uhoh | 128: |
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164 | .long uhoh | 129: |
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165 | .long uhoh | 130: |
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166 | .long uhoh | 131: |
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167 | .long uhoh | 132: |
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168 | .long uhoh | 133: |
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169 | .long uhoh | 134: |
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170 | .long uhoh | 135: |
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171 | .long uhoh | 136: |
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172 | .long uhoh | 137: |
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173 | .long uhoh | 138: |
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174 | .long uhoh | 139: |
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175 | .long uhoh | 140: |
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176 | .long uhoh | 141: |
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177 | .long uhoh | 142: |
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178 | .long uhoh | 143: |
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179 | .long uhoh | 144: |
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180 | .long uhoh | 145: |
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181 | .long uhoh | 146: |
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182 | .long uhoh | 147: |
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183 | .long uhoh | 148: |
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184 | .long uhoh | 149: |
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185 | .long uhoh | 150: |
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186 | .long uhoh | 151: |
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187 | .long uhoh | 152: |
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188 | .long uhoh | 153: |
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189 | .long uhoh | 154: |
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190 | .long uhoh | 155: |
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191 | .long uhoh | 156: |
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192 | .long uhoh | 157: |
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193 | .long uhoh | 158: |
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194 | .long uhoh | 159: |
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195 | .long uhoh | 160: |
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196 | .long uhoh | 161: |
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197 | .long uhoh | 162: |
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198 | .long uhoh | 163: |
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199 | .long uhoh | 164: |
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200 | .long uhoh | 165: |
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201 | .long uhoh | 166: |
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202 | .long uhoh | 167: |
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203 | .long uhoh | 168: |
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204 | .long uhoh | 169: |
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205 | .long uhoh | 170: |
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206 | .long uhoh | 171: |
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207 | .long uhoh | 172: |
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208 | .long uhoh | 173: |
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209 | .long uhoh | 174: |
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210 | .long uhoh | 175: |
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211 | .long uhoh | 176: |
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212 | .long uhoh | 177: |
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213 | .long uhoh | 178: |
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214 | .long uhoh | 179: |
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215 | .long uhoh | 180: |
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216 | .long uhoh | 181: |
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217 | .long uhoh | 182: |
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218 | .long uhoh | 183: |
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219 | .long uhoh | 184: |
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220 | .long uhoh | 185: |
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221 | .long uhoh | 186: |
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222 | .long uhoh | 187: |
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223 | .long uhoh | 188: |
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224 | .long uhoh | 189: |
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225 | .long uhoh | 190: |
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226 | .long uhoh | 191: |
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227 | .long uhoh | 192: |
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228 | .long uhoh | 193: |
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229 | .long uhoh | 194: |
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230 | .long uhoh | 195: |
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231 | .long uhoh | 196: |
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232 | .long uhoh | 197: |
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233 | .long uhoh | 198: |
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234 | .long uhoh | 199: |
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235 | .long uhoh | 200: |
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236 | .long uhoh | 201: |
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237 | .long uhoh | 202: |
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238 | .long uhoh | 203: |
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239 | .long uhoh | 204: |
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240 | .long uhoh | 205: |
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241 | .long uhoh | 206: |
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242 | .long uhoh | 207: |
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243 | .long uhoh | 208: |
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244 | .long uhoh | 209: |
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245 | .long uhoh | 210: |
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246 | .long uhoh | 211: |
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247 | .long uhoh | 212: |
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248 | .long uhoh | 213: |
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249 | .long uhoh | 214: |
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250 | .long uhoh | 215: |
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251 | .long uhoh | 216: |
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252 | .long uhoh | 217: |
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253 | .long uhoh | 218: |
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254 | .long uhoh | 219: |
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255 | .long uhoh | 220: |
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256 | .long uhoh | 221: |
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257 | .long uhoh | 222: |
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258 | .long uhoh | 223: |
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259 | .long uhoh | 224: |
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260 | .long uhoh | 225: |
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261 | .long uhoh | 226: |
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262 | .long uhoh | 227: |
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263 | .long uhoh | 228: |
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264 | .long uhoh | 229: |
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265 | .long uhoh | 230: |
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266 | .long uhoh | 231: |
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267 | .long uhoh | 232: |
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268 | .long uhoh | 233: |
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269 | .long uhoh | 234: |
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270 | .long uhoh | 235: |
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271 | .long uhoh | 236: |
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272 | .long uhoh | 237: |
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273 | .long uhoh | 238: |
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274 | .long uhoh | 239: |
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275 | .long uhoh | 240: |
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276 | .long uhoh | 241: |
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277 | .long uhoh | 242: |
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278 | .long uhoh | 243: |
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279 | .long uhoh | 244: |
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280 | .long uhoh | 245: |
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281 | .long uhoh | 246: |
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282 | .long uhoh | 247: |
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283 | .long uhoh | 248: |
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284 | .long uhoh | 249: |
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285 | .long uhoh | 250: |
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286 | .long uhoh | 251: |
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287 | .long uhoh | 252: |
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288 | .long uhoh | 253: |
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289 | .long uhoh | 254: |
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290 | .long uhoh | 255: |
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291 | |
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292 | /* |
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293 | * Default trap handler |
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294 | * With an oscilloscope you can see AS* stop |
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295 | */ |
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296 | uhoh: nop | Leave spot for breakpoint |
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297 | stop #0x2700 | Stop with interrupts disabled |
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298 | bra.s uhoh | Stuck forever |
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299 | |
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300 | /* |
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301 | * Place the low-order 3 octets of the board's ethernet address at |
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302 | * a `well-known' fixed location relative to the beginning of ROM. |
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303 | */ |
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304 | .align 2 |
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305 | .long ETHERNET_ADDRESS | Low-order 3 octets of ethernet address |
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306 | |
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307 | /* |
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308 | * Initial PC |
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309 | */ |
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310 | .global start |
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311 | start: |
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312 | /* |
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313 | * Step 2: Stay in Supervisor Mode |
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314 | * (i.e. just do nothing for this step) |
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315 | */ |
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316 | |
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317 | /* |
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318 | * Step 3: Write the VBR |
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319 | */ |
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320 | lea Entry,a0 | Get base of vector table |
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321 | movec a0,vbr | Set up the VBR |
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322 | |
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323 | /* |
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324 | * Step 4: Write the MBAR |
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325 | */ |
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326 | movec dfc,d1 | Save destination register |
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327 | moveq #7,d0 | CPU-space funcction code |
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328 | movec d0,dfc | Set destination function code register |
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329 | movel #SYM(m360)+0x101,d0 | MBAR value (mask CPU space accesses) |
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330 | movesl d0,0x3FF00 | Set MBAR |
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331 | movec d1,dfc | Restore destination register |
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332 | |
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333 | /* |
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334 | * Step 5: Verify a dual-port RAM location |
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335 | */ |
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336 | lea SYM(m360),a0 | Point a0 to first DPRAM location |
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337 | moveb #0x33,d0 | Set the test value |
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338 | moveb d0,a0@ | Set the memory location |
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339 | cmpb a0@,d0 | Does it read back? |
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340 | bne uhoh | If not, bad news! |
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341 | notb d0 | Flip bits |
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342 | moveb d0,a0@ | Set the memory location |
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343 | cmpb a0@,d0 | Does it read back? |
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344 | bne uhoh | If not, bad news! |
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345 | |
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346 | /* |
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347 | * Remaining steps are handled by C code |
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348 | */ |
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349 | jmp SYM(_Init68360) | Start C code (which never returns) |
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350 | |
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351 | /* |
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352 | * Copy DATA segment, clear BSS segment, set up real stack, |
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353 | * initialize heap, start C program. |
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354 | * Assume that DATA and BSS sizes are multiples of 4. |
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355 | */ |
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356 | PUBLIC (_CopyDataClearBSSAndStart) |
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357 | SYM(_CopyDataClearBSSAndStart): |
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358 | lea copy_start,a0 | Get start of DATA in RAM |
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359 | lea SYM(etext),a2 | Get start of DATA in ROM |
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360 | cmpl a0,a2 | Are they the same? |
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361 | beq.s NOCOPY | Yes, no copy necessary |
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362 | lea copy_end,a1 | Get end of DATA in RAM |
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363 | bra.s COPYLOOPTEST | Branch into copy loop |
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364 | COPYLOOP: |
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365 | movel a2@+,a0@+ | Copy word from ROM to RAM |
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366 | COPYLOOPTEST: |
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367 | cmpl a1,a0 | Done? |
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368 | bcs.s COPYLOOP | No, skip |
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369 | NOCOPY: |
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370 | |
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371 | lea clear_start,a0 | Get start of BSS |
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372 | lea clear_end,a1 | Get end of BSS |
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373 | clrl d0 | Value to set |
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374 | bra.s ZEROLOOPTEST | Branch into clear loop |
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375 | ZEROLOOP: |
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376 | movel d0,a0@+ | Clear a word |
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377 | ZEROLOOPTEST: |
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378 | cmpl a1,a0 | Done? |
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379 | bcs.s ZEROLOOP | No, skip |
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380 | |
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381 | movel #stack_init,a7 | set master stack pointer |
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382 | movel d0,a7@- | environp |
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383 | movel d0,a7@- | argv |
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384 | movel d0,a7@- | argc |
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385 | jsr SYM(main) | Call C main |
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386 | |
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387 | | Should this just force a reset? |
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388 | mainDone: nop | Leave spot for breakpoint |
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389 | stop #0x2700 | Stop with interrupts disabled |
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390 | bra.s mainDone | Stuck forever |
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391 | |
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392 | .align 2 |
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393 | PUBLIC (_HeapSize) |
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394 | SYM (_HeapSize): |
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395 | .long HeapSize |
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396 | PUBLIC (_StackSize) |
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397 | SYM (_StackSize): |
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398 | .long StackSize |
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399 | END_CODE |
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400 | |
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401 | BEGIN_BSS |
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402 | .align 2 |
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403 | PUBLIC (environ) |
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404 | SYM (environ): |
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405 | .long 0 |
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406 | END |
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