1 | ; Project name : Assembly Library
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2 | ; Description : Functions for memory access.
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3 |
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4 | ;
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5 | ; XTIDE Universal BIOS and Associated Tools
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6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
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7 | ;
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8 | ; This program is free software; you can redistribute it and/or modify
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9 | ; it under the terms of the GNU General Public License as published by
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10 | ; the Free Software Foundation; either version 2 of the License, or
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11 | ; (at your option) any later version.
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12 | ;
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13 | ; This program is distributed in the hope that it will be useful,
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14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of
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15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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16 | ; GNU General Public License for more details.
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17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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18 | ;
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19 |
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20 | ; Section containing code
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21 | SECTION .text
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22 |
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23 | ;--------------------------------------------------------------------
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24 | ; OPTIMIZE_STRING_OPERATION
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25 | ; Parameters
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26 | ; %1: Repeat instruction
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27 | ; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW)
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28 | ; CX: Number of BYTEs to operate
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29 | ; DS:SI: Ptr to source data
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30 | ; ES:DI: Ptr to destination
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31 | ; Returns:
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32 | ; SI, DI: Updated by number of bytes operated
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33 | ; Corrupts registers:
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34 | ; Nothing
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35 | ;--------------------------------------------------------------------
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36 | %macro OPTIMIZE_STRING_OPERATION 2
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37 | push cx
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38 |
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39 | shr cx, 1 ; Operate with WORDs for performance
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40 | jz %%HandleRemainingByte
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41 | %1 %2w
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42 | %%HandleRemainingByte:
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43 | jnc SHORT %%OperationCompleted
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44 | %2b
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45 |
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46 | ALIGN JUMP_ALIGN
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47 | %%OperationCompleted:
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48 | pop cx
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49 | %endmacro
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50 |
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51 |
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52 | ;--------------------------------------------------------------------
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53 | ; Memory_CopyCXbytesFromDSSItoESDI
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54 | ; Parameters
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55 | ; CX: Number of bytes to copy
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56 | ; DS:SI: Ptr to source data
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57 | ; ES:DI: Ptr to destination buffer
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58 | ; Returns:
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59 | ; SI, DI: Updated by number of bytes copied
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60 | ; Corrupts registers:
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61 | ; Nothing
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62 | ;--------------------------------------------------------------------
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63 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
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64 | ALIGN JUMP_ALIGN
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65 | Memory_CopyCXbytesFromDSSItoESDI:
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66 | OPTIMIZE_STRING_OPERATION rep, movs
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67 | ret
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68 | %endif
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69 |
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70 |
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71 | ;--------------------------------------------------------------------
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72 | ; Memory_ZeroSSBPwithSizeInCX
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73 | ; Parameters
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74 | ; CX: Number of bytes to zero
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75 | ; SS:BP: Ptr to buffer to zero
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76 | ; Returns:
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77 | ; Nothing
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78 | ; Corrupts registers:
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79 | ; Nothing
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80 | ;--------------------------------------------------------------------
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81 | %ifdef INCLUDE_MENU_LIBRARY
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82 | ALIGN JUMP_ALIGN
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83 | Memory_ZeroSSBPwithSizeInCX:
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84 | push es
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85 | push di
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86 | push ax
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87 | call Registers_CopySSBPtoESDI
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88 | call Memory_ZeroESDIwithSizeInCX
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89 | pop ax
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90 | pop di
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91 | pop es
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92 | ret
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93 | %endif
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94 |
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95 |
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96 | ;--------------------------------------------------------------------
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97 | ; Memory_ZeroESDIwithSizeInCX
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98 | ; Parameters
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99 | ; CX: Number of bytes to zero
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100 | ; ES:DI: Ptr to destination buffer
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101 | ; Returns:
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102 | ; DI: Updated by number of BYTEs stored
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103 | ; Corrupts registers:
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104 | ; AX
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105 | ;--------------------------------------------------------------------
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106 | ALIGN JUMP_ALIGN
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107 | Memory_ZeroESDIwithSizeInCX:
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108 | xor ax, ax
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109 | ; Fall to Memory_StoreCXbytesFromAccumToESDI
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110 |
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111 | ;--------------------------------------------------------------------
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112 | ; Memory_StoreCXbytesFromAccumToESDI
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113 | ; Parameters
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114 | ; AX: Word to use to fill buffer
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115 | ; CX: Number of BYTEs to store
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116 | ; ES:DI: Ptr to destination buffer
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117 | ; Returns:
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118 | ; DI: Updated by number of BYTEs stored
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119 | ; Corrupts registers:
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120 | ; Nothing
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121 | ;--------------------------------------------------------------------
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122 | ALIGN JUMP_ALIGN
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123 | Memory_StoreCXbytesFromAccumToESDI:
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124 | OPTIMIZE_STRING_OPERATION rep, stos
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125 | ret
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126 |
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127 |
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128 | ;--------------------------------------------------------------------
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129 | ; Memory_ReserveCXbytesFromStackToDSSI
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130 | ; Parameters
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131 | ; CX: Number of bytes to reserve
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132 | ; Returns:
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133 | ; DS:SI: Ptr to reserved buffer
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134 | ; Corrupts registers:
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135 | ; AX
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136 | ;--------------------------------------------------------------------
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137 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
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138 | ALIGN JUMP_ALIGN
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139 | Memory_ReserveCXbytesFromStackToDSSI:
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140 | pop ax
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141 | push ss
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142 | pop ds
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143 | sub sp, cx
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144 | mov si, sp
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145 | jmp ax
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146 | %endif
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147 |
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148 |
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149 | ;--------------------------------------------------------------------
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150 | ; Memory_SumCXbytesFromESSItoAL
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151 | ; Parameters
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152 | ; CX: Number of bytes to sum (0=65536)
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153 | ; ES:SI: Ptr to buffer containing the bytes to sum
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154 | ; Returns:
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155 | ; AL: Sum of bytes
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156 | ; ZF: Set if result is zero
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157 | ; Cleared if result is non-zero
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158 | ; Corrupts registers:
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159 | ; CX
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160 | ;--------------------------------------------------------------------
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161 | %ifndef EXCLUDE_FROM_XTIDECFG OR NO_ATAID_VALIDATION
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162 | ALIGN JUMP_ALIGN
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163 | Memory_SumCXbytesFromESSItoAL:
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164 | push si
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165 | dec si
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166 | xor al, al
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167 | ALIGN JUMP_ALIGN
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168 | .AddNextByteToAL:
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169 | inc si
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170 | add al, [es:si]
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171 | loop .AddNextByteToAL
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172 | pop si
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173 | ret
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174 | %endif
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