1 | ; Project name : Assembly Library |
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2 | ; Description : Functions for processing characters in a string. |
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3 | |
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4 | ; Section containing code |
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5 | SECTION .text |
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6 | |
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7 | ;-------------------------------------------------------------------- |
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8 | ; Character processing callback function prototype for StringProcess_DSSIwithFunctionInDX. |
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9 | ; Parameters: |
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10 | ; AL: Character to process |
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11 | ; CX: Character number (index for next character) |
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12 | ; DS:SI: Ptr to next character |
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13 | ; BX,DI,ES: Free to use by processing function |
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14 | ; Returns: |
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15 | ; CF: Clear to continue with next character |
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16 | ; Set to stop processing |
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17 | ; BX,DI,ES: Free to use by processing function |
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18 | ; Corrupts registers: |
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19 | ; AX |
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20 | ;-------------------------------------------------------------------- |
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21 | |
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22 | |
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23 | ;-------------------------------------------------------------------- |
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24 | ; StringProcess_DSSIwithFunctionInDX |
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25 | ; Parameters: |
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26 | ; DX: Character processing function |
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27 | ; DS:SI: Ptr to NULL terminated string to convert |
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28 | ; Returns: |
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29 | ; CX: Number of characters processed |
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30 | ; CF: Clear if all characters processed |
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31 | ; Set if terminated by processing function |
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32 | ; Corrupts registers: |
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33 | ; Nothing (processing function can corrupt BX,DI,ES) |
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34 | ;-------------------------------------------------------------------- |
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35 | ALIGN JUMP_ALIGN |
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36 | StringProcess_DSSIwithFunctionInDX: |
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37 | push si |
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38 | push ax |
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39 | |
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40 | xor cx, cx |
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41 | ALIGN JUMP_ALIGN |
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42 | .ProcessNextCharacter: |
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43 | lodsb |
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44 | test al, al ; NULL to end string |
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45 | jz SHORT .EndOfString ; Return with CF cleared |
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46 | inc cx |
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47 | call dx |
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48 | jnc SHORT .ProcessNextCharacter |
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49 | |
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50 | ALIGN JUMP_ALIGN |
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51 | .EndOfString: |
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52 | pop ax |
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53 | pop si |
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54 | ret |
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55 | |
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56 | |
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57 | ;-------------------------------------------------------------------- |
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58 | ; StringProcess_ConvertToLowerCase (callback function for StringProcess_DSSIwithFunctionInDX) |
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59 | ; Parameters: |
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60 | ; AL: Character to convert to lower case |
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61 | ; DS:SI: Ptr to next character |
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62 | ; Returns: |
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63 | ; CF: Clear to continue processing |
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64 | ; Corrupts registers: |
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65 | ; AL |
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66 | ;-------------------------------------------------------------------- |
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67 | ALIGN JUMP_ALIGN |
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68 | StringProcess_ConvertToLowerCase: |
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69 | call Char_ALtoLowerCaseLetter |
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70 | mov [si-1], al |
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71 | clc |
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72 | ret |
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73 | |
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74 | |
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75 | ;-------------------------------------------------------------------- |
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76 | ; StringProcess_ConvertToWordInDIWithBaseInBX (callback function for StringProcess_DSSIwithFunctionInDX) |
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77 | ; Parameters: |
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78 | ; AL: Character to convert to lower case |
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79 | ; BX: Numeric base (2, 10 or 16) |
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80 | ; Returns: |
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81 | ; CF: Clear to continue processing |
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82 | ; Set if error |
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83 | ; Corrupts registers: |
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84 | ; AX |
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85 | ;-------------------------------------------------------------------- |
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86 | ALIGN JUMP_ALIGN |
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87 | StringProcess_ConvertToWordInDIWithBaseInBX: |
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88 | call Char_ConvertIntegerToALfromDigitInALwithBaseInBX |
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89 | cmc |
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90 | jc SHORT .InvalidCharacter |
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91 | push dx |
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92 | |
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93 | xor ah, ah ; Digit converted to integer now in AX |
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94 | xchg ax, di |
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95 | mul bx ; Old WORD *= base |
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96 | jc SHORT .Overflow |
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97 | add di, ax ; Add old WORD to new integer |
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98 | |
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99 | .Overflow: |
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100 | pop dx |
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101 | .InvalidCharacter: |
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102 | ret |
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