1 | ; Project name : Assembly Library |
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2 | ; Description : Functions for register operations. |
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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 | |
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21 | ; Section containing code |
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22 | SECTION .text |
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23 | |
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24 | ;-------------------------------------------------------------------- |
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25 | ; Math_DivQWatSSBPbyCX |
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26 | ; Parameters: |
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27 | ; [SS:BP]: 64-bit unsigned divident |
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28 | ; CX: 16-bit unsigned divisor |
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29 | ; Returns: |
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30 | ; [SS:BP]: 64-bit unsigned quotient |
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31 | ; DX: 16-bit unsigned remainder |
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32 | ; Corrupts registers: |
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33 | ; AX |
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34 | ;-------------------------------------------------------------------- |
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35 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS OR EXCLUDE_FROM_XTIDECFG |
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36 | ALIGN JUMP_ALIGN |
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37 | Math_DivQWatSSBPbyCX: |
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38 | %if 1 |
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39 | xor dx, dx |
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40 | mov ax, [bp+6] ; Load highest divident WORD to DX:AX |
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41 | div cx |
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42 | mov [bp+6], ax ; Store quotient |
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43 | |
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44 | mov ax, [bp+4] |
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45 | div cx |
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46 | mov [bp+4], ax |
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47 | |
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48 | mov ax, [bp+2] |
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49 | div cx |
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50 | mov [bp+2], ax |
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51 | |
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52 | mov ax, [bp] |
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53 | div cx |
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54 | mov [bp], ax |
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55 | ret |
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56 | %else ; ~1 |
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57 | ; This is about half the size compared to the above code but it's not tested which is why it's commented away. |
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58 | push di |
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59 | mov di, 6 |
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60 | xor dx, dx |
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61 | .Next: |
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62 | mov ax, [bp+di] |
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63 | div cx |
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64 | mov [bp+di], ax |
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65 | dec di |
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66 | dec di |
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67 | jns .Next |
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68 | pop di |
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69 | ret |
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70 | %endif ; 1 |
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71 | %endif |
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72 | |
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73 | |
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74 | ;-------------------------------------------------------------------- |
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75 | ; Math_DivDXAXbyCX |
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76 | ; Parameters: |
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77 | ; DX:AX: 32-bit unsigned divident |
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78 | ; CX: 16-bit unsigned divisor |
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79 | ; Returns: |
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80 | ; DX:AX: 32-bit unsigned quotient |
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81 | ; BX: 16-bit unsigned remainder |
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82 | ; Corrupts registers: |
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83 | ; Nothing |
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84 | ;-------------------------------------------------------------------- |
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85 | %ifndef EXCLUDE_FROM_XTIDECFG |
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86 | ALIGN JUMP_ALIGN |
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87 | Math_DivDXAXbyCX: |
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88 | xor bx, bx |
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89 | xchg bx, ax |
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90 | xchg dx, ax |
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91 | div cx |
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92 | xchg ax, bx |
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93 | div cx |
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94 | xchg dx, bx |
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95 | ret |
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96 | %endif |
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