[593] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Functions for accessing CMOS. |
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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, 2011-2018 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 | ;-------------------------------------------------------------------- |
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| 22 | ; CMOS_WriteALtoIndexInDL |
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| 23 | ; Parameters: |
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| 24 | ; AL: Byte to write |
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| 25 | ; DL: CMOS address to write to |
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| 26 | ; Returns: |
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| 27 | ; Interrupts enabled and NMI disabled |
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| 28 | ; Corrupts registers: |
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| 29 | ; Nothing |
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| 30 | ;-------------------------------------------------------------------- |
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| 31 | CMOS_WriteALtoIndexInDL: |
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| 32 | push ax |
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| 33 | call SetDLtoIndexRegister |
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| 34 | pop ax |
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| 35 | out CMOS_DATA_REGISTER, al |
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| 36 | sti |
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| 37 | ret |
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| 38 | |
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| 39 | |
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| 40 | ;-------------------------------------------------------------------- |
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| 41 | ; CMOS_ReadFromIndexInDLtoAL |
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| 42 | ; Parameters: |
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| 43 | ; DL: CMOS address to read from |
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| 44 | ; Returns: |
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| 45 | ; AL: Byte read from CMOS |
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| 46 | ; Interrupts enabled and NMI disabled |
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| 47 | ; Corrupts registers: |
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| 48 | ; Nothing |
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| 49 | ;-------------------------------------------------------------------- |
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| 50 | CMOS_ReadFromIndexInDLtoAL: |
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| 51 | call SetDLtoIndexRegister |
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| 52 | in al, CMOS_DATA_REGISTER |
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| 53 | sti |
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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 | ; SetDLtoIndexRegister |
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| 59 | ; Parameters: |
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| 60 | ; DL: CMOS address to select |
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| 61 | ; Returns: |
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| 62 | ; Interrupts disabled and NMI disabled |
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| 63 | ; Corrupts registers: |
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| 64 | ; AL |
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| 65 | ;-------------------------------------------------------------------- |
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| 66 | SetDLtoIndexRegister: |
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| 67 | mov al, dl |
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| 68 | or al, FLG_CMOS_INDEX_NMI_DISABLE ; Disable NMI |
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| 69 | cli |
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| 70 | out CMOS_INDEX_REGISTER, al |
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| 71 | ret ; Return works as I/O delay |
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| 72 | |
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| 73 | |
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| 74 | ;-------------------------------------------------------------------- |
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| 75 | ; CMOS_Verify10hTo2Dh |
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| 76 | ; Parameters: |
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| 77 | ; Nothing |
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| 78 | ; Returns: |
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| 79 | ; ZF: Set if valid checksum |
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| 80 | ; Interrupts disabled and NMI disabled |
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| 81 | ; Corrupts registers: |
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| 82 | ; AX, CX, DX |
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| 83 | ;-------------------------------------------------------------------- |
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| 84 | CMOS_Verify10hTo2Dh: |
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| 85 | ; Get checksum WORD from CMOS |
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| 86 | mov dl, CHECKSUM_OF_BYTES_10hTo2Dh_HIGH |
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| 87 | call CMOS_ReadFromIndexInDLtoAL |
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| 88 | xchg ah, al |
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| 89 | inc dx ; CHECKSUM_OF_BYTES_10hTo2Dh_LOW |
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| 90 | call CMOS_ReadFromIndexInDLtoAL |
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| 91 | push ax ; Store checksum word |
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| 92 | |
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| 93 | ; Verify checksum |
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| 94 | call GetSumOfBytes10hto2DhtoCX |
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| 95 | pop ax |
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| 96 | cmp ax, cx ; ZF set if checksum verified |
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| 97 | ret |
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| 98 | |
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| 99 | |
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| 100 | ;-------------------------------------------------------------------- |
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| 101 | ; CMOS_StoreNewChecksumFor10hto2Dh |
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| 102 | ; Parameters: |
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| 103 | ; Nothing |
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| 104 | ; Returns: |
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| 105 | ; Interrupts disabled and NMI disabled |
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| 106 | ; Corrupts registers: |
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| 107 | ; AX, CX, DX |
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| 108 | ;-------------------------------------------------------------------- |
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| 109 | CMOS_StoreNewChecksumFor10hto2Dh: |
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| 110 | call GetSumOfBytes10hto2DhtoCX |
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| 111 | |
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| 112 | ; Write it to CMOS |
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| 113 | xchg ax, cx |
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| 114 | mov dl, CHECKSUM_OF_BYTES_10hTo2Dh_LOW |
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| 115 | call CMOS_WriteALtoIndexInDL |
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| 116 | xchg al, ah |
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| 117 | dec dx ; CHECKSUM_OF_BYTES_10hTo2Dh_HIGH |
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| 118 | jmp SHORT CMOS_WriteALtoIndexInDL |
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| 119 | |
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| 120 | |
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| 121 | ;-------------------------------------------------------------------- |
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| 122 | ; GetSumOfBytes10hto2DhtoCX |
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| 123 | ; Parameters: |
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| 124 | ; Nothing |
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| 125 | ; Returns: |
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| 126 | ; CX: Sum of CMOS bytes 10h to 2Dh |
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| 127 | ; Interrupts disabled and NMI disabled |
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| 128 | ; Corrupts registers: |
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| 129 | ; AX, DX |
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| 130 | ;-------------------------------------------------------------------- |
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| 131 | GetSumOfBytes10hto2DhtoCX: |
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| 132 | xor cx, cx ; Sum |
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[601] | 133 | mov dl, 10h ; First index |
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| 134 | xor ah, ah |
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[593] | 135 | |
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| 136 | .AddNextByte: |
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| 137 | call CMOS_ReadFromIndexInDLtoAL |
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| 138 | add cx, ax |
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| 139 | inc dx |
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| 140 | cmp dl, 2Dh ; Last index |
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[601] | 141 | jbe SHORT .AddNextByte |
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[593] | 142 | ret |
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