[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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| 133 | mov dx, 10h ; First index
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| 134 |
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| 135 | .AddNextByte:
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| 136 | call CMOS_ReadFromIndexInDLtoAL
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| 137 | xor ah, ah
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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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| 141 | jbe .AddNextByte
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| 142 | ret
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