[480] | 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : IDE Read/Write functions for transferring |
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| 3 | ; block using DMA. |
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| 4 | ; These functions should only be called from IdeTransfer.asm. |
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| 5 | |
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| 6 | ; |
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| 7 | ; XTIDE Universal BIOS and Associated Tools |
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[526] | 8 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team. |
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[480] | 9 | ; |
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| 10 | ; This program is free software; you can redistribute it and/or modify |
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| 11 | ; it under the terms of the GNU General Public License as published by |
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| 12 | ; the Free Software Foundation; either version 2 of the License, or |
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| 13 | ; (at your option) any later version. |
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| 14 | ; |
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| 15 | ; This program is distributed in the hope that it will be useful, |
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| 16 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 17 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 18 | ; GNU General Public License for more details. |
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| 19 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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| 20 | ; |
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| 21 | |
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| 22 | |
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| 23 | ; Section containing code |
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| 24 | SECTION .text |
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| 25 | |
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| 26 | ;-------------------------------------------------------------------- |
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| 27 | ; IdeDmaBlock_WriteToXTCF |
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| 28 | ; Parameters: |
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| 29 | ; CX: Block size in 512 byte sectors |
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| 30 | ; DX: XTCF Base Port Address |
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| 31 | ; ES:SI: Physical address to buffer to receive data |
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| 32 | ; Returns: |
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| 33 | ; Nothing |
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| 34 | ; Corrupts registers: |
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| 35 | ; AX, BX, CX, DX |
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| 36 | ;-------------------------------------------------------------------- |
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| 37 | ALIGN JUMP_ALIGN |
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| 38 | IdeDmaBlock_WriteToXTCF: |
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| 39 | xchg si, di |
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| 40 | mov bl, CHANNEL_3 | READ | AUTOINIT_DISABLE | ADDRESS_INCREMENT | DEMAND_MODE |
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| 41 | call TransferBlockToOrFromXTCF |
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| 42 | xchg di, si |
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| 43 | ret |
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| 44 | |
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| 45 | |
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| 46 | ;-------------------------------------------------------------------- |
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| 47 | ; IdeDmaBlock_ReadFromXTCF |
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| 48 | ; Parameters: |
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| 49 | ; CX: Block size in 512 byte sectors |
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| 50 | ; DX: XTCF Base Port Address |
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| 51 | ; ES:DI: Physical address to buffer to receive data |
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| 52 | ; Returns: |
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| 53 | ; Nothing |
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| 54 | ; Corrupts registers: |
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| 55 | ; AX, BX, CX, DX |
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| 56 | ;-------------------------------------------------------------------- |
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| 57 | ALIGN JUMP_ALIGN |
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| 58 | IdeDmaBlock_ReadFromXTCF: |
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| 59 | mov bl, CHANNEL_3 | WRITE | AUTOINIT_DISABLE | ADDRESS_INCREMENT | DEMAND_MODE |
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| 60 | ; Fall to TransferBlockToOrFromXTCF |
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| 61 | |
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| 62 | |
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| 63 | ;-------------------------------------------------------------------- |
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| 64 | ; TransferBlockToOrFromXTCF |
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| 65 | ; Parameters: |
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| 66 | ; BL: Mode byte for DMA Mode Register |
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| 67 | ; CX: Block size in 512 byte sectors |
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| 68 | ; DX: XTCF Base Port Address |
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| 69 | ; ES:DI: Physical address to buffer to receive data |
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| 70 | ; Returns: |
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| 71 | ; Nothing |
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| 72 | ; Corrupts registers: |
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| 73 | ; AX, BX, CX, DX |
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| 74 | ;-------------------------------------------------------------------- |
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| 75 | TransferBlockToOrFromXTCF: |
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[491] | 76 | ; 8-bit DMA transfers must be done within 64k physical page. |
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[486] | 77 | ; XT-CF support maximum of 64 sector (32768 bytes) blocks in DMA mode |
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| 78 | ; so we never need to separate transfer to more than 2 separate DMA operations. |
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[480] | 79 | |
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| 80 | ; Load XT-CF Control Register port to DX |
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| 81 | add dl, XTCF_CONTROL_REGISTER |
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| 82 | |
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| 83 | ; Calculate bytes for first page |
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| 84 | mov ax, di |
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| 85 | neg ax ; AX = Max BYTEs for first page |
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| 86 | %ifdef USE_186 |
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| 87 | shl cx, 9 ; CX = Block size in BYTEs |
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| 88 | %else |
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| 89 | xchg cl, ch |
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| 90 | shl cx, 1 |
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| 91 | %endif |
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| 92 | cmp cx, ax |
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| 93 | jbe SHORT .TransferLastDmaPageWithSizeInCX |
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| 94 | |
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| 95 | ; Push size for second DMA page |
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| 96 | xchg cx, ax ; CX = BYTEs for first page |
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| 97 | sub ax, cx ; AX = BYTEs for second page |
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| 98 | push ax |
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| 99 | |
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| 100 | ; Transfer first DMA page |
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| 101 | call StartDMAtransferForXTCFwithDmaModeInBL |
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| 102 | pop cx ; Pop size for second DMA page |
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| 103 | |
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| 104 | .TransferLastDmaPageWithSizeInCX: |
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| 105 | ; Fall to StartDMAtransferForXTCFwithDmaModeInBL |
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| 106 | |
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| 107 | |
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| 108 | ;-------------------------------------------------------------------- |
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| 109 | ; StartDMAtransferForXTCFwithDmaModeInBL |
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| 110 | ; Parameters: |
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[482] | 111 | ; BL: Byte for DMA Mode Register |
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[486] | 112 | ; CX: Number of BYTEs to transfer (1...32768 since max block size is limited to 64) |
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[480] | 113 | ; DX: XTCF Control Register |
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| 114 | ; Returns: |
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| 115 | ; Nothing |
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| 116 | ; Corrupts registers: |
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| 117 | ; AX |
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| 118 | ;-------------------------------------------------------------------- |
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| 119 | ALIGN JUMP_ALIGN |
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| 120 | StartDMAtransferForXTCFwithDmaModeInBL: |
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| 121 | ; Program 8-bit DMA Controller |
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| 122 | ; Disable Interrupts and DMA Channel 3 during DMA setup |
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| 123 | mov al, SET_CH3_MASK_BIT |
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| 124 | cli ; Disable interrupts |
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| 125 | out MASK_REGISTER_DMA8_out, al ; Disable DMA Channel 3 |
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| 126 | |
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| 127 | ; Set DMA Mode (read or write using channel 3) |
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| 128 | mov al, bl |
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| 129 | out MODE_REGISTER_DMA8_out, al |
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| 130 | |
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| 131 | ; Set address to DMA controller |
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| 132 | out CLEAR_FLIPFLOP_DMA8_out, al ; Reset flip-flop to low byte |
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| 133 | mov ax, es |
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| 134 | out PAGE_DMA8_CH_3, al |
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| 135 | mov ax, di |
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| 136 | out BASE_AND_CURRENT_ADDRESS_REGISTER_DMA8_CH3_out, al ; Low byte |
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| 137 | mov al, ah |
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| 138 | out BASE_AND_CURRENT_ADDRESS_REGISTER_DMA8_CH3_out, al ; High byte |
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| 139 | |
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| 140 | ; Set number of bytes to transfer (DMA controller must be programmed number of bytes - 1) |
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| 141 | mov ax, cx |
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| 142 | dec ax ; DMA controller is programmed for one byte less |
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| 143 | out BASE_AND_CURRENT_COUNT_REGISTER_DMA8_CH3_out, al ; Low byte |
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| 144 | mov al, ah |
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| 145 | out BASE_AND_CURRENT_COUNT_REGISTER_DMA8_CH3_out, al ; High byte |
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| 146 | |
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| 147 | ; Enable DMA Channel 3 |
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| 148 | mov al, CLEAR_CH3_MASK_BIT |
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| 149 | out MASK_REGISTER_DMA8_out, al ; Enable DMA Channel 3 |
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| 150 | sti ; Enable interrupts |
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| 151 | |
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| 152 | |
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[486] | 153 | %if 0 ; Slow DMA code |
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[480] | 154 | ; XT-CF transfers 16 bytes at a time. We need to manually |
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| 155 | ; start transfer for every block. |
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| 156 | ALIGN JUMP_ALIGN |
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| 157 | .TransferNextBlock: |
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| 158 | mov al, RAISE_DRQ_AND_CLEAR_XTCF_XFER_COUNTER |
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| 159 | cli ; We want no ISR to read DMA Status Register before we do |
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| 160 | out dx, al ; Transfer up to 16 bytes to/from XT-CF card |
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| 161 | ; * Here XT-CF sets CPU to wait states during transfer * |
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| 162 | in al, STATUS_REGISTER_DMA8_in |
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| 163 | sti |
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| 164 | test al, FLG_CH3_HAS_REACHED_TERMINAL_COUNT |
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| 165 | jz SHORT .TransferNextBlock ; All bytes transferred? |
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[486] | 166 | %endif ; Slow DMA code |
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[480] | 167 | |
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[486] | 168 | |
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| 169 | %if 1 ; Fast DMA code |
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| 170 | push cx |
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| 171 | add cx, BYTE 15 ; Include any partial DMA block (since we had to divide transfer to 64k physical pages) |
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| 172 | eSHR_IM cx, 4 ; Drive Block size to 16 Byte DMA Block Size |
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| 173 | |
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| 174 | .JustOneMoreDmaBlock: |
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| 175 | mov al, RAISE_DRQ_AND_CLEAR_XTCF_XFER_COUNTER |
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| 176 | ALIGN JUMP_ALIGN |
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| 177 | .TransferNextDmaBlock: |
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| 178 | out dx, al ; Transfer 16 bytes to/from XT-CF card |
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| 179 | loop .TransferNextDmaBlock |
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| 180 | |
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| 181 | inc cx ; set up CX, in case we need to do an extra iteration |
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| 182 | in al, STATUS_REGISTER_DMA8_in |
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| 183 | test al, FLG_CH3_HAS_REACHED_TERMINAL_COUNT |
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| 184 | jz SHORT .JustOneMoreDmaBlock ; it wasn't set so get more bytes |
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| 185 | pop cx |
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| 186 | %endif ; Fast DMA code |
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| 187 | |
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| 188 | |
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[480] | 189 | ; Restore XT-CF to normal operation |
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| 190 | mov al, XTCF_DMA_MODE |
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| 191 | out dx, al |
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| 192 | |
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| 193 | ; Increment physical address in ES:DI |
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| 194 | mov ax, es |
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| 195 | add di, cx |
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| 196 | adc al, ah |
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| 197 | mov es, ax |
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| 198 | ret |
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