| 1 | ; Project name : XTIDE Universal BIOS
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| 2 | ; Description : Functions for accessing ATA information read with
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| 3 | ; IDENTIFY DEVICE command.
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| 4 |
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| 5 | ; Section containing code
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| 6 | SECTION .text
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| 7 |
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| 8 | ;--------------------------------------------------------------------
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| 9 | ; AtaID_GetPCHS
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| 10 | ; Parameters:
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| 11 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 12 | ; Returns:
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| 13 | ; AX: Number of user specified P-CHS cylinders
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| 14 | ; BH: Number of user specified P-CHS sectors per track
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| 15 | ; BL: Number of user specified P-CHS heads
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| 16 | ; Corrupts registers:
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| 17 | ; Nothing
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| 18 | ;--------------------------------------------------------------------
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| 19 | AtaID_GetPCHS:
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| 20 | mov ax, [es:si+ATA1.wCylCnt] ; Cylinders (1...16383)
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| 21 | mov bl, [es:si+ATA1.wHeadCnt] ; Heads (1...16)
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| 22 | mov bh, [es:si+ATA1.wSPT] ; Sectors per Track (1...63)
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| 23 | ret
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| 24 |
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| 25 |
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| 26 | ;--------------------------------------------------------------------
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| 27 | ; AtaID_GetTotalSectorCount
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| 28 | ; Parameters:
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| 29 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 30 | ; Returns:
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| 31 | ; BX:DX:AX: 48-bit sector count
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| 32 | ; Corrupts registers:
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| 33 | ; Nothing
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| 34 | ;--------------------------------------------------------------------
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| 35 | AtaID_GetTotalSectorCount:
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| 36 | push ds
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| 37 |
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| 38 | push es
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| 39 | pop ds
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| 40 | xor bx, bx
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| 41 | test WORD [si+ATA1.wCaps], A1_wCaps_LBA
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| 42 | jz SHORT .GetChsSectorCount
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| 43 | ; Fall to .GetLbaSectorCount
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| 44 |
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| 45 | ;--------------------------------------------------------------------
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| 46 | ; .GetLbaSectorCount
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| 47 | ; Parameters:
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| 48 | ; BX: Zero
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| 49 | ; DS:SI: Ptr to 512-byte ATA information read from the drive
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| 50 | ; Returns:
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| 51 | ; BX:DX:AX: 48-bit sector count
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| 52 | ; Corrupts registers:
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| 53 | ; Nothing
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| 54 | ;--------------------------------------------------------------------
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| 55 | .GetLbaSectorCount:
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| 56 | test WORD [si+ATA6.wSetSup83], A6_wSetSup83_LBA48
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| 57 | jz SHORT .GetLba28SectorCount
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| 58 | mov ax, [si+ATA6.qwLBACnt]
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| 59 | mov dx, [si+ATA6.qwLBACnt+2]
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| 60 | mov bx, [si+ATA6.qwLBACnt+4]
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| 61 | pop ds
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| 62 | ret
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| 63 | .GetLba28SectorCount:
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| 64 | mov ax, [si+ATA1.dwLBACnt]
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| 65 | mov dx, [si+ATA1.dwLBACnt+2]
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| 66 | pop ds
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| 67 | ret
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| 68 |
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| 69 | ;--------------------------------------------------------------------
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| 70 | ; .GetChsSectorCount
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| 71 | ; Parameters:
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| 72 | ; DS:SI: Ptr to 512-byte ATA information read from the drive
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| 73 | ; Returns:
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| 74 | ; DX:AX: 24-bit sector count
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| 75 | ; Corrupts registers:
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| 76 | ; Nothing
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| 77 | ;--------------------------------------------------------------------
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| 78 | .GetChsSectorCount:
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| 79 | mov al, [si+ATA1.wSPT] ; AL=Sectors per track
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| 80 | mul BYTE [si+ATA1.wHeadCnt] ; AX=Sectors per track * number of heads
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| 81 | mul WORD [si+ATA1.wCylCnt] ; DX:AX=Sectors per track * number of heads * number of cylinders
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| 82 | pop ds
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| 83 | ret
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