| [99] | 1 | ; Project name : XTIDE Universal BIOS |
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| [3] | 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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| [99] | 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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| [3] | 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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| [99] | 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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| [3] | 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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| [99] | 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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| [3] | 40 | xor bx, bx |
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| [99] | 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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| [3] | 44 | |
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| 45 | ;-------------------------------------------------------------------- |
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| [99] | 46 | ; .GetLbaSectorCount |
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| [3] | 47 | ; Parameters: |
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| 48 | ; BX: Zero |
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| [99] | 49 | ; DS:SI: Ptr to 512-byte ATA information read from the drive |
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| [3] | 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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| [99] | 55 | .GetLbaSectorCount: |
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| 56 | test WORD [si+ATA6.wSetSup83], A6_wSetSup83_LBA48 |
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| [3] | 57 | jz SHORT .GetLba28SectorCount |
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| [99] | 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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| [3] | 62 | ret |
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| 63 | .GetLba28SectorCount: |
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| [99] | 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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| [3] | 67 | ret |
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| 68 | |
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| 69 | ;-------------------------------------------------------------------- |
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| [99] | 70 | ; .GetChsSectorCount |
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| [3] | 71 | ; Parameters: |
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| [99] | 72 | ; DS:SI: Ptr to 512-byte ATA information read from the drive |
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| [3] | 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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| [99] | 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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| [3] | 83 | ret |
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