| 1 | ; File name : AtaID.asm |
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| 2 | ; Project name : IDE BIOS |
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| 3 | ; Created date : 6.4.2010 |
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| 4 | ; Last update : 9.4.2010 |
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| 5 | ; Author : Tomi Tilli |
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| 6 | ; Description : Functions for accessing ATA information read with |
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| 7 | ; IDENTIFY DEVICE command. |
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| 8 | |
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| 9 | ; Section containing code |
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| 10 | SECTION .text |
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| 11 | |
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| 12 | ;-------------------------------------------------------------------- |
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| 13 | ; Returns P-CHS values from ATA information. |
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| 14 | ; |
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| 15 | ; AtaID_GetPCHS |
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| 16 | ; Parameters: |
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| 17 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 18 | ; Returns: |
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| 19 | ; AX: Number of user specified P-CHS cylinders |
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| 20 | ; BL: Number of user specified P-CHS sectors per track |
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| 21 | ; BH: Number of user specified P-CHS heads |
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| 22 | ; Corrupts registers: |
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| 23 | ; Nothing |
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| 24 | ;-------------------------------------------------------------------- |
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| 25 | ALIGN JUMP_ALIGN |
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| 26 | AtaID_GetPCHS: |
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| 27 | mov ax, [es:si+ATA1.wCylCnt] ; Cylinders (1...16383) |
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| 28 | mov bh, [es:si+ATA1.wHeadCnt] ; Heads (1...16) |
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| 29 | mov bl, [es:si+ATA1.wSPT] ; Sectors per Track (1...63) |
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| 30 | ret |
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| 31 | |
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| 32 | |
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| 33 | ;-------------------------------------------------------------------- |
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| 34 | ; Returns total number of available sectors from ATA information. |
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| 35 | ; |
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| 36 | ; AtaID_GetTotalSectorCount |
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| 37 | ; Parameters: |
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| 38 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 39 | ; Returns: |
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| 40 | ; BX:DX:AX: 48-bit sector count |
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| 41 | ; Corrupts registers: |
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| 42 | ; Nothing |
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| 43 | ;-------------------------------------------------------------------- |
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| 44 | ALIGN JUMP_ALIGN |
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| 45 | AtaID_GetTotalSectorCount: |
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| 46 | xor bx, bx |
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| 47 | test WORD [es:si+ATA1.wCaps], A1_wCaps_LBA |
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| 48 | jz SHORT AtaID_GetChsSectorCount |
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| 49 | ; Fall to AtaID_GetLbaSectorCount |
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| 50 | |
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| 51 | ;-------------------------------------------------------------------- |
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| 52 | ; Returns total number of available sectors for LBA addressing. |
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| 53 | ; |
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| 54 | ; AtaID_GetLbaSectorCount |
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| 55 | ; Parameters: |
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| 56 | ; BX: Zero |
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| 57 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 58 | ; Returns: |
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| 59 | ; BX:DX:AX: 48-bit sector count |
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| 60 | ; Corrupts registers: |
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| 61 | ; Nothing |
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| 62 | ;-------------------------------------------------------------------- |
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| 63 | ;ALIGN JUMP_ALIGN |
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| 64 | AtaID_GetLbaSectorCount: |
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| 65 | test WORD [es:si+ATA6.wSetSup83], A6_wSetSup83_LBA48 |
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| 66 | jz SHORT .GetLba28SectorCount |
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| 67 | mov ax, [es:si+ATA6.qwLBACnt] |
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| 68 | mov dx, [es:si+ATA6.qwLBACnt+2] |
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| 69 | mov bx, [es:si+ATA6.qwLBACnt+4] |
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| 70 | ret |
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| 71 | ALIGN JUMP_ALIGN |
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| 72 | .GetLba28SectorCount: |
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| 73 | mov ax, [es:si+ATA1.dwLBACnt] |
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| 74 | mov dx, [es:si+ATA1.dwLBACnt+2] |
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| 75 | ret |
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| 76 | |
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| 77 | ;-------------------------------------------------------------------- |
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| 78 | ; Returns total number of available sectors for P-CHS addressing. |
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| 79 | ; |
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| 80 | ; AtaID_GetChsSectorCount |
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| 81 | ; Parameters: |
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| 82 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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| 83 | ; Returns: |
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| 84 | ; DX:AX: 24-bit sector count |
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| 85 | ; Corrupts registers: |
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| 86 | ; Nothing |
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| 87 | ;-------------------------------------------------------------------- |
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| 88 | ALIGN JUMP_ALIGN |
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| 89 | AtaID_GetChsSectorCount: |
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| 90 | mov al, [es:si+ATA1.wSPT] ; AL=Sectors per track |
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| 91 | mul BYTE [es:si+ATA1.wHeadCnt] ; AX=Sectors per track * number of heads |
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| 92 | mul WORD [es:si+ATA1.wCylCnt] ; DX:AX=Sectors per track * number of heads * number of cylinders |
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| 93 | ret |
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