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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