1 | ; Project name : XTIDE Universal BIOS |
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2 | ; Description : Functions for generating and accessing drive |
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3 | ; information to be displayed on boot menu. |
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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 | ; Creates new BOOTNFO struct for detected hard disk. |
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10 | ; |
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11 | ; BootInfo_CreateForHardDisk |
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12 | ; Parameters: |
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13 | ; DL: Drive number |
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14 | ; DS:DI: Ptr to Disk Parameter Table |
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15 | ; ES:SI: Ptr to 512-byte ATA information read from the drive |
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16 | ; Returns: |
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17 | ; ES:BX: Ptr to BOOTNFO (if successful) |
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18 | ; Corrupts registers: |
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19 | ; AX, BX, CX, DX, DI, SI |
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20 | ;-------------------------------------------------------------------- |
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21 | BootInfo_CreateForHardDisk: |
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22 | call BootInfo_ConvertDPTtoBX ; ES:BX now points to new BOOTNFO |
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23 | push bx ; Preserve for return |
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24 | |
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25 | mov di, bx ; Starting pointer at beginning of structure |
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26 | |
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27 | ; |
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28 | ; Store Drive Name |
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29 | ; |
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30 | push ds ; Preserve RAMVARS |
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31 | push si ; Preserve SI for call to GetTotalSectorCount... |
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32 | |
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33 | push es ; ES copied to DS |
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34 | pop ds |
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35 | |
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36 | add si, BYTE ATA1.strModel ; DS:SI now points drive name |
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37 | lea di, [bx+BOOTNFO.szDrvName] ; ES:DI now points to name destination |
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38 | mov cx, LEN_BOOTNFO_DRV / 2 ; Max number of WORDs allowed |
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39 | .CopyNextWord: |
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40 | lodsw |
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41 | xchg al, ah ; Change endianness |
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42 | stosw |
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43 | loop .CopyNextWord |
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44 | xor ax, ax ; Zero AX and clear CF |
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45 | stosw ; Terminate with NULL |
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46 | |
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47 | pop si |
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48 | pop ds |
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49 | |
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50 | ; |
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51 | ; Store Sector Count |
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52 | ; |
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53 | call AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI |
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54 | |
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55 | stosw |
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56 | xchg ax, dx |
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57 | stosw |
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58 | xchg ax, bx |
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59 | stosw |
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60 | |
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61 | pop bx |
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62 | |
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63 | ret |
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64 | |
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65 | |
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66 | ;-------------------------------------------------------------------- |
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67 | ; Finds BOOTNFO for drive and returns total sector count. |
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68 | ; |
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69 | ; BootInfo_GetTotalSectorCount |
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70 | ; Parameters: |
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71 | ; DS:DI: DPT Pointer |
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72 | ; Returns: |
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73 | ; BX:DX:AX: 48-bit sector count |
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74 | ; Corrupts registers: |
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75 | ; Nothing |
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76 | ;-------------------------------------------------------------------- |
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77 | ALIGN JUMP_ALIGN |
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78 | BootInfo_GetTotalSectorCount: |
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79 | push ds |
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80 | call BootInfo_ConvertDPTtoBX |
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81 | LOAD_BDA_SEGMENT_TO ds, ax |
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82 | mov ax, [bx+BOOTNFO.twSectCnt] |
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83 | mov dx, [bx+BOOTNFO.twSectCnt+2] |
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84 | mov bx, [bx+BOOTNFO.twSectCnt+4] |
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85 | pop ds |
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86 | ret |
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87 | |
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88 | |
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89 | ;-------------------------------------------------------------------- |
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90 | ; Returns offset to BOOTNFO based on DPT pointer. |
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91 | ; |
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92 | ; BootInfo_ConvertDPTtoBX |
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93 | ; Parameters: |
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94 | ; DS:DI: DPT Pointer |
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95 | ; Returns: |
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96 | ; BX: Offset to BOOTNFO struct |
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97 | ; Corrupts registers: |
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98 | ; AX |
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99 | ;-------------------------------------------------------------------- |
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100 | ALIGN JUMP_ALIGN |
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101 | BootInfo_ConvertDPTtoBX: |
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102 | mov ax, di |
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103 | sub ax, RAMVARS_size ; subtract off base of DPTs |
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104 | mov bl, DPT_BOOTNFO_SIZE_MULTIPLIER ; BOOTNFO's are a whole number multiple of DPT size |
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105 | mul bl |
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106 | add ax, BOOTVARS.rgBootNfo ; add base of BOOTNFO |
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107 | xchg ax, bx |
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108 | ret |
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