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 BOOTMENUINFO struct for detected hard disk.
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10 | ;
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11 | ; BootMenuInfo_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 BOOTMENUINFO (if successful)
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18 | ; Corrupts registers:
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19 | ; AX, BX, CX, DX, DI
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20 | ;--------------------------------------------------------------------
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21 | BootMenuInfo_CreateForHardDisk:
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22 | call BootMenuInfo_ConvertDPTtoBX ; ES:BX now points to new BOOTMENUINFO
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23 |
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24 | ; Store Drive Name
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25 | push ds ; Preserve RAMVARS
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26 | push si
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27 |
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28 | push es ; ES copied to DS
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29 | pop ds
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30 |
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31 | add si, BYTE ATA1.strModel ; DS:SI now points drive name
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32 | lea di, [bx+BOOTMENUINFO.szDrvName] ; ES:DI now points to name destination
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33 | mov cx, MAX_HARD_DISK_NAME_LENGTH / 2 ; Max number of WORDs allowed
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34 | .CopyNextWord:
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35 | lodsw
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36 | xchg al, ah ; Change endianness
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37 | stosw
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38 | loop .CopyNextWord
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39 | xor ax, ax ; Zero AX and clear CF
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40 | stosw ; Terminate with NULL
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41 |
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42 | pop si
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43 | pop ds
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44 |
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45 | ret
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46 |
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47 |
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48 | ;--------------------------------------------------------------------
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49 | ; BootMenuInfo_GetTotalSectorCount
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50 | ; Parameters:
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51 | ; DS:DI: DPT Pointer
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52 | ; Returns:
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53 | ; BX:DX:AX: 48-bit sector count
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54 | ; Corrupts registers:
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55 | ; CX
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56 | ;--------------------------------------------------------------------
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57 | ALIGN JUMP_ALIGN
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58 | BootMenuInfo_GetTotalSectorCount:
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59 | test BYTE [di+DPT.bFlagsLow], FLG_DRVNHEAD_LBA
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60 | jnz SHORT .ReturnFullCapacity
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61 | jmp AH15h_GetSectorCountToBXDXAX
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62 | .ReturnFullCapacity:
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63 | jmp AccessDPT_GetLbaSectorCountToBXDXAX
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64 |
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65 |
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66 | ;--------------------------------------------------------------------
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67 | ; Returns offset to BOOTMENUINFO based on DPT pointer.
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68 | ;
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69 | ; BootMenuInfo_ConvertDPTtoBX
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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: Offset to BOOTMENUINFO struct
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74 | ; Corrupts registers:
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75 | ; AX
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76 | ;--------------------------------------------------------------------
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77 | ALIGN JUMP_ALIGN
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78 | BootMenuInfo_ConvertDPTtoBX:
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79 | mov ax, di
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80 | sub ax, RAMVARS_size ; subtract off base of DPTs
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81 | mov bl, DPT_BOOTMENUINFO_SIZE_MULTIPLIER ; BOOTMENUINFO's are a whole number multiple of DPT size
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82 | mul bl
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83 | add ax, BOOTVARS.rgBootNfo ; add base of BOOTMENUINFO
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84 | xchg ax, bx
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85 | ret
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