1 | ; Project name : XTIDE Universal BIOS
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2 | ; Description : Int 13h function AH=15h, Read Disk Drive Size.
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3 |
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4 | ; Section containing code
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5 | SECTION .text
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6 |
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7 | ;--------------------------------------------------------------------
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8 | ; Int 13h function AH=15h, Read Disk Drive Size.
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9 | ;
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10 | ; AH15h_HandlerForReadDiskDriveSize
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11 | ; Parameters:
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12 | ; DL: Translated Drive number
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13 | ; DS:DI: Ptr to DPT (in RAMVARS segment)
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14 | ; SS:BP: Ptr to IDEPACK
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15 | ; Returns with INTPACK:
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16 | ; If successful:
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17 | ; AH: Hard Disk: 3 (Hard disk accessible)
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18 | ; Floppy: 1 (Floppy disk, without change detection)
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19 | ; CX:DX: Total number of sectors
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20 | ; CF: 0
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21 | ; If failed:
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22 | ; AH: 0 (Drive not present)
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23 | ; CX:DX: 0
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24 | ; CF: 1
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25 | ;--------------------------------------------------------------------
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26 | ALIGN JUMP_ALIGN
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27 | AH15h_HandlerForReadDiskDriveSize:
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28 | %ifdef MODULE_SERIAL_FLOPPY
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29 | mov cl, 1 ; 1 = floppy disk, no change detection
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30 |
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31 | test dl,dl ; DO NOT store the sector count if this is a
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32 | jns .FloppyDrive ; floppy disk, some OS's depend on this not
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33 | ; happening for floppies in order to boot.
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34 | %endif
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35 |
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36 | call AH15h_GetSectorCountToBXDXAX
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37 | mov [bp+IDEPACK.intpack+INTPACK.cx], dx ; HIWORD to CX
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38 | xchg [bp+IDEPACK.intpack+INTPACK.dx], ax ; LOWORD to DX, AL gets drive number
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39 |
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40 | xor ah, ah
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41 | %ifdef MODULE_SERIAL_FLOPPY
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42 | mov cl, 3 ; 3 = Hard Disk Accessible
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43 | .FloppyDrive:
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44 |
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45 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber ; Store success to BDA and CF
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46 | mov [bp+IDEPACK.intpack+INTPACK.ah], cl
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47 | %else
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48 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH ; Store success to BDA and CF
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49 | mov BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3
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50 | %endif
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51 |
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52 | jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode
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53 |
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54 |
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55 | ;--------------------------------------------------------------------
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56 | ; AH15h_GetSectorCountFromForeignDriveToDXAX:
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57 | ; AH15h_GetSectorCountToBXDXAX:
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58 | ; Parameters:
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59 | ; DL: Drive number (AH15h_GetSectorCountFromForeignDriveToDXAX only)
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60 | ; DS: RAMVARS segment
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61 | ; DS:DI: Ptr to DPT (AH15h_GetSectorCountToDXAX only)
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62 | ; Returns:
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63 | ; DX:AX: Total sector count
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64 | ; BX: Zero
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65 | ; Corrupts registers:
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66 | ; CX
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67 | ;--------------------------------------------------------------------
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68 | AH15h_GetSectorCountFromForeignDriveToDXAX:
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69 | mov ah, GET_DRIVE_PARAMETERS
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70 | call Int13h_CallPreviousInt13hHandler
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71 | jmp SHORT ConvertAH08hReturnValuesToSectorCount
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72 |
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73 | AH15h_GetSectorCountToBXDXAX:
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74 | call AH8h_GetDriveParameters
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75 | ; Fall to ConvertAH08hReturnValuesToSectorCount
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76 |
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77 | ConvertAH08hReturnValuesToSectorCount:
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78 | call Address_ExtractLCHSparametersFromOldInt13hAddress
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79 | mov al, bh ; AL = Max head number
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80 | inc cx ; Max cylinder number to cylinder count
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81 | inc ax ; Max head number to head count (AH=8h returns max 254 so no overflow to AH)
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82 | mul bl ; AX = Head count * Sectors per track
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83 | mul cx ; DX:AX = Total sector count for AH=0xh transfer functions
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84 | xor bx, bx
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85 | ret
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