1 | ; Project name : XTIDE Universal BIOS |
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2 | ; Description : Int 13h function AH=25h, Get Drive Information. |
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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=25h, Get Drive Information. |
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9 | ; |
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10 | ; AH25h_HandlerForGetDriveInformation |
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11 | ; Parameters: |
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12 | ; ES: Same as in INTPACK |
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13 | ; DL: Translated Drive number |
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14 | ; DS:DI: Ptr to DPT (in RAMVARS segment) |
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15 | ; SS:BP: Ptr to INTPACK |
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16 | ; Parameters on INTPACK in SS:BP: |
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17 | ; ES:BX: Ptr to buffer to receive 512-byte drive information |
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18 | ; Returns with INTPACK in SS:BP: |
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19 | ; AH: Int 13h return status |
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20 | ; CF: 0 if succesfull, 1 if error |
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21 | ;-------------------------------------------------------------------- |
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22 | ALIGN JUMP_ALIGN |
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23 | AH25h_HandlerForGetDriveInformation: |
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24 | ; Wait until previously selected drive is ready |
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25 | call HDrvSel_SelectDriveAndDisableIRQ |
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26 | jc SHORT .ReturnWithErrorCodeInAH ; Return if error |
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27 | |
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28 | ; Get drive information |
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29 | mov bx, [bp+INTPACK.bx] |
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30 | call HPIO_NormalizeDataPointer |
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31 | push bx |
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32 | mov dx, [RAMVARS.wIdeBase] ; Load base port address |
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33 | eMOVZX bx, BYTE [di+DPT.bIdeOff] ; Load offset to IDEVARS |
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34 | mov bl, [cs:bx+IDEVARS.bBusType]; Load bus type to BL |
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35 | mov bh, [di+DPT.bDrvSel] ; Load drive sel byte to BH |
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36 | pop di ; Pop buffer offset to DI |
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37 | call AH25h_GetDriveInfo ; Get drive information |
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38 | .ReturnWithErrorCodeInAH: |
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39 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH |
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40 | |
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41 | |
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42 | ;-------------------------------------------------------------------- |
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43 | ; Gets drive information using Identify Device command. |
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44 | ; |
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45 | ; AH25h_GetDriveInfo |
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46 | ; Parameters: |
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47 | ; BH: Drive Select byte for Drive and Head Select Register |
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48 | ; BL: Bus type |
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49 | ; DX: IDE Controller base port address |
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50 | ; DS: Segment to RAMVARS |
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51 | ; ES:DI: Ptr to buffer to receive 512 byte drive information |
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52 | ; Returns: |
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53 | ; AH: Int 13h return status (will be stored to BDA) |
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54 | ; CF: 0 if succesfull, 1 if error |
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55 | ; Corrupts registers: |
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56 | ; AL, CX |
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57 | ;-------------------------------------------------------------------- |
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58 | ALIGN JUMP_ALIGN |
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59 | AH25h_GetDriveInfo: |
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60 | push di |
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61 | push dx |
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62 | push bx |
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63 | |
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64 | ; Select Master or Slave drive. |
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65 | ; DO NOT WAIT UNTIL CURRENTLY SELECTED IS READY! |
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66 | ; It makes slave drive detection impossible if master is not present. |
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67 | mov [RAMVARS.wIdeBase], dx ; Store IDE Base port to RAMVARS |
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68 | add dx, BYTE REG_IDE_DRVHD ; DX to Drive and Head Sel Register |
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69 | mov al, bh ; Drive Select byte to AL |
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70 | out dx, al ; Select Master or Slave drive |
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71 | sub dx, BYTE REG_IDE_DRVHD ; Back to IDE Base port |
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72 | |
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73 | ; Wait until ready to accept commands |
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74 | xor bh, bh ; BX now contains bus type |
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75 | mov cl, B_TIMEOUT_DRVINFO ; Load short timeout |
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76 | cmp [RAMVARS.bDrvCnt], bh ; Detecting first drive? |
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77 | eCMOVE cl, B_TIMEOUT_RESET ; If so, load long timeout |
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78 | call HStatus_WaitRdy ; Wait until ready to accept commands |
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79 | jc SHORT .ReturnWithErrorCodeInAH |
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80 | |
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81 | ; Output command |
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82 | mov al, HCMD_ID_DEV ; Load Identify Device command to AL |
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83 | out dx, al ; Output command |
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84 | call HStatus_WaitDrqDefTime ; Wait until ready to transfer (no IRQ!) |
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85 | jc SHORT .ReturnWithErrorCodeInAH |
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86 | |
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87 | ; Transfer data |
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88 | sub dx, BYTE REGR_IDE_ST ; DX to IDE Data Reg |
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89 | mov cx, 256 ; Transfer 256 words (single sector) |
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90 | cld ; INSW to increment DI |
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91 | call [cs:bx+g_rgfnPioRead] ; Read ID sector |
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92 | call HStatus_WaitRdyDefTime ; Wait until drive ready |
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93 | |
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94 | .ReturnWithErrorCodeInAH: |
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95 | pop bx |
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96 | pop dx |
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97 | pop di |
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98 | ret |
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