[3] | 1 | ; File name : HDrvSel.asm |
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| 2 | ; Project name : IDE BIOS |
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| 3 | ; Created date : 25.2.2010 |
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| 4 | ; Last update : 13.4.2010 |
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| 5 | ; Author : Tomi Tilli |
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| 6 | ; Description : Functions for selecting Master or Slave drive. |
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| 7 | |
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| 8 | ; Section containing code |
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| 9 | SECTION .text |
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| 10 | |
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| 11 | ;-------------------------------------------------------------------- |
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| 12 | ; Selects Master or Slave drive for transferring data. |
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| 13 | ; This means that interrupts will be enabled if so configured in |
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| 14 | ; IDEVARS. This function returns after drive is ready to accept commands. |
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| 15 | ; |
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| 16 | ; HDrvSel_SelectDriveForDataTransfer |
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| 17 | ; Parameters: |
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| 18 | ; DS:DI: Ptr to DPT |
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| 19 | ; Returns: |
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| 20 | ; AH: BIOS Error code |
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| 21 | ; CF: 0 if drive selected successfully |
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| 22 | ; 1 if any error |
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| 23 | ; Corrupts registers: |
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| 24 | ; AL, BX |
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| 25 | ;-------------------------------------------------------------------- |
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| 26 | ALIGN JUMP_ALIGN |
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| 27 | HDrvSel_SelectDriveForDataTransfer: |
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| 28 | mov al, [di+DPT.bDrvCtrl] ; Load Device Control Byte |
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| 29 | ; Fall to HDrvSel_SelectDriveAndSetControlByte |
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| 30 | |
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| 31 | ;-------------------------------------------------------------------- |
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| 32 | ; Selects Master or Slave drive. |
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| 33 | ; Device Control Byte can be used to enable or disable interrupts. |
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| 34 | ; This function returns only after drive is ready to accept commands. |
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| 35 | ; |
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| 36 | ; HDrvSel_SelectDriveAndSetControlByte |
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| 37 | ; Parameters: |
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| 38 | ; AL: Device Control Byte (to enable/disable interrupts) |
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| 39 | ; DS:DI: Ptr to DPT |
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| 40 | ; Returns: |
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| 41 | ; AH: BIOS Error code |
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| 42 | ; CF: 0 if drive selected successfully |
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| 43 | ; 1 if any error |
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| 44 | ; Corrupts registers: |
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| 45 | ; AL, BX |
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| 46 | ;-------------------------------------------------------------------- |
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| 47 | ;ALIGN JUMP_ALIGN |
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| 48 | HDrvSel_SelectDriveAndSetControlByte: |
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| 49 | push dx |
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| 50 | push cx |
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| 51 | |
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| 52 | ; Output Device Control Register to enable/disable interrupts |
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| 53 | call HDrvSel_OutputDeviceControlByte |
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| 54 | |
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| 55 | ; Select Master or Slave drive |
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| 56 | mov dx, [RAMVARS.wIdeBase] |
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| 57 | add dx, BYTE REG_IDE_DRVHD |
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| 58 | mov al, [di+DPT.bDrvSel] ; Load Master/Slave selection byte |
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| 59 | out dx, al ; Select drive |
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| 60 | |
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| 61 | ; Wait until drive is ready to accept commands |
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| 62 | call SoftDelay_BeforePollingStatusRegister |
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| 63 | call HStatus_WaitRdyDefTime |
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| 64 | pop cx |
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| 65 | pop dx |
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| 66 | ret |
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| 67 | |
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| 68 | |
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| 69 | ;-------------------------------------------------------------------- |
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| 70 | ; Outputs Device Control Byte to Device Control Register. |
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| 71 | ; |
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| 72 | ; HDrvSel_OutputDeviceControlByte |
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| 73 | ; Parameters: |
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| 74 | ; AL: Device Control Byte |
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| 75 | ; DS:DI: Ptr to Disk Parameter Table |
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| 76 | ; Returns: |
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| 77 | ; DX: Device Control Register address |
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| 78 | ; Corrupts registers: |
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| 79 | ; BX |
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| 80 | ;-------------------------------------------------------------------- |
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| 81 | ALIGN JUMP_ALIGN |
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| 82 | HDrvSel_OutputDeviceControlByte: |
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| 83 | eMOVZX bx, BYTE [di+DPT.bIdeOff] ; CS:BX now points to IDEVARS |
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| 84 | mov dx, [cs:bx+IDEVARS.wPortCtrl] ; Load Control Block base address |
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| 85 | add dx, BYTE REGW_IDEC_CTRL ; Add offset to Device Control Register |
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| 86 | out dx, al ; Output Device Control byte |
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| 87 | ret |
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| 88 | |
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| 89 | |
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| 90 | ;-------------------------------------------------------------------- |
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| 91 | ; Selects Master or Slave drive and disables interrupts. Interrupts should |
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| 92 | ; be disabled for commands that do not transfer data. |
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| 93 | ; This function returns after drive is ready to accept commands. |
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| 94 | ; |
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| 95 | ; HDrvSel_SelectDriveAndDisableIRQ |
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| 96 | ; Parameters: |
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| 97 | ; DS:DI: Ptr to DPT |
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| 98 | ; Returns: |
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| 99 | ; AH: BIOS Error code |
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| 100 | ; CF: 0 if drive selected successfully |
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| 101 | ; 1 if any error |
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| 102 | ; Corrupts registers: |
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| 103 | ; AL |
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| 104 | ;-------------------------------------------------------------------- |
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| 105 | ALIGN JUMP_ALIGN |
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| 106 | HDrvSel_SelectDriveAndDisableIRQ: |
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| 107 | push bx |
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| 108 | mov al, [di+DPT.bDrvCtrl] ; Load Device Control Byte |
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| 109 | or al, FLG_IDE_CTRL_nIEN ; Disable interrupts |
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| 110 | call HDrvSel_SelectDriveAndSetControlByte |
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| 111 | pop bx |
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| 112 | ret |
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