| 1 | ; File name : AccessDPT.asm
|
|---|
| 2 | ; Project name : IDE BIOS
|
|---|
| 3 | ; Created date : 16.3.2010
|
|---|
| 4 | ; Last update : 26.4.2010
|
|---|
| 5 | ; Author : Tomi Tilli
|
|---|
| 6 | ; Description : Functions for accessing DPT data.
|
|---|
| 7 |
|
|---|
| 8 | ; Section containing code
|
|---|
| 9 | SECTION .text
|
|---|
| 10 |
|
|---|
| 11 | ;--------------------------------------------------------------------
|
|---|
| 12 | ; Returns L-CHS values from DPT.
|
|---|
| 13 | ;
|
|---|
| 14 | ; AccessDPT_GetLCHSfromPCHS
|
|---|
| 15 | ; Parameters:
|
|---|
| 16 | ; DS:DI: Ptr to Disk Parameter Table
|
|---|
| 17 | ; Returns:
|
|---|
| 18 | ; AX: Number of L-CHS sectors per track
|
|---|
| 19 | ; BX: Number of L-CHS cylinders
|
|---|
| 20 | ; DX: Number of L-CHS heads
|
|---|
| 21 | ; Corrupts registers:
|
|---|
| 22 | ; Nothing
|
|---|
| 23 | ;--------------------------------------------------------------------
|
|---|
| 24 | ALIGN JUMP_ALIGN
|
|---|
| 25 | AccessDPT_GetLCHSfromPCHS:
|
|---|
| 26 | xchg ax, cx
|
|---|
| 27 | mov cl, [di+DPT.bShLtoP] ; Load shift count
|
|---|
| 28 | mov bx, [di+DPT.wPCyls] ; Load P-CHS cylinders
|
|---|
| 29 | shr bx, cl ; Shift to L-CHS cylinders
|
|---|
| 30 | xchg cx, ax
|
|---|
| 31 | mov dx, [di+DPT.wLHeads] ; Load L-CHS heads
|
|---|
| 32 | eMOVZX ax, BYTE [di+DPT.bPSect] ; Load Sectors per track
|
|---|
| 33 | ret
|
|---|
| 34 |
|
|---|
| 35 |
|
|---|
| 36 | ;--------------------------------------------------------------------
|
|---|
| 37 | ; Tests IDEVARS flags for master or slave drive.
|
|---|
| 38 | ;
|
|---|
| 39 | ; AccessDPT_TestIdeVarsFlagsForMasterOrSlaveDrive
|
|---|
| 40 | ; Parameters:
|
|---|
| 41 | ; AX: Bitmask to test DRVPARAMS.wFlags
|
|---|
| 42 | ; DS:DI: Ptr to Disk Parameter Table
|
|---|
| 43 | ; Returns:
|
|---|
| 44 | ; ZF: Set if tested bit was zero
|
|---|
| 45 | ; Cleared if tested bit was non-zero
|
|---|
| 46 | ; CF: 0
|
|---|
| 47 | ; Corrupts registers:
|
|---|
| 48 | ; BX
|
|---|
| 49 | ;--------------------------------------------------------------------
|
|---|
| 50 | ALIGN JUMP_ALIGN
|
|---|
| 51 | AccessDPT_TestIdeVarsFlagsForMasterOrSlaveDrive:
|
|---|
| 52 | call AccessDPT_GetPointerToDRVPARAMStoCSBX
|
|---|
| 53 | test [cs:bx+DRVPARAMS.wFlags], ax
|
|---|
| 54 | ret
|
|---|
| 55 |
|
|---|
| 56 | ;--------------------------------------------------------------------
|
|---|
| 57 | ; Returns pointer to DRVPARAMS for master or slave drive.
|
|---|
| 58 | ;
|
|---|
| 59 | ; AccessDPT_GetPointerToDRVPARAMStoCSBX
|
|---|
| 60 | ; Parameters:
|
|---|
| 61 | ; DS:DI: Ptr to Disk Parameter Table
|
|---|
| 62 | ; Returns:
|
|---|
| 63 | ; CS:BX: Ptr to DRVPARAMS
|
|---|
| 64 | ; Corrupts registers:
|
|---|
| 65 | ; Nothing
|
|---|
| 66 | ;--------------------------------------------------------------------
|
|---|
| 67 | ALIGN JUMP_ALIGN
|
|---|
| 68 | AccessDPT_GetPointerToDRVPARAMStoCSBX:
|
|---|
| 69 | eMOVZX bx, [di+DPT.bIdeOff] ; CS:BX points to IDEVARS
|
|---|
| 70 | test BYTE [di+DPT.bDrvSel], FLG_IDE_DRVHD_DRV
|
|---|
| 71 | jnz SHORT .ReturnPointerToSlaveDRVPARAMS
|
|---|
| 72 | add bx, BYTE IDEVARS.drvParamsMaster
|
|---|
| 73 | ret
|
|---|
| 74 | ALIGN JUMP_ALIGN
|
|---|
| 75 | .ReturnPointerToSlaveDRVPARAMS:
|
|---|
| 76 | add bx, BYTE IDEVARS.drvParamsSlave
|
|---|
| 77 | ret
|
|---|
