| 1 | ; Project name : XTIDE Universal BIOS |
|---|
| 2 | ; Description : Int 13h function AH=8h, Read Disk Drive Parameters. |
|---|
| 3 | |
|---|
| 4 | ; Section containing code |
|---|
| 5 | SECTION .text |
|---|
| 6 | |
|---|
| 7 | ;-------------------------------------------------------------------- |
|---|
| 8 | ; Int 13h function AH=8h, Read Disk Drive Parameters. |
|---|
| 9 | ; |
|---|
| 10 | ; AH8h_HandlerForReadDiskDriveParameters |
|---|
| 11 | ; Parameters: |
|---|
| 12 | ; AH: Bios function 8h |
|---|
| 13 | ; DL: Drive number |
|---|
| 14 | ; Parameters loaded by Int13h_Jump: |
|---|
| 15 | ; DS: RAMVARS segment |
|---|
| 16 | ; Returns: |
|---|
| 17 | ; CH: Maximum cylinder number, bits 7...0 |
|---|
| 18 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
|---|
| 19 | ; Bits 5...0: Maximum sector number (1...63) |
|---|
| 20 | ; DH: Maximum head number (0...255) |
|---|
| 21 | ; DL: Number of drives |
|---|
| 22 | ; AH: Int 13h/40h floppy return status |
|---|
| 23 | ; CF: 0 if successfull, 1 if error |
|---|
| 24 | ; IF: 1 |
|---|
| 25 | ; Corrupts registers: |
|---|
| 26 | ; Flags |
|---|
| 27 | ;-------------------------------------------------------------------- |
|---|
| 28 | ALIGN JUMP_ALIGN |
|---|
| 29 | AH8h_HandlerForReadDiskDriveParameters: |
|---|
| 30 | call RamVars_IsDriveHandledByThisBIOS |
|---|
| 31 | jnc SHORT .GetDriveParametersForForeignHardDiskInDL |
|---|
| 32 | |
|---|
| 33 | push bx |
|---|
| 34 | call AH8h_GetDriveParameters |
|---|
| 35 | pop bx |
|---|
| 36 | jmp Int13h_ReturnWithValueInDL |
|---|
| 37 | |
|---|
| 38 | ALIGN JUMP_ALIGN |
|---|
| 39 | .GetDriveParametersForForeignHardDiskInDL: |
|---|
| 40 | call Int13h_CallPreviousInt13hHandler |
|---|
| 41 | jc SHORT .ReturnErrorFromPreviousInt13hHandler |
|---|
| 42 | call RamVars_GetCountOfKnownDrivesToDL |
|---|
| 43 | jmp Int13h_ReturnWithValueInDL |
|---|
| 44 | .ReturnErrorFromPreviousInt13hHandler: |
|---|
| 45 | jmp Int13h_PopDiDsAndReturn |
|---|
| 46 | |
|---|
| 47 | |
|---|
| 48 | ;-------------------------------------------------------------------- |
|---|
| 49 | ; Returns L-CHS parameters for drive and total hard disk count. |
|---|
| 50 | ; |
|---|
| 51 | ; AH8h_GetDriveParameters |
|---|
| 52 | ; Parameters: |
|---|
| 53 | ; DL: Drive number |
|---|
| 54 | ; DS: RAMVARS segment |
|---|
| 55 | ; Returns: |
|---|
| 56 | ; CH: Maximum cylinder number, bits 7...0 |
|---|
| 57 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
|---|
| 58 | ; Bits 5...0: Maximum sector number (1...63) |
|---|
| 59 | ; DH: Maximum head number (0...255) |
|---|
| 60 | ; DL: Number of drives |
|---|
| 61 | ; DS:DI: Ptr to DPT |
|---|
| 62 | ; AH: Int 13h/40h floppy return status |
|---|
| 63 | ; CF: 0 if successfull, 1 if error |
|---|
| 64 | ; Corrupts registers: |
|---|
| 65 | ; AL, BX |
|---|
| 66 | ;-------------------------------------------------------------------- |
|---|
| 67 | ALIGN JUMP_ALIGN |
|---|
| 68 | AH8h_GetDriveParameters: |
|---|
| 69 | call FindDPT_ForDriveNumber |
|---|
| 70 | call AccessDPT_GetLCHSfromPCHS ; AX=sectors, BX=cylinders, DX=heads |
|---|
| 71 | call AH8h_PackReturnValues |
|---|
| 72 | xor ax, ax ; Clear AH and CF |
|---|
| 73 | ret |
|---|
| 74 | |
|---|
| 75 | |
|---|
| 76 | ;-------------------------------------------------------------------- |
|---|
| 77 | ; Packs L-CHS values to INT 13h, AH=08h return values. |
|---|
| 78 | ; |
|---|
| 79 | ; AH8h_PackReturnValues |
|---|
| 80 | ; Parameters: |
|---|
| 81 | ; AX: Number of L-CHS sectors per track (1...63) |
|---|
| 82 | ; BX: Number of L-CHS cylinders available (1...1024) |
|---|
| 83 | ; DX: Number of L-CHS heads (1...256) |
|---|
| 84 | ; DS: RAMVARS segment |
|---|
| 85 | ; Returns: |
|---|
| 86 | ; CH: Maximum cylinder number, bits 7...0 |
|---|
| 87 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
|---|
| 88 | ; Bits 5...0: Maximum sector number (1...63) |
|---|
| 89 | ; DH: Maximum head number (0...255) |
|---|
| 90 | ; DL: Number of drives |
|---|
| 91 | ; Corrupts registers: |
|---|
| 92 | ; AX, BX |
|---|
| 93 | ;-------------------------------------------------------------------- |
|---|
| 94 | ALIGN JUMP_ALIGN |
|---|
| 95 | AH8h_PackReturnValues: |
|---|
| 96 | dec bx ; Cylinder count to last cylinder |
|---|
| 97 | dec dx ; Head count to max head number |
|---|
| 98 | mov dh, dl ; Max head number to DH |
|---|
| 99 | mov ch, bl ; Cylinder bits 7...0 to CH |
|---|
| 100 | mov cl, bh ; Cylinder bits 9...8 to CL |
|---|
| 101 | eROR_IM cl, 2 ; Cylinder bits 9...8 to CL bits 7...6 |
|---|
| 102 | or cl, al ; Sectors per track to CL bits 5...0 |
|---|
| 103 | jmp RamVars_GetCountOfKnownDrivesToDL |
|---|
