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