Int 13/AH=48h

Prev Next Ralf Interrups Categories Contents

------

IBM/MS INT 13 Extensions - GET DRIVE PARAMETERS

AH = 48h
DL = drive (80h-FFh)
DS:SI -> buffer for drive parameters (see #00273)

Return:
CF clear if successful AH = 00h DS:SI buffer filled CF set on error AH = error code (see #00234)

BUGS: Several different Compaq BIOSes incorrectly report high-numbered drives (such as 90h, B0h, D0h, and F0h) as present, giving them the same geometry as drive 80h; as a workaround, scan through disk numbers, stopping as soon as the number of valid drives encountered equals the value in 0040h:0075h. Dell machines using PhoenixBIOS 4.0 Release 6.0 fail to correctly handle this function if the flag word at DS:[SI+2] is not 0000h on entry

See Also: AH=08h - AH=41h - AH=49h - MEM 0040h:0075h

Format of IBM/MS INT 13 Extensions drive parameters: Offset Size Description (Table 00273) 00h WORD (call) size of buffer (001Ah for v1.x, 001Eh for v2.x, 42h for v3.0) (ret) size of returned data 02h WORD information flags (see #00274) 04h DWORD number of physical cylinders on drive 08h DWORD number of physical heads on drive 0Ch DWORD number of physical sectors per track 10h QWORD total number of sectors on drive 18h WORD bytes per sector ---v2.0+ --- 1Ah DWORD -> EDD configuration parameters (see #00278) FFFFh:FFFFh if not available ---v3.0 --- 1Eh WORD signature BEDDh to indicate presence of Device Path info 20h BYTE length of Device Path information, including signature and this byte (24h for v3.0) 21h 3 BYTEs reserved (0) 24h 4 BYTEs ASCIZ name of host bus ("ISA" or "PCI") 28h 8 BYTEs ASCIZ name of interface type "ATA" "ATAPI" "SCSI" "USB" "1394" IEEE 1394 (FireWire) "FIBRE" Fibre Channel 30h 8 BYTEs Interface Path (see #00275) 38h 8 BYTEs Device Path (see #00276) 40h BYTE reserved (0) 41h BYTE checksum of bytes 1Eh-40h (two's complement of sum, which makes the 8-bit sum of bytes 1Eh-41h equal 00h)

Note: If the size is less than 30 on call, the final DWORD will not be returned by a v2.x implementation; similarly for the Device Path info

See Also: #00277 - #03196

Bitfields for IBM/MS INT 13 Extensions information flags: Bit(s) Description (Table 00274) 0 DMA boundary errors handled transparently 1 cylinder/head/sectors-per-track information is valid 2 removable drive 3 write with verify supported 4 drive has change-line support (required if drive >= 80h is removable) 5 drive can be locked (required if drive >= 80h is removable) 6 CHS information set to maximum supported values, not current media 15-7 reserved (0)

Note: Bits 4-6 are only valid if bit 2 is set

See Also: #00273

Format of EDD v3.0 Interface Path: Offset Size Description (Table 00275) ---ISA--- 00h WORD 16-bit base address 02h 6 BYTEs reserved (0) ---PCI--- 00h BYTE PCI bus number 01h BYTE PCI device number 02h BYTE PCI function number 03h 5 BYTEs reserved (0)

See Also: #00273 - #00276

Format of EDD v3.0 Device Path: Offset Size Description (Table 00276) ---ATA---

00h BYTE flag:
00h = master, 01h = slave 01h 7 BYTEs reserved (0) ---ATAPI---

00h BYTE flag:
00h = master, 01h = slave 01h BYTE logical unit number 02h 6 BYTEs reserved (0) ---SCSI--- 00h BYTE logical unit number 01h 7 BYTEs reserved (0) ---USB--- 00h BYTE to be determined 01h 7 BYTEs reserved (0) ---IEEE1394--- 00h QWORD 64-bit FireWire General Unique Identifier (GUID) ---FibreChannel--- 00h QWORD Word Wide Number (WWN)

See Also: #00273 - #00275

Format of Phoenix Enhanced Disk Drive Spec translated drive parameter table: Offset Size Description (Table 00277) 00h WORD number of cylinders 02h BYTE number of heads 03h BYTE A0h (signature indicating translated table) 04h BYTE number of physical sectors per track 05h WORD starting write precompensation cylinder number 07h BYTE reserved 08h BYTE control byte (see #03198 at INT 41"DISK 0") 09h WORD number of physical cylinders 0Bh BYTE number of physical heads 0Ch WORD cylinder number of landing zone 0Eh BYTE number of logical sectors per track 0Fh BYTE checksum

Program: The Phoenix Enhanced Disk Drive Specification is an addition to the IBM/MS INT 13 extensions

See Also: #00278 - #03196

Format of Phoenix Enhanced Disk Drive Spec Fixed Disk Parameter Table: Offset Size Description (Table 00278) 00h WORD physical I/O port base address 02h WORD disk-drive control port address 04h BYTE drive flags (see #00279) 05h BYTE proprietary information bits 7-4 reserved (0)

bits 3-0:
Phoenix proprietary (used by BIOS) 06h BYTE IRQ for drive (bits 3-0; bits 7-4 reserved and must be 0) 07h BYTE sector count for multi-sector transfers 08h BYTE DMA control

bits 7-4:
DMA type (0-2) as per ATA-2 specification

bits 3-0:
DMA channel 09h BYTE programmed I/O control

bits 7-4:
Reserved (0)

bits 3-0:
PIO type (1-4) as per ATA-2 specification 0Ah WORD drive options (see #00280) 0Ch 2 BYTEs reserved (0) 0Eh BYTE extension revision level (high nybble=major, low nybble=minor) (currently 10h for v1.0 and 11h for v1.1-3.0) 0Fh BYTE 2's complement checksum of bytes 00h-0Eh 8-bit sum of all bytes 00h-0Fh should equal 00h

Note: This structure is also called the Device Paramter Table Extension (DPTE)

See Also: #00277

Bitfields for Phoenix Enhanced Disk Drive Spec drive flags: Bit(s) Description (Table 00279) 7 reserved (1) 6 LBA enabled 5 reserved (1) 4 drive is slave 3-0 reserved (0)

See Also: #00278 - #00280

Bitfields for Phoenix Enhanced Disk Drive Spec drive options: Bit(s) Description (Table 00280) 0 fast PIO enabled 1 fast DMA access enabled 2 block PIO (multi-sector transfers) enabled 3 CHS translation enabled 4 LBA translation enabled 5 removable media 6 ATAPI device (CD-ROM) 7 32-bit transfer mode ---v1.1+ --- 8 ATAPI device uses DRQ to signal readiness for packet command. (must be 0 if bit 6 is 0) 10-9 translation type (must be 00 if bit 3 is 0). 00 Phoenix bit-shifting translation. 01 LBA-assisted translation. 10 reserved. 11 proprietary translation ---v3.0--- 11 Ultra DMA access enabled 15-12 reserved (0)

See Also: #00278 - #00279

Category: Disk I/O Enhancements - Int 13h - I

------

Prev Next Ralf Interrups Categories Contents