Western Digital T13/2132-D manual Get Device Parameters FN 48h, Result Buffer

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T13/2132-D Revision 3

June 23, 2010

8.20 Get Device Parameters (FN 48h)

8.20.1 Overview

This function returns default device parameters. It shall be mandatory regardless of the interface subset that is supported. Table 22 defines the result buffer. On entry the first word of the result buffer shall be the buffer length in bytes.

Entry

AH 48h

DL BIOS device number

DS:SI Address of result buffer (see table 22)

Exit

Carry Clear Function completed without error

AH Shall be cleared to zero

DS:SI Address of result buffer (see table 22)

Carry Set Function completed with an error

AH Shall be set to the error code

 

 

 

Table 22 — Result Buffer

 

 

 

 

Offset

Type

 

Description

0

Word

The caller shall set this value to the maximum Result Buffer length, in bytes. If the

 

 

length of this buffer is less than 30 bytes, this function shall not return the pointer to

 

 

Drive Parameter Table (DPT) extension. If the buffer length is 30 or greater on entry, it

 

 

shall be set to 30 on exit. If the buffer length is between 26 and 29, it shall be set to 26

 

 

on exit. If the buffer length is less than 26 on entry an error shall be returned.

 

 

 

2

Word

Information Flags. A value of one in a bit indicates that the feature shall be available. A

 

 

value of zero in a bit indicates the feature shall be not available and shall operate in a

 

 

manner consistent with the conventional INT 13h interface.

 

 

Bit

Description

 

 

15:8

Reserved

 

 

7

BIOS calls INT13h FN 50h to access the device

 

 

6

Device geometry shall be set to maximum and no media shall be present

 

 

 

when this bit is set to one

 

 

5

Media shall be lockable

 

 

4

Device has media change notification

 

 

3

Device supports write verify

 

 

2

Media shall be removable. Bits 4-6 are not valid if this bit is cleared to zero

 

 

1

The geometry returned in bytes 4-15 shall be valid

 

 

0

DMA boundary errors are handled transparently

4

DWord

Number of default cylinders. The content of this field shall be one greater than the

 

 

maximum cylinder number. INT 13h FN 08h shall be used to find the logical number of

 

 

cylinders.

 

 

 

 

8

DWord

Number of default heads. The content of this field shall be one greater than the

 

 

maximum head number. INT 13h FN 08h shall be used to find the logical number of

 

 

heads.

 

12

DWord

Number of default sectors per track. The content of this field shall be the same as the

 

 

maximum sector number because sector addresses are 1 based. INT 13h FN 08h shall

 

 

be used to find the logical number of sectors per track.

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Working Draft Enhanced Disk Drive - 4 (EDD-4)

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Contents Information technology Enhanced Disk Drive 4 EDD-4 Revision June 23Points of Contact T13/2132-D Revision 3June 23Working Draft Enhanced Disk Drive 4 EDD-4 Draft June 23 T13/2132-D RevisionAmerican National Standard T13/2132-D Revision June 23Document Status New Capabilities added to EDD-4Contents Working Draft Enhanced Disk Drive 4 EDD-4 Vii Viii Working Draft Enhanced Disk Drive 4 EDD-4 Tables Output ParametersFigures Foreword IntroductionXii Working Draft Enhanced Disk Drive 4 EDD-4 Scope BSR IncitsAmerican National Standard for Information Technology ATA8-APT ATA8-AST Normative references General Approved referencesApproved Ansi References Name References under development Other referencesReferences Under Development Name Project Number June 23 T13/2132-D Revision Symbols and abbreviations Master Boot Record MBR The first LBA on a diskConventions Abbreviation MeaningPrecedence Lists Lists overviewUnordered lists Ordered listsT13/2132-D Revision June 23 Keywords NumberingRegister and CF Contents Interrupt Services and FunctionsNumbering conventions French English This standard Bit conventionsByte Word at offset nDWord at word offset n QWord at word offset nATA string byte swapping Word Byte Character in string ATA firmware revision exampleWord Byte ValueOverview 8GB INT 13h Functions Conventional Functions Conventional Register DefinitionsRegister Description Bit DescriptionConventional Function Definitions Function a Description 8GB INT 13h Functions Overview Data StructureExtended Function Definitions Function DescriptionT13/2132-D Revision June 23 Device Address Packet Offset Fixed Disk Access Subset Fixed Disk Access Function CodeRemovable Media INT 13h Interface SubsetsLocking and Ejecting Function Code Enhanced Disk Drive EDD Support SubsetEDD Support Function Code CD/DVD Boot Overview ISO 9660 CD Layout Working Draft Enhanced Disk Drive 4 EDD-4System Area Unused Boot Methods Emulation ProcessNo Emulation Boot Floppy BootHard Drive Boot Floppy Geometries Type Cylinders Heads SectorsBoot Volume Descriptor BVD Boot Volume DescriptorCD/DVD Format T13/2132-D Revision June 23 Validation Entry Offset Type DescriptionJune 23 T13/2132-D Revision Initial/Default Entry Section Header00h Byte Header ID June 23 T13/2132-D Revision Section Entry Type DescriptionT13/2132-D Revision June 23 Section Entry Extension INT 13h Function Definitions Overview Reset Disk Subsystem FN 00h Get Status of Last Operation FN 01h Read Sectors into Memory FN 02h Write Sectors From Memory FN 03h Verify Sectors FN 04h Get Drive Parameters FN 08h Read Buffer FN 0Eh Write Buffer FN 0Fh Get Disk Type FN 15h Value DescriptionSet Media Type FN 18h Park Heads FN 19h Identify Device Information FN 25h Check Extensions Present FN 41h Interface Support Bit Map DescriptionExtended Read FN 42h Extended Write FN 43h Verify Sectors FN 44h Lock/Unlock Media FN 45h Eject Removable Media FN 46h Get Device Parameters FN 48h Result BufferAscii T13/2132-D Revision June 23 Interface Path Interface Path Definitions part 1 Host Bus Type OffsetDefinition Device Path00h ATA Device 01h 02h..FFh Reserved Byte Word DWord QWord Byte Port number Device parameter table extension Offset 5 Bios use only Bios use only Offset 6 IRQ number Offset 7 READ/WRITE Multiple command block countOffset 0-1 I/O port base Offset 2-3 control port baseOffset 10-11 Bios selected hardware specific option flags Bit 7 32-bit transfer modeBit 8 Atapi device uses command packet interrupt Offset 9 PIO typeBit 13h 48-bit LBA addressing enabled June 23 T13/2132-D Revision Bits 9-10 translation typeTranslation Type Bits Description Bit 11 Ultra DMAGet Extended Media Change Status FN 49h Initiate Disk Emulation FN 4Ah Value Emulation Working Draft Enhanced Disk Drive 4 EDD-4 Terminate Disk Emulation FN 4Bh Initiate Disk Emulation & Boot FN 4Ch Return Boot Catalog FN 4Dh CD Command PacketSet Hardware Configuration FN 4Eh Hardware Configuration Sub-FunctionsSend Packet Command FN 50h Formatted Command Packet Offset Type DescriptionFormatted Protocol Specific Data T13/2132-D Revision June 23 Output Parameters Security Protocol Commands FN 51h INT 15h Removable Media Eject Hybrid MBR boot Hybrid MBR boot overview GPT support for hybrid MBR boot codeAnnex a Hybrid MBR boot code Hybrid MBR boot code endeavor procedure EAXHybrid VBR boot code
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