Western Digital manual June 23 T13/2132-D Revision Initial/Default Entry, Section Header

Page 37

June 23, 2010

T13/2132-D Revision 3

7.3.4 Initial/Default Entry

Every boot catalog shall have an Initial/Default entry. This entry contains the starting address of the initial boot image. The default entry is started if the system BIOS does not have the capability to boot from other boot images in the boot catalog. Normally, a system BIOS does not check for additional boot images. If there are multiple boot image possibilities, the Initial/Default entry may be a program that has the appropriate selection mechanism for choosing the proper boot image. See Table 8 for a description of the Initial/Default Entry.

 

 

 

Table 17 — Initial/Default Entry

 

 

 

 

Offset

Type

 

Description

00h

Byte

88h - Header ID indicates a bootable image is present. 00h indicates that a

 

 

non-bootable image is present

 

 

 

01h

Byte

Boot media type. The boot image shall fall into one of three categories: Floppy,

 

 

Hard Drive, or None.

 

 

ID

Description

 

 

0

No Emulation

 

 

1

1.2MB diskette

 

 

2

1.44MB diskette

 

 

3

2.88MB diskette

 

 

4

Hard Drive

 

 

05h-FFh

Reserved

 

 

 

02-03h

Word

Load Segment. This shall be the segment address where the first emulated sector

 

 

of data is loaded into system memory. If this field cleared to zero, the default value

 

 

of 07C0h shall be used. For flat memory model architectures (such as Motorola),

 

 

this is the memory address divided by 10h.

 

 

 

04h

Byte

System type. This shall be a copy of byte 5 (system type) from the partition table

 

 

found in the boot image.

05h

Byte

Reserved

 

 

 

 

06h-07h

Word

Sector Count. This shall be the number of emulated sectors the system shall

 

 

transfer from the CD to the Load Segment address in system memory during the

 

 

boot process. This field will normally be set to 01h for 80x86 systems that are

 

 

booting a floppy or hard drive image. For No Emulation Booting, this field could

 

 

potentially ask for 32MB of data to be loaded from the CD or DVD before jumping

 

 

to the boot address.

 

 

 

08h-0Bh

DWord

Load Block. This shall be the absolute start sector on the CD or DVD of the image

 

 

to be used in the emulation.

0Ch-1Fh

Byte

Reserved

 

 

 

 

 

7.3.5 Section Header

If the CD or DVD has boot images in addition to the Initial/Default image, pointers to the images are grouped into sections. The identification string in the section header shall be used to determine if the image pointers in that section point to bootable images. If the BIOS is not setup to use a specific section as identified by the ID string, then the section shall be ignored. A good example of a section would be to identify a specific language for the

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

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Contents Revision June 23 Information technology Enhanced Disk Drive 4 EDD-4T13/2132-D Revision 3June 23 Points of ContactWorking Draft Enhanced Disk Drive 4 EDD-4 June 23 T13/2132-D Revision DraftT13/2132-D Revision June 23 American National StandardNew Capabilities added to EDD-4 Document StatusContents Working Draft Enhanced Disk Drive 4 EDD-4 Vii Viii Working Draft Enhanced Disk Drive 4 EDD-4 Output Parameters TablesFigures Introduction ForewordXii Working Draft Enhanced Disk Drive 4 EDD-4 BSR Incits ScopeAmerican National Standard for Information Technology ATA8-APT ATA8-AST Approved references Normative references GeneralApproved Ansi References Name Other references References under developmentReferences Under Development Name Project Number June 23 T13/2132-D Revision Master Boot Record MBR The first LBA on a disk Symbols and abbreviationsConventions Abbreviation MeaningLists Lists overview PrecedenceUnordered lists Ordered listsNumbering T13/2132-D Revision June 23 KeywordsInterrupt Services and Functions Register and CF ContentsNumbering conventions French English This standard Bit conventionsWord at offset n ByteDWord at word offset n QWord at word offset nATA firmware revision example ATA string byte swapping Word Byte Character in stringWord Byte ValueOverview Conventional Register Definitions 8GB INT 13h Functions Conventional FunctionsRegister Description Bit DescriptionConventional Function Definitions Function a Description Data Structure 8GB INT 13h Functions OverviewExtended Function Definitions Function DescriptionT13/2132-D Revision June 23 Device Address Packet Offset Fixed Disk Access Function Code Fixed Disk Access SubsetRemovable Media INT 13h Interface SubsetsEnhanced Disk Drive EDD Support Subset Locking and Ejecting Function CodeEDD Support Function Code ISO 9660 CD Layout Working Draft Enhanced Disk Drive 4 EDD-4 CD/DVD Boot OverviewSystem Area Unused Emulation Process Boot MethodsFloppy Boot No Emulation BootHard Drive Boot Floppy Geometries Type Cylinders Heads SectorsBoot Volume Descriptor Boot Volume Descriptor BVDCD/DVD Format Offset Type Description T13/2132-D Revision June 23 Validation EntrySection Header June 23 T13/2132-D Revision Initial/Default Entry00h Byte Header ID Type Description June 23 T13/2132-D Revision Section EntryT13/2132-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 Value Description Get Disk Type FN 15hSet Media Type FN 18h Park Heads FN 19h Identify Device Information FN 25h Interface Support Bit Map Description Check Extensions Present FN 41hExtended Read FN 42h Extended Write FN 43h Verify Sectors FN 44h Lock/Unlock Media FN 45h Eject Removable Media FN 46h Result Buffer Get Device Parameters FN 48hAscii Interface Path Definitions part 1 Host Bus Type Offset T13/2132-D Revision June 23 Interface PathDevice Path Definition00h ATA Device 01h 02h..FFh Reserved Byte Word DWord QWord Byte Port number Device parameter table extension Offset 7 READ/WRITE Multiple command block count Offset 5 Bios use only Bios use only Offset 6 IRQ numberOffset 0-1 I/O port base Offset 2-3 control port baseBit 7 32-bit transfer mode Offset 10-11 Bios selected hardware specific option flagsBit 8 Atapi device uses command packet interrupt Offset 9 PIO typeJune 23 T13/2132-D Revision Bits 9-10 translation type Bit 13h 48-bit LBA addressing enabledTranslation 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 CD Command Packet Return Boot Catalog FN 4DhHardware Configuration Sub-Functions Set Hardware Configuration FN 4EhFormatted Command Packet Offset Type Description Send Packet Command FN 50hFormatted Protocol Specific Data T13/2132-D Revision June 23 Output Parameters Security Protocol Commands FN 51h INT 15h Removable Media Eject GPT support for hybrid MBR boot code Hybrid MBR boot Hybrid MBR boot overviewAnnex a Hybrid MBR boot code EAX Hybrid MBR boot code endeavor procedureHybrid VBR boot code
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