_PHATVBR Struct Reference
[Volume Support]


Detailed Description

Volume boot record.

Definition at line 79 of file phatvol.h.


Data Fields

uint8_t boot_jump [3]
 Jump instruction, contains E9xxxx or EBxx90.
uint8_t boot_oem [8]
 OEM name and version.
uint16_t bios_sectsz
 Bytes per sector.
uint8_t bios_clustsz
 Sectors per cluster.
uint16_t bios_rsvd_sects
 Number of reserved sectors.
uint8_t bios_ntabs
 Number of allocation tables.
uint16_t bios_rootsz
 Number of root directory entries.
uint16_t bios_volsz
 Total number of sectors.
uint8_t bios_media
 Media descriptor.
uint16_t bios_tabsz
 Number of sectors per allocation table.
uint16_t bios_sects_p_trk
 Number of sectors per track.
uint16_t bios_heads
 Number of heads.
uint32_t bios_sects_hidd
 Number of hidden sectors.
uint32_t bios_volsz_big
 Total number of sectors for huge drives.
uint32_t bios_tabsz_big
 Number of sectors per allocation table for huge drives.
uint16_t bios_xflags
 Extended flags.
uint16_t bios_fsver
 File system version.
uint32_t bios_root_clust
 First cluster of root directory.
uint16_t bios_fsinfo
 File system info sector.
uint16_t bios_boot_bak
 Boot backup sector.
uint8_t bios_rsvd32 [12]
 Reserved for future expansion.
uint8_t boot_drive
 Logical drive number.
uint8_t boot_rsvd_nt
 Reserved field, used by Windows NT.
uint8_t boot_xsig
 Extended signature.
uint32_t boot_vol_id
 Volume serial number.
uint8_t boot_vol_lbl [11]
 Volume label.
uint8_t boot_vol_fs [8]
 File system.

Field Documentation

Jump instruction, contains E9xxxx or EBxx90.

Definition at line 81 of file phatvol.h.

Referenced by PhatDbgVbr().

OEM name and version.

Definition at line 83 of file phatvol.h.

Referenced by PhatDbgVbr().

Bytes per sector.

The BIOS parameter block starts here.

Definition at line 88 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Sectors per cluster.

Definition at line 90 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of reserved sectors.

This includes the boot sector, which is typically the only reserved sector with PHAT12/16.

Definition at line 96 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of allocation tables.

Definition at line 98 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of root directory entries.

Definition at line 100 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Total number of sectors.

Definition at line 102 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Media descriptor.

Definition at line 104 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of sectors per allocation table.

If zero, then the value is stored in bios_tabsz_big.

Definition at line 109 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of sectors per track.

Definition at line 111 of file phatvol.h.

Referenced by PhatDbgVbr().

Number of heads.

Definition at line 113 of file phatvol.h.

Referenced by PhatDbgVbr().

Number of hidden sectors.

With PHAT12 this field is two bytes only. We ignore it anyway.

Definition at line 118 of file phatvol.h.

Referenced by PhatDbgVbr().

Total number of sectors for huge drives.

Valid only if the value in bios_volsz is zero.

Definition at line 123 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of sectors per allocation table for huge drives.

This and the following 6 fields are available with PHAT32 only.

Definition at line 129 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Extended flags.

If bit 7 is set, then bits 0-3 specify the active allocation table. This feature is not yet supported. PHAT32 always updates the first two tables.

Definition at line 136 of file phatvol.h.

Referenced by PhatDbgVbr().

File system version.

Definition at line 138 of file phatvol.h.

Referenced by PhatDbgVbr().

First cluster of root directory.

Definition at line 140 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

File system info sector.

Definition at line 142 of file phatvol.h.

Referenced by PhatDbgVbr().

Boot backup sector.

Definition at line 144 of file phatvol.h.

Referenced by PhatDbgVbr().

Reserved for future expansion.

End of the BIOS parameter block.

Definition at line 149 of file phatvol.h.

Logical drive number.

With PHAT12 and PHAT16 this and the following fields are at offset 36.

Definition at line 156 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Reserved field, used by Windows NT.

Definition at line 158 of file phatvol.h.

Referenced by PhatDbgVbr().

Extended signature.

If 0x28 or 0x29, than the following fields are valid.

Definition at line 163 of file phatvol.h.

Referenced by PhatDbgVbr().

Volume serial number.

Definition at line 165 of file phatvol.h.

Referenced by PhatDbgVbr().

Volume label.

Definition at line 167 of file phatvol.h.

Referenced by PhatDbgVbr().

File system.

Definition at line 169 of file phatvol.h.

Referenced by PhatDbgVbr().


The documentation for this struct was generated from the following file:

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