_PHATVBR Struct Reference

Volume boot record. More...

#include <phatvol.h>

Collaboration diagram for _PHATVBR:

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.

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Detailed Description

Volume boot record.

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Field Documentation

uint8_t _PHATVBR::boot_jump[3]

Jump instruction, contains E9xxxx or EBxx90.

Referenced by PhatDbgVbr().

uint8_t _PHATVBR::boot_oem[8]

OEM name and version.

Referenced by PhatDbgVbr().

uint16_t _PHATVBR::bios_sectsz

Bytes per sector.

The BIOS parameter block starts here.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint8_t _PHATVBR::bios_clustsz

Sectors per cluster.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_rsvd_sects

Number of reserved sectors.

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

Referenced by PhatDbgVbr(), and PhatVolMount().

uint8_t _PHATVBR::bios_ntabs

Number of allocation tables.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_rootsz

Number of root directory entries.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_volsz

Total number of sectors.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint8_t _PHATVBR::bios_media

Media descriptor.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_tabsz

Number of sectors per allocation table.

If zero, then the value is stored in bios_tabsz_big.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_sects_p_trk

Number of sectors per track.

Referenced by PhatDbgVbr().

uint16_t _PHATVBR::bios_heads

Number of heads.

Referenced by PhatDbgVbr().

uint32_t _PHATVBR::bios_sects_hidd

Number of hidden sectors.

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

Referenced by PhatDbgVbr().

uint32_t _PHATVBR::bios_volsz_big

Total number of sectors for huge drives.

Valid only if the value in bios_volsz is zero.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint32_t _PHATVBR::bios_tabsz_big

Number of sectors per allocation table for huge drives.

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

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_xflags

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.

Referenced by PhatDbgVbr().

uint16_t _PHATVBR::bios_fsver

File system version.

Referenced by PhatDbgVbr().

uint32_t _PHATVBR::bios_root_clust

First cluster of root directory.

Referenced by PhatDbgVbr(), and PhatVolMount().

uint16_t _PHATVBR::bios_fsinfo

File system info sector.

Referenced by PhatDbgVbr().

uint16_t _PHATVBR::bios_boot_bak

Boot backup sector.

Referenced by PhatDbgVbr().

uint8_t _PHATVBR::bios_rsvd32[12]

Reserved for future expansion.

End of the BIOS parameter block.

uint8_t _PHATVBR::boot_drive

Logical drive number.

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

Referenced by PhatDbgVbr(), and PhatVolMount().

uint8_t _PHATVBR::boot_rsvd_nt

Reserved field, used by Windows NT.

Referenced by PhatDbgVbr().

uint8_t _PHATVBR::boot_xsig

Extended signature.

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

Referenced by PhatDbgVbr().

uint32_t _PHATVBR::boot_vol_id

Volume serial number.

Referenced by PhatDbgVbr().

uint8_t _PHATVBR::boot_vol_lbl[11]

Volume label.

Referenced by PhatDbgVbr().

uint8_t _PHATVBR::boot_vol_fs[8]

File system.

Referenced by PhatDbgVbr().

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

• include/fs/phatvol.h