_PHATVBR Struct Reference
[Volume Support]


Detailed Description

Volume boot record.

Definition at line 76 of file phatvol.h.


Data Fields

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

Field Documentation

Jump instruction, contains E9xxxx or EBxx90.

Definition at line 78 of file phatvol.h.

Referenced by PhatDbgVbr().

OEM name and version.

Definition at line 80 of file phatvol.h.

Referenced by PhatDbgVbr().

Bytes per sector.

The BIOS parameter block starts here.

Definition at line 85 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Sectors per cluster.

Definition at line 87 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 93 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of allocation tables.

Definition at line 95 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of root directory entries.

Definition at line 97 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Total number of sectors.

Definition at line 99 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Media descriptor.

Definition at line 101 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 106 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Number of sectors per track.

Definition at line 108 of file phatvol.h.

Referenced by PhatDbgVbr().

Number of heads.

Definition at line 110 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 115 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 120 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 126 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 133 of file phatvol.h.

Referenced by PhatDbgVbr().

File system version.

Definition at line 135 of file phatvol.h.

Referenced by PhatDbgVbr().

First cluster of root directory.

Definition at line 137 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

File system info sector.

Definition at line 139 of file phatvol.h.

Referenced by PhatDbgVbr().

Boot backup sector.

Definition at line 141 of file phatvol.h.

Referenced by PhatDbgVbr().

Reserved for future expansion.

End of the BIOS parameter block.

Definition at line 146 of file phatvol.h.

Logical drive number.

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

Definition at line 153 of file phatvol.h.

Referenced by PhatDbgVbr(), and PhatVolMount().

Reserved field, used by Windows NT.

Definition at line 155 of file phatvol.h.

Referenced by PhatDbgVbr().

Extended signature.

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

Definition at line 160 of file phatvol.h.

Referenced by PhatDbgVbr().

Volume serial number.

Definition at line 162 of file phatvol.h.

Referenced by PhatDbgVbr().

Volume label.

Definition at line 164 of file phatvol.h.

Referenced by PhatDbgVbr().

File system.

Definition at line 166 of file phatvol.h.

Referenced by PhatDbgVbr().


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

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