The boot sector
The ``boot sector'' occupies the first sector of a FAT12 and FAT16
versions of a dosfs filesystems, and the first two sectors of
a FAT32 version dosfs filesystem.
(a ``sector'' is the unit by which disk storage is read and written).
The boot sector contains the BPB (BIOS Parameter Block) and the bootstrap routine.
The BPB specifies the following parameters for the filesystem, in order:
total sectors in the filesystem
bytes per sector
sectors per cluster (a cluster is the minimum unit of allocation in
a DOS filesystem)
number of copies of the FAT (File Allocation Table)
sectors per copy of the FAT
total number or root directory entries
the media descriptor byte
sectors per track
number of heads
The last two bytes of the boot sector are always 0xaa55 and
serve as the boot sector signature.
The file allocation table
Supported versions of the DOS filesystem
© 2007 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 05 June 2007