Summary of FAT file system 1

                          

FAT file system summary

 
MBR : Master Boot Record (MBR)
 
DBR : DOS Boot Record (DOS boot record, partition boot sector is located)
 
BPB : BIOS Parameter Block (BIOS Parameter Block)
 
FAT : File Allocation Table (File Allocation Table)
 
Sector : Sector
 
Cluster : Cluster
 
First,  the hard disk structure
 
Below is a schematic diagram of the structure of a hard disk partition containing 4, which is divided into three primary partition and an extended partition.

 

      Summary of FAT file system 1  

Two, FAT file system structure 
 
FAT file system is composed of several parts arranged in the following sequence consisting of:
 
0 - Reserved Region
 
1 - FAT Region
 
2 - Root Directory Region (FAT32  without this part)
 
3 - File and Directory Data Region

Summary of FAT file system 1 
FAT data storage system using the small end (Little Endian) mode, it is important to note that, in using the big-endian (Big Endian) system, when the multi-byte read data must be converted, otherwise read the data is incorrect.
 
For example: a 32-bit data in the FAT 0x12345678 way to preserve as shown below:
                 Summary of FAT file system 1 
 
Third, the  main lead guide sector
 
Hard disk master boot sector = Master Boot Record (MBR) + hard disk partition table (DPT) MBR: the sector offset address 0 ~ 0x1BD 
 
DPT: offset address within the sector 0x1BE ~ 0x1FD, which is divided into four partition table:
The first partition table: 0x1BE ~ 0x1CD
The second partition table: 0x1CE ~ 0x1DD
The third partition table: 0x1DE ~ 0x1ED
The fourth partition table: 0x1EE ~ 0x1FD
Each partition table information in the table below:
 
 
 
Partition table information
 
 
 
 
 
Byte displacement
Field Length
Field names and definitions
 
 
 
 
 
0x00
BYTE
Boot Indicator (Boot Indicator), indicating whether the partition
 
Is the active partition, 0x80 = active partition, 0x00 = non-active partition
 
 
 
 
0x01
BYTE
Began to head (Starting Head)
 
 
 
 
 
0x02
6Bits
Start sector (Starting Sector), only a 0 to 5. After
 
Face two (first 6, and 7) were used to start a cylindrical field
 
 
 
 
 
 
 
 
 
 
Start cylinder (Starting Cylinder), in addition to start sector
 
0x03
10Bits
The last two fields, also the use of the cylinder to form a
 
 
 
Value. Starting Cylinder is a 10-digit maximum is 1023
 
0x04
BYTE
System ID (System ID), defines the type of partition, see
 
The following table
 
 
 
 
0x05
BYTE
The end of the head (Ending Head)
 
 
 
 
 
0x06
6Bits
End sector (Ending Sector), using only 0 to 5. Most
 
After two (6,7 bit) is used by the end of the cylindrical field
 
 
 
 
 
 
The end of the cylinder (Ending Cylinder), in addition to words ending sector
 
0x07
10Bits
The last two segments, but also the one used to form the cylindrical
 
 
 
Value. The end of the cylinder is a 10-bit number, a maximum of 1023
 
0x08
DWORD
The relative number of sectors (Relative Sectors), from the opening of the disk
 
The beginning of the partition to the beginning of the displacement amount calculated in the sector
 
 
 
 
0x0C
DWORD
The total number of sectors (Total Sectors), the partition sector total
 
Number
 
 
 
 

  

 
 
 
 
 
 
 
 
 
Type Value Partition signs and their meanings
 
 
 
 
 
 
 
 
 
 
 
Type Value
Meaning
Type Value
Meaning
 
 
 
(HEX)
(HEX)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
0
Empty. DOS or windows are not allowed
5C
Priam Edisk
 
 
 
Use shall be deemed unlawful
 
 
 
 
 
 
 
 
 
1
FAT12
61
Speed ​​Stor
 
 
 
2
XENIX root
63
GNU HURD or Sys
 
 
 
3
XENIX usr
64
Novell Netware
 
 
 
6
FAT16 partition when less than 32M
65
Novell Netware
 
 
 
0x04
 
 
 
 
 
 
 
 
 
7
HPFS / NTFS
70
Disk Secure Mult
 
 
 
8
AIX
75
PC / IX
 
 
 
9
AIX bootable
80
Old Minix
 
 
 
0A
OS / 2 Boot Manage
81
Minix / Old Linux
 
 
 
0B
Win95 FAT32
82
Linux swap
 
 
 
0C
Win95 FAT32
83
Linux
 
 
 
0E
Win95 FAT16
84
0s / 2 hidden C:
 
 
 
0F
Win95 Extended (more than 8GB)
85
Linux extended
 
 
 
10
OPUS
86
NTFS volume set
 
 
 
11
Hidden FAT12
87
NTFS volume set
 
 
 
12
Compaq diagmost
93
Amoeba
 
 
 
14
Hidden FAT16 <32MB
94
Amoeba BBT
 
 
 
16
HiddenFAT16
A0
IBM Thinkpad hidden
 
 
 
17
Hidden HPFS / NTFS
A5
BSD/386
 
 
 
18
AST Windows swap
A6
Open BSD
 
 
 
1B
Hidden FAT32
A7
NextSTEP
 
 
 
1C
Hidden FAT32 partition
B7
BSDI fs
 
 
 
(Using LBA-mode INT 13
B8
BSDI swap
 
 
 
 
extensions)
 
 
 
 
 
 
 
 
 
1E
Hidden LBA VFAT partition
BE
Solaris boot partition
 
 
 
24
NEC DOS
C0
DR-DOS/Novell DOS
 
 
 
secured partition
 
 
 
 
 
 
 
 
 
3C
Partition Magic
C1
DRDOS / sec
 
 
 
40
Venix 80286
C4
DRDOS / sec
 
 
 
41
PPC Perp Boot
C6
DRDOS / sec
 
 
 
42
NTFS Dynamic Partitions
C7
Syrinx
 
 
 
4D
QNX4.x
DB
CP / M / CTOS
 
 
 
4E
QNX4.x 2nd part
E1
DOS access
 
 
 
4F
QNX4.x 3rd part
E3
DOS r / 0
 
 
 
50
OnTrack DM
E4
Speedstor
 
 
 
51
OnTrack DM6 Aux
EB
BeoS fs
 
 
 
52
CP / M
F1
SpeedStor
 
 
 
53
OnTrack DM6 Aux
F2
DOS 3.3 + secondary
 
 
 
partition
 
 
 
 
 
 
 
 
 
54
OnTrack DM6
F4
SpeedStor
 
 
 
55
EZ-Drive
FE
LAN step
 
 
 
56
Golden Bow
FF
BBT
 
 

  

 
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