以下资料仅供参考:
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目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
目录项(Directory Entries)
|
offset |
length |
description |
format |
comments |
|
00H |
8 bytes |
filename |
ASCII chars,or special code if first char:
00H=name never used
05H=first character or name is realy E5H
E5H=file was used,but has been erased
2EH=entry is a directory |
must be padded with spaces to fill field |
|
08H |
3 bytes |
file type(extension) |
ASCII chars |
must be padded with spaces to fill field |
|
0BH |
byte |
file attribute |
bit codes:
bit0=read-only
bit1=hidden
bit2=system
bit3=volumn label
bit4=directory
bit5=archive
bit6=unused
bit7=unused |
|
|
0CH |
10 bytes |
reserved |
|
|
|
16H |
word |
time file last updated |
coded word:(unsigned 16 bit-bit integer) time=Hr*2048+Min*32+Sec+2 |
*:least significant byte first |
|
18H |
word |
date file last updated |
coded word:(unsigned 16 bit-bit integer) time=(Yr-1980)*512+Mon*32+Day |
*:least significant byte first |
|
1AH |
word |
starting cluster number |
word binary integer* |
|
|
1CH |
dbl word |
file size |
double word binary integer* |
|
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
文件属性字节(File attribute byte)
| 7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
meaning if set to 1 |
meaning if set to 0 |
| |
|
|
|
|
|
|
v |
read-only file |
read/write file |
| |
|
|
|
|
|
v |
|
hidden file |
visible file |
| |
|
|
|
|
v |
|
|
system file |
regular file |
| |
|
|
|
v |
|
|
|
volumn name |
regular file |
| |
|
|
v |
|
|
|
|
directory name |
regular file |
| |
|
v |
|
|
|
|
|
file changed since last backup |
file unchanged since last backup |
| v |
v |
|
|
|
|
|
|
reserved |
reserved |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
FAT16结构(FAT16 structure):
|
Entry |
Example Value |
Use |
|
0 |
FFF8 |
Disk ID byte |
|
1 |
FFFF |
Filler |
|
2 |
0003 |
Cluster value:
0000 = unused cluster
0002-ffff= next cluster number
fff0-fff6= reserved cluster
fff7 = cluster marked bad
fff8-ffff= last cluster in file |
|
3 |
0004 |
|
4 |
0005 |
|
5 |
FFFF |
|
6 |
0000 |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
磁盘引导记录结构(BOOT record layout)
dos3.3 and dos4.0 BOOT record layout
| offset |
length |
description |
DOS version |
| 00 |
3 bytes |
JMP to boot code |
|
| 03 |
8 bytes |
OEM name and version |
|
| 0B |
word |
bytes per sector |
|
| 0D |
byte |
sectors per cluster(must be a power of 2) |
|
| 0E |
word |
reserved sectors(for Dir,FAT,etc.) |
|
| 10 |
byte |
Number of copies of FAT |
|
| 11 |
word |
Maximum number of root directory entries |
|
| 13 |
word |
Total number of sectors in logical image |
|
| 15 |
byte |
Media descriptor byte |
|
| 16 |
word |
number of sectors in FAT |
|
| 18 |
word |
number of sectors per track |
|
| 1A |
word |
number of heads |
|
| 1C |
word |
number of hidden sectors |
|
| 1E |
word |
HO number of hidden sectors |
|
| 20 |
dbl word |
number of logical sectors |
|
DOS5.0 BOOT sector structrure
|
offset |
length |
description |
DOS version |
|
1E |
dbl word |
number of hidden sectors |
DOS 5.0 boot sector
structure |
|
22 |
dbl word |
number of sectors if the size of the drive is larger than 32MB |
|
23 |
byte |
drive number used Internally by DOS |
|
24 |
byte |
reserved |
|
25 |
byte |
boot signature. always 29H. |
|
29 |
dbl word |
volumn ID number |
|
34 |
11 bytes |
Volumn label |
|
3C |
8 bytes |
file-system type |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
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