.JPG)
|
GPT
header format (From Wiki)
|
||
|
Offset
|
Length
|
Contents
|
|
+0
|
8
bytes
|
Signature
("EFI PART", 45h 46h 49h 20h 50h 41h 52h 54h)
|
|
+8
|
4
bytes
|
Revision (for
GPT version 1.0 (through at least UEFI version 2.3.1), the value is 00h 00h 01h 00h)
|
|
+12
|
4
bytes
|
Header size in little endian (in bytes, usually 5Ch 00h 00h 00h meaning
92 bytes)
|
|
+16
|
4
bytes
|
CRC32 of header (offset +0 up to header
size), with this field zeroed during calculation
|
|
+20
|
4
bytes
|
Reserved; must
be zero
|
|
+24
|
8
bytes
|
Current LBA
(location of this header copy)
|
|
+32
|
8
bytes
|
Backup LBA
(location of the other header copy)
|
|
+40
|
8
bytes
|
First usable
LBA for partitions (primary partition table last LBA + 1)
|
|
+48
|
8
bytes
|
Last usable
LBA (secondary partition table first LBA - 1)
|
|
+56
|
16 bytes
|
Disk GUID
(also referred as UUID on UNIXes)
|
|
+72
|
8
bytes
|
Starting LBA
of array of partition entries (always 2 in primary copy)
|
|
+80
|
4
bytes
|
Number of
partition entries in array
|
|
+84
|
4
bytes
|
Size of a
single partition entry (usually 128)
|
|
+88
|
4
bytes
|
CRC32 of
partition array
|
|
+92
|
*
|
Reserved; must
be zeroes for the rest of the block (420 bytes for a sector size of 512
bytes; but can be more with larger sector sizes)
|
|
LBA
size
|
Total
|
|
|
GUID
partition entry format
|
||
|
Offset
|
Length
|
Contents
|
|
0
|
16 bytes
|
Partition type GUID
|
|
16
|
16 bytes
|
Unique partition GUID
|
|
32
|
8 bytes
|
First LBA (little endian)
|
|
40
|
8 bytes
|
Last LBA (inclusive,
usually odd)
|
|
48
|
8 bytes
|
Attribute flags
(e.g. bit 60 denotes read-only)
|
|
56
|
72 bytes
|
Partition name (36 UTF-16LE code units)
|
|
128
|
Total
|
|
|
Partition attributes
|
|
|
Bit
|
Content
|
|
0
|
System
partition (disk partitioning utilities must preserve the partition as is)
|
|
2
|
Legacy
BIOS bootable (equivalent to active
flag (typically bit 7 set)
at offset +0h in partition entries of the MBR partition
table)
|
|
60
|
Read-only
|
|
62
|
Hidden
|
|
63
|
Do not
automount (i.e., do not assign drive letter)
|
