Structure of IA-32 IBM PC compatible MBR and partition record

Quoted from

http://en.wikipedia.org/wiki/Master_boot_record

 

Structure of a Master Boot Record

Address			Description		Size in bytes
Hex	Oct	Dec
0000	0000	0	Code Area		440 (max. 446)
01B8	0670	440	Optional Disk signature		4
01BC	0674	444	Usually Nulls; 0x0000		2
01BE	0676	446	Table of primary partitions (Four 16-byte entries, IBM Partition Table scheme)		64
01FE	0776	510	55h	MBR signature; 0xAA55[1]	2
01FF	0777	511	AAh
MBR, total size: 446 + 64 + 2 =					512

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Layout of one 16-byte partition record

Offset	Field length (bytes)	Description
0x00	1	status[7] (0x80 = bootable, 0x00 = non-bootable, other = invalid[8])
0x01	3	CHS address of first block in partition.[9] The format is described in the next 3 bytes.
0x01	1	head[10]
0x02	1	sector is in bits 5–0[11]; bits 9–8 of cylinder are in bits 7–6
0x03	1	bits 7–0 of cylinder[12]
0x04	1	partition type[13]
0x05	3	CHS address of last block in partition.[14] The format is described in the next 3 bytes.
0x05	1	head
0x06	1	sector is in bits 5–0; bits 9–8 of cylinder are in bits 7–6
0x07	1	bits 7–0 of cylinder
0x08	4	LBA of first sector in the partition
0x0C	4	number of blocks in partition, in little-endian format