MBR, disk partitioning, .... OS

最新推荐文章于 2022-03-22 16:12:00 发布

原创最新推荐文章于 2022-03-22 16:12:00 发布 · 906 阅读

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#disk #standards #structure #ibm #scheme #table

主引导记录（MBR）是硬盘等存储设备上的第一个扇区，用于存储启动信息及分区表。本文详细介绍了MBR的结构，包括代码区域、磁盘签名、分区表等内容。

A Master Boot Record (MBR), or partition sector, is the 512-byte boot sector that is the first sector ("Sector 0") of a partitioned data storage device such as a hard disk.

Due to the broad popularity of IBM PC-compatible computers, this type of MBR is widely used, to the extent of being supported by, and incorporated into, other computer types, including newer cross-platform standards for bootstrapping and partitioning.

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

Layout of one 16-byte partition record
Offset	Description
0x00	Status (0x80 = bootable, 0x00 = non-bootable, other = malformed)
0x01	(3 bytes) Cylinder-head-sector address of the first sector in the partition
0x04	( 1 byte) Partition type^[5]
0x05	(3 bytes) Cylinder-head-sector address of the last sector in the partition
0x08	(4 bytes) Logical block address of the first sector in the partition
0x0C	(4 bytes) Length of the partition, in sectors