分类: LINUX
2011-02-17 13:32:55
Address | Description | Size in bytes | |||
---|---|---|---|---|---|
Hex | Oct | Dec | |||
0000 | 0000 | 0 | code area | 440 (max. 446) | |
01B8 | 0670 | 440 | disk signature (optional) | 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 | 2 |
01FF | 0777 | 511 | AAh | ||
MBR, total size: 446 + 64 + 2 = | 512 |
Offset | Field length (bytes) | Description | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0x00 | 1 | status (0x80 = bootable (active), 0x00 = non-bootable, other = invalid ) [a] | |||||||||||||||||
0x01 | 3 | CHS address of first absolute sector in partition. [b] The format is described by 3 bytes, see the next 3 rows. | |||||||||||||||||
0x01 | 1 |
| |||||||||||||||||
0x02 | 1 |
| |||||||||||||||||
0x03 | 1 |
| |||||||||||||||||
0x04 | 1 | partition type[5][6] | |||||||||||||||||
0x05 | 3 | CHS address of last absolute sector in partition. [b] The format is described by 3 bytes, see the next 3 rows. | |||||||||||||||||
0x05 | 1 |
| |||||||||||||||||
0x06 | 1 |
| |||||||||||||||||
0x07 | 1 |
| |||||||||||||||||
0x08 | 4 | LBA of first absolute sector in the partition [e] | |||||||||||||||||
0x0C | 4 | Number of sectors in partition, in little-endian format [e] | |||||||||||||||||
Notes: ^ a Formally, status values other than 0x00 and 0x80 are undefined. ^ b Starting Sector fields are limited to 1024 cylinders, 255 heads, and 63 sectors;[citation needed] Ending Sector fields have the same limitations. ^ c The range for sector is 1 through 63; the range for cylinder is 0 through 1023; the range for head is 0 through 254 inclusive.[citation needed] ^ d The 10-bit cylinder value is split into two bytes. The value can be reassembled using this formula: cylinder = ((byte[2] & 0xc0) << 2) | byte[3] ^ e Used by OSes only in certain circumstances; in such cases the CHS addresses are ignored.[7] |