请教关于mbr中的内容和/boot/grub中stage1的内容差异问题

lionfun

我在看到http://blogimg.chinaunix.net/blog/upfile2/081003000156.pdf的时候，里面有这么一句话：如果你安装grub 到mbr，grub 的安装程序会把stage1（512B）拷贝到mbr
但是当我查看当前的mbr和stage1的内容的时候发现有差别，具体如下：我首先通过dd命令将当前的MBR（512B）拷贝到mbr.img中，然后通过hexdump命令查看后10行，看到标有红色的地方有区别，我不太明白，同为前446字节的内容，为啥就这个地方不一样呢？
root@server grub]# hexdump -C stage1 | tail -10
00000170  06 be 94 7d e8 30 00 be  99 7d e8 2a 00 eb fe 47  |...}.0...}.*...G|
00000180  52 55 42 20 00 47 65 6f  6d 00 48 61 72 64 20 44  |RUB .Geom.Hard D|
00000190  69 73 6b 00 52 65 61 64  00 20 45 72 72 6f 72 00  |isk.Read. Error.|
000001a0  bb 01 00 b4 0e cd 10 ac  3c 00 75 f4 c3 00 00 00  |........<.u.....|
000001b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 24 12  |..............$.|
000001c0  0f 09 00 be bd 7d 31 c0  cd 13 46 8a 0c 80 f9 00  |.....}1...F.....|
000001d0  75 0f be da 7d e8 cf ff  eb 9d 46 6c 6f 70 70 79  |u...}.....Floppy|
000001e0  00 bb 00 70 b8 01 02 b5  00 b6 00 cd 13 72 d7 b6  |...p.........r..|
000001f0  01 b5 4f e9 e6 fe 00 00  00 00 00 00 00 00 55 aa  |..O...........U.|
＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊
[root@server grub]# hexdump -C mbr.img | tail -10
00000170  06 be 94 7d e8 30 00 be  99 7d e8 2a 00 eb fe 47  |...}.0...}.*...G|
00000180  52 55 42 20 00 47 65 6f  6d 00 48 61 72 64 20 44  |RUB .Geom.Hard D|
00000190  69 73 6b 00 52 65 61 64  00 20 45 72 72 6f 72 00  |isk.Read. Error.|
000001a0  bb 01 00 b4 0e cd 10 ac  3c 00 75 f4 c3 00 00 00  |........<.u.....|
000001b0  00 00 00 00 00 00 00 00  01 c0 01 c0 00 00 80 01  |................|
000001c0  01 00 07 fe ff ff 3f 00  00 00 a7 14 00 05 00 00  |......?.........|
000001d0  c1 ff 07 fe ff ff e6 14  00 05 e6 14 00 05 00 fe  |................|
000001e0  ff ff 83 fe ff ff cc 29  00 0a 53 a8 04 00 00 fe  |.......)..S.....|
000001f0  ff ff 05 fe ff ff 1f d2  04 0a a2 b8 9c 08 55 aa  |..............U.|

abaity

MBR后66个字节是分区表（占64个字节）和标示符（magic number）。mbr只复制stage1中的前446个字节。