[Nottingham] Boot sector and MBR

[peter.chang at nottingham.ac.uk]

Someone was asking about the difference between GRUB and LILO.
Well, check out
 http://www.geocities.com/thestarman3/asm/mbr/MBR_in_detail.htm

Watch out for MBRs that started life as LILO and got switched to GRUB
(say, by upgrading a Red Hat distribution).

For instance, dumping my MBR

# dd if=/dev/hda of=mbr.dat bs=512 count=1

# od -tx1z mbr.dat
0000000 eb 48 90 6c 62 61 4c 49 4c 4f 01 00 15 04 5a 00  
>.H.lbaLILO....Z.<

[snipped]

0000160 41 bb aa 55 cd 13 5a 52 72 49 81 fb 55 aa 75 43  
>A..U..ZRrI..U.uC<

[snipped]

0000560 7d e8 2a 00 eb fe 47 52 55 42 20 00 47 65 6f 6d  
>}.*...GRUB .Geom<
0000600 00 48 61 72 64 20 44 69 73 6b 00 52 65 61 64 00  
>.Hard Disk.Read.<
0000620 20 45 72 72 6f 72 00 bb 01 00 b4 0e cd 10 ac 3c  
> Error.........<<

which as you can see holds both ASCII signatures.

Peter