On 10/21/07, William Case <billlinux@xxxxxxxxxx> wrote: > Hi; > > As a result of the ongoing GRUB discussion, I have been trying to trace > the use of GRUB from BIOS to the end of GRUB stage 2. I am particularly > interested in seeing how the MBR is used. > > I can create a temporary copy of my MBR using: > # dd if=/dev/sdX of=/tmp/sda-mbr.bin bs=512 count=1 > > My question is; what program should I use to read this file in a human > meaningful way (hexdump??)? I am trying to see how the MBR names > partitions; and how GRUB uses those names. That is, are the partitions > named in MBR actually named hd0,0 (ie the binary or hex equivalent of > hd0,0) etc. or is there a further translation step required by GRUB? > Does the device/partitioning system used by MBR and GRUB have a name(s)? > (For Internet search purposes). > > I am interested in the hardware/software interface of booting. Is there > anything additional I should know about this partition-locating process? > > -- > Regards Bill > > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list > I simply pipe dd to xxd. dd {......} | xxd And as Robert indicated, the 512 bytes is broken down as MBR for 446 bytes, 64 bytes for partition table (4 X 15), and 2 byte magic number \x55\xaa. I spent a bit of time last Spring trying to figure out where in the MBR code was the info telling it where to get stage 1.5. I didn't spend any real significant time on it seeing it was way beyond what I had to understand so dropped it due to lack of time. If you figure out that info I'd be interested. Jacques B.
