[ltp] Re: Bios Splash

Paul Bolle linux-thinkpad@linux-thinkpad.org
Tue, 07 Feb 2012 11:54:34 +0100

On Tue, 2012-02-07 at 09:55 +0100, Adam Furmanczuk wrote:
> i will try this week and keep you updated on maillinglist and (when
> successfull) on wiki.

0) Have fun.

1) An easy way to determine the offset of the El Torito boot image
turned out to be:
    $ isoinfo -d -i 8nuj08uc.iso | grep -e "block size" -e Bootoff
    Logical block size is: 2048
            Bootoff 1B 27

So that offset is (27 * 2048 =) 0xD800.

2) I miscalculated the size of that boot image. It's a 17825792 bytes
(34816 sectors of 512 bytes) hard disk image. Note that the size of the
image is not really relevant for loop mounting it, since its offset into
the ISO image (0xD800 + 32 * 512 = 71680) is enough to do that.

Paul Bolle