On Mar 6, Gordon Matzigkeit wrote:
> >>>>> Gabor Liptak writes:
>
> GL> Let me repeat again what I'm trying to do here. I would like to
> GL> be able to use dd to save an image from a bootable floppy disk to
> GL> my hard drive and use grub to boot that image as a "bootable"
> GL> file. Is this doable?
>
> Grub can certainly load the first sector of your image at 0:7c00, and
> transfer control to it, but you have to ask yourself ``how is the
> loaded sector supposed to find the rest of the image in order to
> continue the bootstrap?''
>
> The problem is not in Grub, the problem is that there is no standard
> way of communicating the location of the image to the image's
> bootstrap code. If you think of a way, then you should propose it,
> and then maybe it will one day be supported by Grub.
This could be done with a similar mechanism as the "map" command:
Install an int-13 handler that maps a disk image to a bios drive. It
is much more difficult though: The handler has to transform the CHS
(cylinder/head/address) triple into a linear block number, add the
address of the first block of the disk file and recalculate this
address to a new CHS address. If the file is fragmentated it is even
more difficult. And if the OS circumvents the bios (like linux does)
one must use a technique like initrd anyway.
Jochen
