Re: Booting from USB HDD without BIOS support

From: Tauno Voipio (
Date: 06/13/05

Date: Mon, 13 Jun 2005 18:52:45 GMT

Stephan Keil wrote:
> Hi all,
> I have an external USB harddisk and installed Linux (SUSE 9.3) on it.
> Unfortunately my BIOS does not support direct booting from USB harddisks.
> I suppose it is possible to setup e.g. a small boot CD (booting from CD
> is supported), which loads a USB driver and finally boots Linux from the
> USB harddisk.
> Can anyone please give me some hints how to do this? Or does anyone have
> a better idea how to boot from the harddisk?
> Thanks and Best Regards, Stephan
> P.S.: Background: My system is a Medion MD8383XL with Phoenix 6.0 BIOS.
> The main harddisk is a SATA device, which is full of <shame> Windows XP
> </shame>.

The bootable CD contains a floppy image (usually 2.88.Mbytes)
which is shown as a floppy to the BIOS during booting.

So, you need a floppy image that contains the required drivers and
is bootable (first 512 bytes read via int 0x13 to 0x7c00 and
started up at the first byte).

For details, Google for 'El Torito Specification'.

The Linux mkisofs utility can insert the boot diskette image
into a CD file system image.

Tauno Voipio
tauno voipio (at) iki fi