NetBSD-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Removing bootstrap data on i386

On Tue, Dec 15, 2009 at 10:23:50PM +0100, Ingolf Steinbach wrote:
> Thank you for the hint. Unfortunately my BIOS still detects that there
> is boot code on that disk and run it which then leads to errors as
> there is no active partition.
> Isn't there any possibility to actually remove the boot code?

  Here's something which might work for you, but I'm not certain it
won't cause data loss (and I strongly suspect there's a more proper
way to handle this, but I don't remember).  Anyway: try it at your
own risk:

 o  copy sector 0 of the drive into a file
    (e.g.: "dd if=/dev/rwd0d of=my_mbr count=1")

 o  zero the first 4 bytes of this file
    (emacs can edit binaries, and there are various other methods)

 o  write the file back to the drive
    (e.g.: "dd if=my_mbr of=/dev/rwd0d count=1")

This won't actually REMOVE all the boot code, but my hope is that
the zero-bytes may render it unrecognizable to the BIOS (which 
sounds like it's close enough to what you're asking for).  Perhaps
others will comment with a more rigorous explanation--or maybe a
better method entirely.

Cheers,  --Dave B.
Boston, MA

Home | Main Index | Thread Index | Old Index