In LiveDistro grub-mkconfig not work (cannot find a device for / (is /dev mounted?))

[smah oneandteo]

Problem:
When I try use cammand like "update-grub2" or "grub-mkconfig -o grub.cfg" in  LiveDistro, raise error :
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).
In grub 1.98.

Background:
I have OpenSuse with grub legacy.When installed windows,bootloader was damaged.So I must reinstall grub but I had LiveCD of Ubuntu 10.10 (with grub1.98).I could install grub2  bootloader but I can not generate grub.cfg from menu.lst.When I ran "update-grub2"
raise above error (and internet did not solve my problem).
I have decided that solved problem.First see update-grub2 script then read grub-mkconfig
script.I found error raise by grub_probe because target is "/" of LiveDistro.This
root not work.I used "chroot" and "mount --bind" many directories, but problem not
solve (or I could not).So we shall define root directory of main FHS (like mounted
to /mnt and define /mnt for target of grub_probe)

Solver:
I edit grub-mkconfig and add 3 options:
  -r, --rootdir           root directory [default=/]
  -b, --bootdir          boot directory [default=/boot]
  -g, --grubdir           grub directory [default= in linux {bootdir}/grub,in BSD /grub]
I tested it by Ubuntu 10.10 Live (grub 1.98).

Sincerely
SMAH1

grub-mkconfig.zip
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