Dear GRUB-developers,
I recently had a discussion with the GRUB-maintainers in Debian if it
will be possible to add other (maybe proprietary, preinstalled) OSes to
the GRUB boot menu when update-grub is run [1]. This happens
automatically when Debian is installed (via the Debian-Installer) using
a tool called 'os-prober'. This tool mounts all possible partitions and
reports if it finds an OS on these partitions. This means it should be
possible to run 'os-prober' and interpret it's output to generate
further GRUB menu entries every time update-grub is started. For this
purpose, please find my approach for an /etc/grub.d/30_os-prober script
attached. It is only 1.5 kB, tab-indented and full of comments and
paranoid tests. If it is considered usefull, though, I'd like to hand it
over (including copyright!) to the GRUB-developers.
At the moment there is still one problem left: os-prober returns the
partition on which it finds the OS as a system device name, e.g.
/dev/hda2. At the moment, GRUB does not provide an (easy) way to
translate these into GRUB drives, e.g. (hd0,1). This is why I allready
requested such a feature on this list [2].
Another problem (or: missing feature) is, that at the moment my script
can only add chainloaded OSes to grub.cfg. To add kernels like Linux or
HURD it is necessary to mount these partitions again to find out exactly
where the kernel and initrd images reside. This is something I want to
avoid, because the partitions have allready been mounted by os-prober
and I don't want to duplicate it's code for this purpose. Maybe
os-prober could be modified to be more verbose in such cases and report
the entire path to the images.
You may consider this a very Debian specific problem/feature, but I
believe once os-prober finds more attention by other Linux distributions
it will provide a very valuable means to automatically detect other OSes
and add them to the boot menu.
Cheers,
Fabian
[1] http://bugs.debian.org/461442
[2] http://lists.gnu.org/archive/html/grub-devel/2008-01/msg00446.html
http://bugs.debian.org/462218
--
Dipl.-Phys. Fabian Greffrath
Ruhr-Universität Bochum
Lehrstuhl für Energieanlagen und Energieprozesstechnik (LEAT)
Universitätsstr. 150, IB 3/134
D-44780 Bochum
Telefon: +49 (0)234 / 32-26334
Fax: +49 (0)234 / 32-14227
E-Mail: [EMAIL PROTECTED]
#! /bin/sh -e
# update-grub helper script.
# <insert copyright and license blurb here>
if [ -x "`which os-prober 2>/dev/null`" ] ; then
# os-prober output contains the partition and the name, a label and
# a boot keyword, separated by colons (:) for each detected OS.
# It may contain space characters and linebreaks,
# e.g. "/dev/hda2:Windows XP Professional:Windows:chain".
# Convert space characters to underscores and linebreaks to spaces.
RESULT="`os-prober | tr ' ' '_' | tr '\n' ' '`"
fi
if [ "x${RESULT}" != "x" ] ; then
for OS in "${RESULT}" ; do
# e.g. "/dev/hda2:Windows_XP_Professional:Windows:chain"
PARTITION="`echo ${OS} | cut -d ':' -f 1`"
LONGNAME="`echo ${OS} | cut -d ':' -f 2 | tr '_' ' '`"
LABEL="`echo ${OS} | cut -d ':' -f 3`"
BOOT="`echo ${OS} | cut -d ':' -f 4`"
if [ "x${LONGNAME}" = "x" ] ; then
# is this likely to happen?
LONGNAME="${LABEL}"
fi
case "${BOOT}" in
chain)
echo "Found ${LONGNAME} on ${PARTITION}" >&2
if [ -x "`which grub-probe 2>/dev/null`" ] ;
then
# need to convert partition device to
GRUB drive here!
GRUB_DEVICE="`grub-probe --something
${PARTITION}`"
cat << EOF
menuentry "${LONGNAME} (on ${PARTITION})" {
set root=${GRUB_DEVICE}
chainloader +1
}
EOF
else # wtf?!
echo " Error: Missing grub-probe!" >&2
fi
;;
macos|macosx)
# can't macos* also be chainloaded?
;;
hurd|linux)
# other Linux/HURD-Systems are not (yet)
supported
# with the given output of os-prober
;;
*)
# is it possible to reach here?
;;
esac
done
fi
