Apologies in advance if this is already in the works.
I wanted to provide an etc/grub.d rule for generating boot stanzas for Xen based systems such that it would end up in the upstream grub release.
It's basically a copy of etc/grub.d/10_linux and adds checks for dom0 capable kernels. I picked "09_" as I assumed that one would want to default to the Xen boot entry, but that may be a matter of some debate.
#!/bin/bash -e
#===============================================================================
#
# FILE: 09_xen
#
# USAGE: update-grub ... with this in /etc/grub.d
#
# DESCRIPTION: Generate grub2 boot stanza for Xen systems
# Xen boot entries are automatically added to grub.cfg
# The 09-... name prefix puts the Xen boot entries before
# the linux kernel entries
#
# OPTIONS: ---
# REQUIREMENTS: --- grub2, Xen hypervisor
# BUGS: --- probably
# NOTES: --- Copied from 10_linux with a few hacks to make ir work for Xen.
# Incorporated suggestions to only do this for valid dom0 kernels
# COMPANY: LSI
# VERSION: 1.0
# CREATED: 05/19/2010 02:32:34 PM PDT
# REVISION: ---
#===============================================================================
prefix=/usr
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
. ${libdir}/grub/update-grub_lib
if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
OS=GNU/Linux
else
OS="${GRUB_DISTRIBUTOR}"
fi
# Source grub defaults
. /etc/default/grub
# loop-AES arranges things so that /dev/loop/X can be our root device, but
# the initrds that Linux uses don't like that.
case ${GRUB_DEVICE} in
/dev/loop/*|/dev/loop[0-9])
GRUB_DEVICE=`losetup ${GRUB_DEVICE} | sed -e "s/^[^(]*(\([^)]\+\)).*/\1/"`
;;
esac
if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
|| ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" ; then
LINUX_ROOT_DEVICE=${GRUB_DEVICE}
else
LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
fi
test_gt ()
{
local a=`echo $1 | sed -e "s,.*/vmlinu[zx]-,,g;s/[._-]\(pre\|rc\|test\|git\|old\)/~\1/g"`
local b=`echo $2 | sed -e "s,.*/vmlinu[zx]-,,g;s/[._-]\(pre\|rc\|test\|git\|old\)/~\1/g"`
if [ "x$b" = "x" ] ; then
return 0
fi
dpkg --compare-versions "$a" gt "$b"
return $?
}
find_latest ()
{
local a=""
for i in $@ ; do
if test_gt "$i" "$a" ; then
a="$i"
fi
done
echo "$a"
}
list=`for i in /boot/vmlinu[xz]-* /vmlinu[xz]-* ; do
if grub_file_is_not_garbage "$i" && grep -q 'DOM0=y' ${i/vmlinu[xz]/config} ; then echo -n "$i " ; fi
done`
while [ "x$list" != "x" ] ; do
linux=`find_latest $list`
echo "Found linux image: $linux" >&2
basename=`basename $linux`
dirname=`dirname $linux`
rel_dirname=`make_system_path_relative_to_its_root $dirname`
version=`echo $basename | sed -e "s,^[^0-9]*-,,g"`
alt_version=`echo $version | sed -e "s,\.old$,,g"`
linux_root_device_thisversion="${LINUX_ROOT_DEVICE}"
initrd=
for i in "initrd.img-${version}" "initrd-${version}.img" \
"initrd.img-${alt_version}" "initrd-${alt_version}.img"; do
if test -e "${dirname}/${i}" ; then
initrd="$i"
break
fi
done
if test -n "${initrd}" ; then
echo "Found initrd image: ${dirname}/${initrd}" >&2
else
# "UUID=" magic is parsed by initrds. Since there's no initrd, it can't work here.
linux_root_device_thisversion=${GRUB_DEVICE}
fi
cat << EOF
insmod lvm
set root=(system-dom0_0)
menuentry "Xen ${OS}, linux ${version}" {
multiboot dummy=dummy /boot/xen.gz $GRUB_CMDLINE_XEN_DEFAULT
module ${rel_dirname}/${basename} root=${linux_root_device_thisversion} $GRUB_CMDLINE_LINUX_DEFAULT
EOF
if test -n "${initrd}" ; then
cat << EOF
module ${rel_dirname}/${initrd} ${rel_dirname}/${initrd}
EOF
fi
cat << EOF
}
EOF
list=`echo $list | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '`
done