The script below contains the fixes mentioned in the thread so far.
It only generates menu entries using the one xen.gz hypervisor to eliminate the geometric entry number problem. The most recently installed hypervisor overwrites this symlink with one pointing to itself. The result is that you will only have entries for one hypervisor * the number of dom0 capable kernels.
I made one more change such that if GRUB_CMDLINE_XEN_DEFAULT is not in /etc/default/grub, then it will ignore xen completely and not generate any additional boot entries. This should make it undetectable by anyone not explicitly wanting Xen boot entries.
#!/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`
grub -q GRUB_CMDLINE_XEN_DEFAULT || list=""
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 /boot/xen.gz dummy=dummy $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