#! /bin/sh -e

if [ -f /usr/share/grub/grub-mkconfig_lib ]; then
    . /usr/share/grub/grub-mkconfig_lib
else
  # no grub file, so we notify and exit gracefully
    echo "Cannot find grub config file, exiting." >&2
    exit 0
fi

XEN_HYPERVISOR_CMDLINE="xsave=1"
XEN_LINUX_CMDLINE="console=tty0"
[ -r /etc/xen/grub.conf ] && . /etc/xen/grub.conf

CLASS="--class gnu-linux --class gnu --class os"

if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
    OS=GNU/Linux
else
  if [ "${GRUB_DISTRIBUTOR}" = "Parabola" ] ; then
      OS="${GRUB_DISTRIBUTOR} GNU/Linux-libre"
  elif [ "${GRUB_DISTRIBUTOR}" = "parabola" ] ; then
      OS="${GRUB_DISTRIBUTOR} GNU/Linux-libre"
  else
      OS="${GRUB_DISTRIBUTOR} GNU/Linux"
  fi
    CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr '[A-Z]' '[a-z]' | cut -d' ' -f1) ${CLASS}"
fi

# 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}" \
    || [ "`grub-probe -t abstraction --device ${GRUB_DEVICE} | sed -e 's,.*\(lvm\).*,\1,'`" = "lvm"  ] ; then
    LINUX_ROOT_DEVICE=${GRUB_DEVICE}
else
    LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
fi

xen_entry ()
{
    os="$1"
    xen_version="$2"
    version="$3"
    xen_args="$4"
    args="$5"
    printf "menuentry 'Xen %s / %s, with Linux %s' --class xen ${CLASS} {\n" "${xen_version}" "${os}" "${version}"
    save_default_entry | sed -e "s/^/\t/"

    if [ -z "${prepare_boot_cache}" ]; then
        prepare_boot_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/")"
    fi
    printf '%s\n' "${prepare_boot_cache}"
    cat << EOF
       echo    '$(printf "Loading Xen %s ..." ${xen_version})'
       multiboot       ${rel_dirname}/${xen_basename} ${rel_dirname}/${xen_basename} ${xen_args}
       echo    $(printf "$(gettext "Loading Linux %s ...")" ${version})
       module  ${rel_dirname}/${basename} ${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro ${args}
EOF
    if test -n "${initrd}" ; then
        cat << EOF
       echo    "Loading initial ramdisk ..."
       module  ${rel_dirname}/${initrd}
EOF
    fi
    cat << EOF
}
EOF
}

xen_list=`for i in /boot/xen-*.gz /xen-*.gz ; do
       if grub_file_is_not_garbage "$i" ; then echo -n "$i "; fi
done`
prepare_boot_cache=

while [ "x$xen_list" != "x" ] ; do
    xen=`version_find_latest $xen_list`
    echo "Found Xen hypervisor image: $xen" >&2
    xen_basename=`basename $xen`
    xen_dirname=`dirname $xen`
    rel_xen_dirname=`make_system_path_relative_to_its_root $xen_dirname`
    xen_version=`echo $xen_basename | sed -e "s,^[^0-9]*-,,g" | sed -e "s,.gz,,g"`
    alt_xen_version=`echo $xen_version | sed -e "s,\.old$,,g"`

    list="/boot/vmlinuz-linux";

    while [ "x$list" != "x" ] ; do
        linux=`version_find_latest $list`
        echo -e "\tFound 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"`
        base_init=`echo $basename | sed -e "s,vmlinuz,initramfs,g"`
        alt_version="${base_init}-fallback"
        linux_root_device_thisversion="${LINUX_ROOT_DEVICE}"
        initrd=

        for i in "${base_init}.img"; do
            if test -e "${dirname}/${i}" ; then
                initrd="$i"
                break
            fi
        done
        if test -n "${initrd}" ; then
            echo -e "\tFound 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

        xen_entry "${OS}" "${xen_version}" "${version}" \
            "${XEN_HYPERVISOR_CMDLINE}" \
            "${XEN_LINUX_CMDLINE}"

        list=`echo $list | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '`
    done

    xen_list=`echo $xen_list | tr ' ' '\n' | grep -vx $xen | tr '\n' ' '`
done