#! /bin/sh
set -e

# grub-mkconfig helper script.
# Copyright (C) 2022 TTTech Industrial Automation AG
#
# Create boot menu entry to boot default entry with kernel parameters
# add required by acrn-board-inspector
#
# GRUB is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# GRUB is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.

. "$pkgdatadir/grub-mkconfig_lib"

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

# to be appended for acrn-board-inspector
GRUB_CMDLINE_ACRN_BOARD_INSPECTOR="iomem=relaxed intel_idle.max_cstate=0 intel_pstate=disable"

if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
  OS=GNU/Linux
else
  case ${GRUB_DISTRIBUTOR} in
    Ubuntu|Kubuntu)
      OS="${GRUB_DISTRIBUTOR}"
      ;;
    *)
      OS="${GRUB_DISTRIBUTOR} GNU/Linux"
      ;;
  esac
  CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr 'A-Z' 'a-z' | cut -d' ' -f1|LC_ALL=C sed 's,[^[:alnum:]_],_,g') ${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/"`
    # We can't cope with devices loop-mounted from files here.
    case ${GRUB_DEVICE} in
      /dev/*) ;;
      *) exit 0 ;;
    esac
  ;;
esac

# Default to disabling partition uuid support to maintian compatibility with
# older kernels.
GRUB_DISABLE_LINUX_PARTUUID=${GRUB_DISABLE_LINUX_PARTUUID-true}

# btrfs may reside on multiple devices. We cannot pass them as value of root= parameter
# and mounting btrfs requires user space scanning, so force UUID in this case.
if ( [ "x${GRUB_DEVICE_UUID}" = "x" ] && [ "x${GRUB_DEVICE_PARTUUID}" = "x" ] ) \
    || ( [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
	&& [ "x${GRUB_DISABLE_LINUX_PARTUUID}" = "xtrue" ] ) \
    || ( ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
	&& ! test -e "/dev/disk/by-partuuid/${GRUB_DEVICE_PARTUUID}" ) \
    || ( test -e "${GRUB_DEVICE}" && uses_abstraction "${GRUB_DEVICE}" lvm ); then
  LINUX_ROOT_DEVICE=${GRUB_DEVICE}
elif [ "x${GRUB_DEVICE_UUID}" = "x" ] \
    || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ]; then
  LINUX_ROOT_DEVICE=PARTUUID=${GRUB_DEVICE_PARTUUID}
else
  LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
fi

case x"$GRUB_FS" in
    xbtrfs)
	rootsubvol="`make_system_path_relative_to_its_root /`"
	rootsubvol="${rootsubvol#/}"
	if [ "x${rootsubvol}" != x ]; then
	    GRUB_CMDLINE_LINUX="rootflags=subvol=${rootsubvol} ${GRUB_CMDLINE_LINUX}"
	fi;;
    xzfs)
	rpool=`${grub_probe} --device ${GRUB_DEVICE} --target=fs_label 2>/dev/null || true`
	bootfs="`make_system_path_relative_to_its_root / | sed -e "s,@$,,"`"
	LINUX_ROOT_DEVICE="ZFS=${rpool}${bootfs%/}"
	;;
esac

if [ -x /lib/recovery-mode/recovery-menu ]; then
    GRUB_CMDLINE_LINUX_RECOVERY=recovery
else
    GRUB_CMDLINE_LINUX_RECOVERY=single
fi

linux_entry ()
{
  os="$1"
  version="$2"
  args="$3"

  if [ -z "$boot_device_id" ]; then
      boot_device_id="$(grub_get_device_id "${GRUB_DEVICE}")"
  fi
  echo "menuentry '$(echo "$os, with Linux ${version}" | grub_quote)' ${CLASS} \$menuentry_id_option 'gnulinux-acrn-board-inspector-$boot_device_id' {"

  # Use ELILO's generic "efifb" when it's known to be available.
  # FIXME: We need an interface to select vesafb in case efifb can't be used.
  if [ "x$GRUB_GFXPAYLOAD_LINUX" = x ]; then
      echo "	load_video"
  else
      if [ "x$GRUB_GFXPAYLOAD_LINUX" != xtext ]; then
	  echo "	load_video"
      fi
  fi
  if [ "x$GRUB_GFXPAYLOAD_LINUX" != x ]; then
      echo "	gfxmode \$linux_gfx_mode"
  fi

  echo "	insmod gzio"

  if [ x$dirname = x/ ]; then
    if [ -z "${prepare_root_cache}" ]; then
      prepare_root_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE} | grub_add_tab)"
    fi
    printf '%s\n' "${prepare_root_cache}"
  else
    if [ -z "${prepare_boot_cache}" ]; then
      prepare_boot_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | grub_add_tab)"
    fi
    printf '%s\n' "${prepare_boot_cache}"
  fi
  message="$(gettext_printf "Loading Linux %s ..." ${version})"
  cat << EOF
	echo	'$(echo "$message" | grub_quote)'
EOF
  if test -d /sys/firmware/efi && test -e "${linux}.efi.signed"; then
    cat << EOF
	linux	${rel_dirname}/${basename}.efi.signed root=${linux_root_device_thisversion} ro ${args}
EOF
  else
    cat << EOF
	linux	${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro ${args}
EOF
  fi
  if test -n "${initrd}" ; then
    # TRANSLATORS: ramdisk isn't identifier. Should be translated.
    message="$(gettext_printf "Loading initial ramdisk ...")"
    cat << EOF
	echo	'$(echo "$message" | grub_quote)'
EOF
    initrd_path=
    for i in ${initrd}; do
      initrd_path="${initrd_path} ${rel_dirname}/${i}"
    done
    cat << EOF
	initrd	$(echo $initrd_path)
EOF
  fi
  cat << EOF
}
EOF
}

machine=`uname -m`
case "x$machine" in
    xx86_64)
	GENKERNEL_ARCH="x86"
	list=
	for i in /boot/vmlinuz-* /vmlinuz-* /boot/kernel-* ; do
	    if grub_file_is_not_garbage "$i" ; then list="$list $i" ; fi
	done ;;
    *)
	list=
	;;
esac

prepare_boot_cache=
prepare_root_cache=
boot_device_id=

while [ "x$list" != "x" ] ; do
  linux=$(echo ${list} | tr ' ' '\n' | sed -e 's/\.old$/ 1/; / 1$/! s/$/ 2/' | LC_ALL=C sort -V -r | sed -e 's/ 1$/.old/; s/ 2$//' | head -n 1)
  case $linux in
    *.efi.signed)
      # We handle these in linux_entry.
      list=`echo $list | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '`
      continue
      ;;
  esac
  gettext_printf "Found linux image: %s\n" "$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_early=
  for i in ${GRUB_EARLY_INITRD_LINUX_STOCK} \
	   ${GRUB_EARLY_INITRD_LINUX_CUSTOM}; do
    if test -e "${dirname}/${i}" ; then
      initrd_early="${initrd_early} ${i}"
    fi
  done

  initrd_real=
  for i in "initrd.img-${version}" "initrd-${version}.img" "initrd-${version}.gz" \
	   "initrd-${version}" "initramfs-${version}.img" \
	   "initrd.img-${alt_version}" "initrd-${alt_version}.img" \
	   "initrd-${alt_version}" "initramfs-${alt_version}.img" \
	   "initramfs-genkernel-${version}" \
	   "initramfs-genkernel-${alt_version}" \
	   "initramfs-genkernel-${GENKERNEL_ARCH}-${version}" \
	   "initramfs-genkernel-${GENKERNEL_ARCH}-${alt_version}"; do
    if test -e "${dirname}/${i}" ; then
      initrd_real="${i}"
      break
    fi
  done

  initrd=
  if test -n "${initrd_early}" || test -n "${initrd_real}"; then
    initrd="${initrd_early} ${initrd_real}"

    initrd_display=
    for i in ${initrd}; do
      initrd_display="${initrd_display} ${dirname}/${i}"
    done
    gettext_printf "Found initrd image: %s\n" "$(echo $initrd_display)" >&2
  fi

  config=
  for i in "${dirname}/config-${version}" "${dirname}/config-${alt_version}" "/etc/kernels/kernel-config-${version}" ; do
    if test -e "${i}" ; then
      config="${i}"
      break
    fi
  done

  initramfs=
  if test -n "${config}" ; then
      initramfs=`grep CONFIG_INITRAMFS_SOURCE= "${config}" | cut -f2 -d= | tr -d \"`
  fi

  if test -z "${initramfs}" && test -z "${initrd_real}" ; then
    # "UUID=" and "ZFS=" magic is parsed by initrd or initramfs.  Since there's
    # no initrd or builtin initramfs, it can't work here.
    if [ "x${GRUB_DEVICE_PARTUUID}" = "x" ] \
	|| [ "x${GRUB_DISABLE_LINUX_PARTUUID}" = "xtrue" ]; then

	linux_root_device_thisversion=${GRUB_DEVICE}
    else
	linux_root_device_thisversion=PARTUUID=${GRUB_DEVICE_PARTUUID}
    fi
  fi

  linux_entry "${OS} - ACRN Board Inspector" "${version}" \
    "${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_LINUX_DEFAULT} ${GRUB_CMDLINE_ACRN_BOARD_INSPECTOR}"

  if [ -z "$boot_device_id" ]; then
    boot_device_id="$(grub_get_device_id "${GRUB_DEVICE}")"
  fi

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

echo ""
