#! /bin/sh -e

# grub-mkconfig helper script.
# Copyright (C) 2006,2007,2008,2009,2010  Free Software Foundation, Inc.
#
# 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/>.

##############################################################################
# this is Kent Reed's attempt to create 07_rtai from 10_linux 2011/04/07
# V0.1
# 
# produces grub2 boot menu entries for rtai kernels appending "isolcpus=1" 
# after $GRUB_CMDLINE_LINUX_DEFAULT (whose value is set in /etc/default/grub)
# NOTE1: an unmodified 10_linux will later create more grub entries for the 
#        same kernels using only $GRUB_CMDLINE_LINUX_DEFAULT 
# NOTE2: deep in grub2 is a list of allowable user-defined keys so 
#        I couldn't simply define a new GRUB_CMDLINE_RTAI_DEFAULT 
#        in /etc/default/grub---SIGH!
# NOTE3: following this comment block, changes to 10_linux are preceded
#        by lines beginning #KAR: 
# NOTE4: since grub scripts aren't true shell scripts, I made no attempt
#        to break new ground. I just copied and modified existing code
# NOTE5: does it make sense to add isolcpus=1 to recovery mode?
#
# Edit by John A. Stewart 2014/08/13 - add "pae" kernel searching for 12.04
# and LinuxCNC 2.6.x
#
# Edit by Marty Vona 2014/09/20 - add quad core, nohlt, and idle=poll opts;
# don't emit "recordfail" which seems to be deprecated
##############################################################################

prefix=/usr
exec_prefix=${prefix}
bindir=${exec_prefix}/bin
libdir=${exec_prefix}/lib
. ${libdir}/grub/grub-mkconfig_lib

#KAR: define new local strings for convenience
#     if you want to change the rtai-kernel boot parameters, here's an easy
#     place to do it. 
#
#MAV: uncomment isolcpus=1 for dual core, isolcpus=1,2,3 for quad
#     these both assume hyperthreading is already disabled in bios
#
#     optionally uncomment nohlt and idle=poll lines to experiment with those
#     note: try idle=poll first as nohlt may cause increased power usage
#
RTAI_OPTS="isolcpus=1"
#RTAI_OPTS="isolcpus=1,2,3"
#RTAI_OPTS="nohlt ${RTAI_OPTS}"
#RTAI_OPTS="idle=poll ${RTAI_OPTS}"
GRUB_CMDLINE_LINUX_RTAI="${GRUB_CMDLINE_LINUX_DEFAULT} ${RTAI_OPTS}"

export TEXTDOMAIN=grub
export TEXTDOMAINDIR=@LOCALEDIR@

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

if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
  OS=GNU/Linux
else
  OS="${GRUB_DISTRIBUTOR}"
  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/"`
    # We can't cope with devices loop-mounted from files here.
    case ${GRUB_DEVICE} in
      /dev/*) ;;
      *) exit 0 ;;
    esac
  ;;
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

# add crashkernel option if we have the required tools
if [ -x "/usr/bin/makedumpfile" ] && [ -x "/sbin/kexec" ]; then
    GRUB_CMDLINE_EXTRA="$GRUB_CMDLINE_EXTRA crashkernel=384M-2G:64M,2G-:128M"
fi

linux_entry ()
{
  os="$1"
  version="$2"
  recovery="$3"
  args="$4"
  if ${recovery} ; then
    title="$(gettext_quoted "%s, with Linux %s (recovery mode)")"
  else
#KAR: augment title to make sensible grub2 boot menu entry
    title="$(gettext_quoted "%s, with Linux %s (${RTAI_OPTS})")"
  fi
  printf "menuentry '${title}' ${CLASS} {\n" "${os}" "${version}"
#  cat << EOF
#	recordfail
#EOF
  save_default_entry | sed -e "s/^/\t/"

  if [ "x$GRUB_GFXPAYLOAD_LINUX" != x ]; then
	  cat << EOF
	set gfxpayload=$GRUB_GFXPAYLOAD_LINUX
EOF
  fi

  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}"
  if [ "x$5" != "xquiet" ]; then
    cat << EOF
	echo	'$(printf "$(gettext_quoted "Loading Linux %s ...")" ${version})'
EOF
  fi
  cat << EOF
	linux	${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro ${args}
EOF
  if [ "x$5" != "xquiet" ]; then
    cat << EOF
	echo	'$(gettext_quoted "Loading initial ramdisk ...")'
EOF
  fi
  if test -n "${initrd}" ; then
    cat << EOF
	initrd	${rel_dirname}/${initrd}
EOF
  fi
  cat << EOF
}
EOF
}

blacklisted_kernel() {
  local r=""
  case "${1}" in
    *-ec2) r="linux-ec2";; # LP: #671097
  esac
  [ -n "${r}" ] && { echo "Skipping linux image [$r]: ${1}" >&2; return 0; }
  return 1;
}

#KAR: add new function to test if kernel name ends in -rtai
#JAS: add pae kernels to list.

rtai_kernel() {
  local r=""
  case "${1}" in
    *-rtai) r="true";;
    *-rtai-686-pae)r="true";;
  esac
  [ -n "${r}" ] && { return 0; }
  return 1;
}

#KAR: add rtai-kernel test in determination of suitable kernels
list=`for i in /boot/vmlinu[xz]-* /vmlinu[xz]-* ; do
        if grub_file_is_not_garbage "$i" &&
           ! blacklisted_kernel "$i" &&
           rtai_kernel "$i" ; then
          echo -n "$i ";
        fi
      done`
prepare_boot_cache=

while [ "x$list" != "x" ] ; do
  linux=`version_find_latest $list`
#KAR: modify message
  echo "Found rtai 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-${version}" "initrd.img-${alt_version}" \
	   "initrd-${alt_version}.img" "initrd-${alt_version}"; do
    if test -e "${dirname}/${i}" ; then
      initrd="$i"
      break
    fi
  done
  if test -n "${initrd}" ; then
#KAR: modify message
    echo "Found rtai 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

#KAR: change original production to use GRUB_CMDLINE_LINUX_RTAI instead of GRUB_CMDLINE_LINUX_DEFAULT
  linux_entry "${OS}" "${version}" false \
      "${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_EXTRA} ${GRUB_CMDLINE_LINUX_RTAI}" \
      quiet
  if [ "x${GRUB_DISABLE_LINUX_RECOVERY}" != "xtrue" ]; then
    linux_entry "${OS}" "${version}" true \
	"single ${GRUB_CMDLINE_LINUX}"
  fi

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