kexec-bootloader

#! /usr/bin/sh

# Print help text and exit.
#
usage () {
  cat <<EOF
Usage: kexec-bootloader [OPTIONS]
Loads kexec kernel from bootloader configuration.

Options:

    -D, --debug         Print debugging information.
        --dry-run       Do everything but don't actually run kexec.
    -h, --help          Show this help message.

kexec-bootloader gets the default kernel, initrd, and boot options and
prepares a kexec() system call with it.

You then can run 'kexec --exec' to boot with this configuration.
EOF

  exit "$1"
}

while true ; do
  case $1 in
    -D|--debug) opt_debug=1 ; shift ; continue ;;
       --dry-run) opt_dry_run=1; shift ; continue ;;
    -h|--help) usage 0 ;;
  esac

  break
done

[ "$#" != 0 ] && usage 1

. <(pbl --default-settings) || {
  echo "pbl failed to provide settings" >&2
  exit 1
}

for i in $(cat /proc/cmdline) ; do
  case $i in
    root=*) root=$i ; break ;;
  esac
done

if [ -z "$root" ] ; then
  echo "Could not determine no 'root' option." >&2
  exit 1
fi

kexec="kexec --kexec-syscall-auto --load '$kernel' --initrd='$initrd' --append='$root $append'"

if [ "$opt_debug" = 1 ] ; then
  echo "Image  : $kernel"
  echo "Initrd : $initrd"
  echo "Append : $append"
  echo "Root   : $root"
  echo "Kexec call: $kexec"
fi

if [ "$opt_dry_run" != 1 ] ; then
  sh -c "$kexec" || {
    echo "kexec failed." >&2
    exit 1
  }
fi

exit 0