#!/bin/bash
# Filename:      grml2ram
# Purpose:       copy compressed GRML image to RAM
# Authors:       (c) Michael Schierl <schierlm-public@gmx.de>, (c) Michael Prokop <mika@grml.org>
# Bug-Reports:   see http://grml.org/bugs/
# License:       This file is licensed under the GPL v2.
################################################################################

set -e

# shellcheck disable=SC1091
. /etc/grml/lsb-functions
# shellcheck disable=SC1091
. /etc/grml/script-functions

check4root || exit 1
check4progs rsync gawk || exit 2

if ! isgrmlcd ; then
   eerror "Not running grml in live-cd mode. Nothing to be done, exiting." ; eend 1
   exit 1
fi

# initramfs layout since December 2012, backwards compatibility:
[ -d /lib/live/mount/medium ] && export LIVECD_PATH='/lib/live/mount/medium'
# initramfs layout since December 2018:
[ -d /run/live/medium ] && export LIVECD_PATH='/run/live/medium'

if [ -z "$CMDLINE" ]; then
  # if CMDLINE was set from the outside, we're debugging.
  # otherwise, take CMDLINE from Kernel and config files.
  CMDLINE="$(cat /proc/cmdline)"
  [ -d ${LIVECD_PATH}/bootparams/ ] && CMDLINE="$CMDLINE $(cat ${LIVECD_PATH}/bootparams/* | tr '\n' ' ')"
fi

getbootparam(){
  local line
  local ws
  ws='	 '
  line=" $CMDLINE "
  case "$line" in
    *[${ws}]"$1="*)
      result="${line##*[$ws]$1=}"
      result="${result%%[$ws]*}"
      echo "$result"
      return 0 ;;
    *) # no match?
      return 1 ;;
  esac
}

MEDIA_PATH="$(getbootparam live-media-path)"
MEDIA_PATH="${MEDIA_PATH:-.}"

IMAGE=$(find "${LIVECD_PATH}/${MEDIA_PATH}/" -name "*.squashfs" 2>/dev/null | head -1)
if ! [ -r "$IMAGE" ] ; then
   if [ -r /cdrom/GRML/GRML ] ; then
      IMAGE='/cdrom/GRML/GRML'
   else
      eerror "Can not access grml squashfs file."
      eerror "Looks like you did run grml2ram already?" ; eend 1
      exit 1
   fi
fi

GRMLSIZE="$(du $IMAGE | awk '{print $1}')"
RAM=$(/usr/bin/gawk '/MemFree/{print $2}' /proc/meminfo)
LOOPDEV=$(/sbin/losetup -j "${IMAGE}" -n -O NAME)

case "$*" in -f|--force)
  ewarn "Forcing copy process for grml-image (${GRMLSIZE}kB) as requested via force option." ; eend 0
   ;;
  *)
   if test "$RAM" -lt "$GRMLSIZE" ; then
      eerror "Sorry, not enough free RAM (${RAM}kB) available for grml-image (${GRMLSIZE}kB)." ; eend 1
      exit 1
   fi
   ;;
esac

einfo "Copying $IMAGE to RAM, this might take a while."
rsync -a --progress $IMAGE /tmp/GRML
LANGUAGE=C LANG=C LC_ALL=C perl << EOF
open LOOP, '<${LOOPDEV}' or die $!;
open DEST, '</tmp/GRML' or die $!;
ioctl(LOOP, 0x4C06, fileno(DEST)) or die $!;
close LOOP;
close DEST;
EOF

# identify cd-rom:
GRMLDEV=$(awk '{if ($2 ~ /^\/lib\/live\/mount\/medium$/ ) print $1}' /etc/mtab)
if [ -z "$GRMLDEV" ]; then
  GRMLDEV=$(awk '{if ($2 ~ /^\/live\/image$/ ) print $1}' /etc/mtab)
fi
if [ -z "$GRMLDEV" ]; then
   GRMLDEV=$(awk '{if ($2 ~ /^\/cdrom$/ ) print $1}' /etc/mtab)
fi
[ -n "$GRMLDEV" ] || GRMLDEV='/dev/cdrom'

einfo "Unmounting cdrom"
if [ -d $LIVECD_PATH ] ;
then
  umount $LIVECD_PATH
else
  umount /cdrom
fi
eend $?
einfo "Now you can eject your grml-cd (e.g. run 'eject $GRMLDEV')." ; eend 0

## END OF FILE #################################################################