#!/bin/sh

# TODO: use installer fast-path w/ T2 label

mkdir -p /mnt
mount -t tmpfs none /mnt

mkdir -p /mnt/{media,mnt,overlay,work}

live="live=live.squash `cat /proc/cmdline`"; live=${live##*live=}; live=${live%% *}
echo "Searching for media with $live image ..."

i=0
while [ $i -le 14 ]; do
  for x in /sys/block/*/device; do
    x=${x%/device}; x=${x#/sys/block/}
    [ "$x" = "*" ] && continue
    # TODO: make option to skip fixed devices
    #case "`ls -l /sys/block/$x/device`" in 
    #  */usb*|*/ieee1394) : ;;
    #  *) [ "`cat /sys/block/$x/removable`" = 1 ] || continue ;;
    #esac
    x=/dev/$x

    for x in ${x}*; do
      [ -e $x ] || continue
      fs=`disktype $x 2>/dev/null |
          sed -e '/file system/!d' -e 's/file system.*//' -e 's/ //g' \
              -e 'y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/' \
              -e 's/fat.*/vfat/' | sed -n '1p'` # TODO: for fs  in `| sed '1!G; $p; h; d`
      [ $i -gt 2 ] && echo "Testing device $x, type $fs ..."
      if mount -t $fs -o ro $x /mnt/media 2>/dev/null; then
	[ $i -gt 0 ] && echo "Successfully mounted $x"
	if [ -f /mnt/media/$live ]; then
	  echo "Found the $live image on $x"

	  if losetup /dev/loop0 /mnt/media/$live &&
	     mount -t squashfs -o ro /dev/loop0 /mnt/mnt
	  then
	    kill %1 # udevd

	    # pre-load overlay module, before moving it
	    modprobe overlay 2> /dev/null

	    # re-use kernel modules and firmware
	    mkdir -p /mnt/overlay/lib
	    mv /lib/{firmware,modules} /mnt/overlay/lib

	    mount -t overlay -o lowerdir=/mnt/mnt,upperdir=/mnt/overlay,workdir=/mnt/work \
		none /mnt

	    init=${init:-/sbin/init}
	    boot $init "$@"
	  else
	    echo "Failed to loop-mount $live."
	    losetup -d /dev/loop0
	  fi
	else
	  echo "No $live image found."
	fi
	umount /media/live
      fi
    done
  done
  : $(( i++ ))
  sleep 1
done

echo "No live media found, giving up. Debug shell:"
exec /bin/sh