#!/bin/ash
# Initial script for Linux Live operating system
# Author: Tomas M <http://www.linux-live.org/>

export PATH=.:/:/usr/sbin:/usr/bin:/sbin:/bin

mount -n -t proc proc /proc
mount -n -t sysfs sysfs /sys
mount -n -o remount,rw /         # for the case we forgot rw boot option
ln -sf /proc/mounts /etc/mtab    # this allows us to use umount -a

. liblinuxlive # it requires proc to be mounted

header "starting Linux Live scripts <http://www.linux-live.org/>"

# Don't print kernel messages to konsole now.
# Syslog will reset printk settings, no need to remember it here anymore.
echo "0" >/proc/sys/kernel/printk

# Load essential drivers, like CDROM drivers, aufs/squashfs etc,
# use mdev to create /dev/ devices and setup it as a hotplug-handler
modprobe_essential_modules
mdev_start_hotplug

# /usr is compressed in initrd so it must be mounted from /usr.lzm
mount_initrd_loops

# Then load drivers for data storage and input devices
modprobe_usb_modules
modprobe_pcmcia_modules

debug_shell

# make sure ext3 partitions are not mounted using ext2 driver,
# and vfat partitions are not mounted using msdos driver
echo -e "ext3\next2\nvfat\n*" >/etc/filesystems

mkdir -p $UNION
mkdir -p $MEMORY

debug_shell

# Find livecd data directory
echolog "looking for data directory"

# First, try from= boot argument, if given
DATAFROM=$(cmdline_value from)

if [ "$DATAFROM" ]; then
   DATAFROM=$(find_in_computer $DATAFROM)
   if [ "$DATAFROM" ]; then
      mount_device $DATAFROM $LOOPMOUNT # mount again, it may be loop device
      if [ $? -eq 0 -a "$(find_modules $LOOPMOUNT/$LIVECDNAME)" != "" ]; then
         echolog "found in $DATAFROM"
         DATA=$LOOPMOUNT/$LIVECDNAME
      else
         fumount $LOOPMOUNT
	 fumount $MOUNTDIR/*
      fi
   fi
fi

if [ "$DATA" = "" ]; then
   # from= is not used or it didn't contain valid data
   DATA=$(find_in_computer $LIVECDNAME/$LIVECDSGN)
   DATA=$(dirname $DATA 2>/dev/null)
fi

if [ "$DATA" = "" ]; then fatal \
"$LIVECDNAME data not found.
You are maybe using an unsupported boot device (eg. SCSI or old PCMCIA).
Workaround: Copy the directory $LIVECDNAME from your boot device to an IDE/SATA
disk, eg. to /mnt/hda1/$LIVECDNAME or C:\\$LIVECDNAME. Then try to boot again."
fi

echolog "using $LIVECDNAME data from $DATA"

debug_shell

echolog "setting up directory for changes"
CHANGESVAL=$(cmdline_value changes)

if [ "$CHANGESVAL" ]; then
   CHANGESMNT=$(find_in_computer $CHANGESVAL)
   echolog $CHANGESMNT
fi

debug_shell

mount_device "$CHANGESMNT" $MEMORY # removes $MEMORY if CHANGESMNT is wrong

# test if the filesystem is writable so changes can be stored to it
touch $MEMORY/empty 2>/dev/null && \
rm -f $MEMORY/empty 2>/dev/null

# if changes can't be mounted or the filesystem is not writable,
# fallback to the default: tmpfs
if [ $? -ne 0 ]; then
   echolog "changes not writable, using memory only"
   fumount $MEMORY
   mkdir -p $MEMORY # mount_device might removed it

   RAMSIZE=$(cmdline_value ramsize)
   if [ "$RAMSIZE" = "" ]; then RAMSIZE="60%"; fi
   mount -t tmpfs -o "size=$RAMSIZE" tmpfs $MEMORY
   XINO=$MEMORY
   mkdir -p $CHANGES
else
   # So it is writable, we will keep the filesystem mounted.
   # Check if it supports links and chmod.
   # If not, overmount CHANGES using posixovl
   echolog "testing the filesystem for posix compatibility"
   touch $MEMORY/.empty1 && \
   ln -sf $MEMORY/.empty1 $MEMORY/.empty2 2>/dev/null && \
   chmod +x $MEMORY/.empty1 2>/dev/null  && \
   test -x $MEMORY/.empty1 && \
   chmod -x $MEMORY/.empty1 2>/dev/null  && \
   test ! -x $MEMORY/.empty1 && \
   rm $MEMORY/.empty1 $MEMORY/.empty2 2>/dev/null

   if [ $? -ne 0 ]; then
      echolog "not compatible - starting posixovl"
      rm $MEMORY/.empty1 $MEMORY/.empty2 2>/dev/null
      mkdir -p $CHANGES
      posixovl -F $CHANGES
   fi
fi

# $UNION will be used as a root directory, livecd modules will be added soon
echolog "setup union directory (using aufs, with udba=none)"

debug_shell

mkdir -p $IMAGES

# store the xino file in memory in all cases, it's faster and safer
if [ "$XINO" != "$MEMORY" ]; then
   mkdir -p $XINO
   mount -n -t tmpfs tmpfs $XINO
fi

# mount aufs using the writable branch as the first one (leftmost/topmost)
mount -t aufs -o nowarn_perm,udba=none,xino=$XINO/.aufs.xino,br:$CHANGES=rw aufs $UNION
if [ $? -ne 0 ]; then fatal "can't setup union (aufs)"; fi

debug_shell

# If toram or copy2ram boot parameter is present, copy all fs modules to RAM.
# (skip modules from /optional/ which are not listed in load= boot option)
# Finaly modify DATA variable so it will point to correct directory
if [ "$(cmdline_parameter toram)" != "" -o "$(cmdline_parameter copy2ram)" != "" ]; then
   echolog "copying data to RAM, this may take some time..."
   mkdir -p $COPY2RAM

   # make sure it's in RAM even with changes= parameter
   if [ "$CHANGESMNT" ]; then mount -t tmpfs -o "size=$RAMSIZE" tmpfs $COPY2RAM; fi
   copy_to_ram $DATA $COPY2RAM

   cd_autoeject 1
   fumount $DATA
   fumount $MOUNTDIR/*
   rmdir $MOUNTDIR/* 2>/dev/null # mounted device names are empty, remove them
   DATA=$COPY2RAM
   cd_autoeject 0
fi

debug_shell

# DATA contains path to the base directory of all fs modules which need
# to be mounted and inserted into live filesystem. Do it now.
echolog "inserting all modules and creating live filesystem"
union_insert_modules $UNION $DATA $IMAGES

# the $MEMORY directory can contain $MEMORY/modules too
# in the case if changes= boot argument is used. If not, it doesn't hurt
union_insert_modules $UNION $MEMORY $IMAGES

debug_shell

echolog "copying content of rootcopy directory"
cp -af $DATA/rootcopy/* $UNION 2>/dev/null # may be empty
echolog "copying liblinuxlive library to union"
cp -af /liblinuxlive $UNION/usr/lib/

debug_shell

echolog "creating /etc/fstab"
echo -ne > $UNION/etc/fstab
fstab_update $UNION

# everything is ready now, so we may unload unused kernel modules
# and do some cleanup, unmount few things which are no longer needed.
rmmod_unused_modules
fumount /usr
fumount /sys

# More likely these directories aren't there.
# Even if they are, this won't hurt.
mkdir -p $UNION/boot
mkdir -p $UNION/proc
mkdir -p $UNION/sys
mkdir -p $UNION/dev
mkdir -p $UNION/tmp
chmod 0777 $UNION/tmp

# Boot will contain whatever was in ./boot directory in the bootable media
# Error output goes to null, as nothing is mounted with copy2ram
mount -n -o rbind $(dirname $DATA)/boot $UNION/boot 2>/dev/null

debug_shell

# Union contains all the files and directories unioned from all modules.
# Change root directory to it, and move initrd's root to /mnt/live/initramdisk
# Finaly execute /sbin/init to start the distribution.
echolog "changing root directory..."

cd $UNION
mkdir -p $INITRAMDISK

# Copy all dev files (found by mdev) to unioned dev directory
# so at least disk devices exist (your Linux may need them)
if [ ! -e /dev/console ]; then mknod /dev/console c 5 1; fi
cp -fdR /dev .

# find chroot and init
if [ -x bin/chroot ]; then  CHROOT=/bin/chroot; fi
if [ -x sbin/chroot ]; then  CHROOT=/sbin/chroot; fi
if [ -x usr/bin/chroot ]; then  CHROOT=/usr/bin/chroot; fi
if [ -x usr/sbin/chroot ]; then CHROOT=/usr/sbin/chroot; fi
if [ "$CHROOT" = "" ]; then fatal "Can't find executable chroot command"; fi

if [ -x bin/init ]; then INIT=bin/init; fi
if [ -x sbin/init ]; then INIT=sbin/init; fi
if [ "$INIT" = "" ]; then fatal "Can't find executable init command"; fi

# time to end Linux Live scripts and start the distribution itself,
# using /sbin/init or whatever was found.
header "linux live end, starting the Linux distribution"
mount -n -o remount,ro aufs .

# We will copy init from the distro to initrd (there should be 2MB free)
# This allows us to use the cleanup script during reboot, as init will be
# started from memory and not from the union and /union will not be busy.

cp -af $INIT /bin
if [ $? -eq 0 ]; then
   pivot_root . $INITRAMDISK
   exec $CHROOT . $INITRAMDISK/bin/init <dev/console >dev/console 2>&1
else # If copying fails, start init directly.
   pivot_root . $INITRAMDISK
   exec $CHROOT . $INIT <dev/console >dev/console 2>&1
fi

header "!!ERROR!!"
fatal "You are not supposed to be here, something went wrong!"

cp -af $INIT /bin
if [ $? -eq 0 ]; then
   pivot_root . $INITRAMDISK
   exec $CHROOT . $INITRAMDISK/bin/init <dev/console >dev/console 2>&1
else # If copying fails, start init directly.
   pivot_root . $INITRAMDISK
   exec $CHROOT . $INIT <dev/console >dev/console 2>&1
fi