#!/bin/sh

TARGET=$1
LANG=C

cat << EOF > ${TARGET}/message
** WMI Rescue Linux (amd64) booting **
EOF

for cmd in cat echo find insmod mkdir mount sh switch_root tar; do
    ln -s busybox ${TARGET}/bin/${cmd}
done

cat << EOF > ${TARGET}/init
#!/bin/sh
# WMI Rescue Linux init script.
# (C)2011 Michał Siejak <masterm@wmi.amu.edu.pl>
# (C)2012-2017 Mateusz Hromada <ruanda@wmi.amu.edu.pl>

# Print message banner
cat /message

# Mount virtual filesystems
mount -t proc proc /proc
mount -t sysfs sysfs /sys
mount -t devtmpfs devfs /dev

# Create dev directories
mkdir -p /dev/pts
mkdir -p /dev/shm

# Create mount points
mkdir /rootfs
mkdir /mnt
mkdir /mnt/squashfs
mkdir /mnt/tmpfs

# Load modules
insmod /lib/modules/4.9.0-3-amd64/kernel/drivers/block/loop.ko
insmod /lib/modules/4.9.0-3-amd64/kernel/fs/squashfs/squashfs.ko
insmod /lib/modules/4.9.0-3-amd64/kernel/fs/overlayfs/overlay.ko

# Mount root filesystem
echo "INITRAMFS: Mounting overlayfs branches ..."
mount -t squashfs -o loop,ro /rootfs.squash /mnt/squashfs
mount -t tmpfs -o mode=755,rw tmpfs /mnt/tmpfs
mkdir /mnt/tmpfs/rw
mkdir /mnt/tmpfs/work
mount -t overlay -o rw,workdir=/mnt/tmpfs/work,upperdir=/mnt/tmpfs/rw,lowerdir=/mnt/squashfs overlay /rootfs

# Extract any addon packages
if [ -n "\$(find . -maxdepth 1 -name '*.tar')" ]; then
  for i in /*.tar; do
    echo "INITRAMFS: Extracting: \$i ..."
    tar x -f \$i -C /rootfs
  done
fi

echo "INITRAMFS: Preparing rootfs environment ..."
# Move aufs branches to new root
mkdir -p /rootfs/media/.squashfs
mkdir -p /rootfs/media/.tmpfs
mount --move /mnt/squashfs /rootfs/media/.squashfs
mount --move /mnt/tmpfs /rootfs/media/.tmpfs

# Move virtual filesystems to new root
mount --move /proc /rootfs/proc
mount --move /sys /rootfs/sys
mount --move /dev /rootfs/dev

# Switch to new root filesystem
echo "INITRAMFS: Switching to new rootfs ..."
exec switch_root -c /dev/console /rootfs /sbin/init

# Should not reach here
echo "INITRAMFS: Could not switch to new rootfs! System halted."

exit 0
EOF
chmod a+x ${TARGET}/init