#!/bin/sh -

# Before running, make sure 'vmlinuz' in this examples directory is a
# bootable Linux kernel or a symlink to one.  You can just use any
# kernel out of the /boot directory for this.
#
# eg:
# cd examples
# ln -s /boot/vmlinuz-NNN vmlinuz

# This creates a very minimal filesystem, just containing bash and a
# few command line utilities.  One of the joys of Fedora is that even
# this minimal install is still 200 MB ...

set -e

if [ $(id -u) -eq 0 ]; then
    echo "Don't run this script as root.  Read instructions in script first."
    exit 1
fi

if [ ! -e vmlinuz ]; then
    echo "Read instructions in script first."
    exit 1
fi

febootstrap -i bash -i coreutils fedora-10 ./minimal $1

# ... but let's minimize it aggressively.

echo -n "Before minimization: "; du -sh minimal
febootstrap-minimize --all --pack-executables ./minimal
echo -n "After minimization:  "; du -sh minimal

# Create the /init which is just a simple script to give users an
# interactive shell.

create_init ()
{
  cat > /init <<'__EOF__'
#!/bin/sh
echo; echo; echo
echo "Welcome to the minimal filesystem example"
echo; echo; echo
/bin/bash -i
__EOF__
  chmod +x /init
}
export -f create_init
febootstrap-run ./minimal -- bash -c create_init

# Convert the filesystem to an initrd image.

febootstrap-to-initramfs ./minimal > minimal-initrd.img

# This is needed because of crappiness with qemu.

rm -f zero
dd if=/dev/zero of=zero bs=2048 count=1

# Now run qemu to boot this minimal system.

qemu-system-$(arch) \
  -m 256 \
  -kernel vmlinuz -initrd minimal-initrd.img \
  -hda zero -boot c