#!/bin/bash
# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
# Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>
#
# Released under the terms of the GNU GPL
#
# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
# the cpio archive, and gzip to pack it.
# The script may also be used to generate the inputfile used for gen_init_cpio
# This script assumes that gen_init_cpio is located in usr/ directory

# error out on errors
set -e

usage() {
cat << EOF
Usage:
$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
	-o <file>      Create gzipped initramfs file named <file> using
		       gen_init_cpio and gzip
	-u <uid>       User ID to map to user ID 0 (root).
		       <uid> is only meaningful if <cpio_source>
		       is a directory.
	-g <gid>       Group ID to map to group ID 0 (root).
		       <gid> is only meaningful if <cpio_source>
		       is a directory.
	<cpio_source>  File list or directory for cpio archive.
		       If <cpio_source> is a .cpio file it will be used
		       as direct input to initramfs.
	-d             Output the default cpio list.

All options except -o and -l may be repeated and are interpreted
sequentially and immediately.  -u and -g states are preserved across
<cpio_source> options so an explicit "-u 0 -g 0" is required
to reset the root/group mapping.
EOF
}