#!/bin/sh

  # 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.

  # 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>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...

  	-o <file>      Create initramfs file named <file> by using gen_init_cpio

  	-l <dep_list>  Create dependency list named <dep_list>

  	-u <uid>       User ID to map to user ID 0 (root).

  		       <uid> is only meaningful if <cpio_source> is a
  		       directory.  "squash" forces all files to uid 0.

  	-g <gid>       Group ID to map to group ID 0 (root).

  		       <gid> is only meaningful if <cpio_source> is a
  		       directory.  "squash" forces all files to gid 0.

  	<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.

  
  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
  }

  # awk style field access
  # $1 - field number; rest is argument string
  field() {
  	shift $1 ; echo $1
  }

  filetype() {
  	local argv1="$1"
  
  	# symlink test must come before file test
  	if [ -L "${argv1}" ]; then
  		echo "slink"
  	elif [ -f "${argv1}" ]; then
  		echo "file"
  	elif [ -d "${argv1}" ]; then
  		echo "dir"
  	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
  		echo "nod"
  	elif [ -p "${argv1}" ]; then
  		echo "pipe"
  	elif [ -S "${argv1}" ]; then
  		echo "sock"
  	else
  		echo "invalid"
  	fi
  	return 0
  }
  
  print_mtime() {

  	local my_mtime="0"

  	if [ -e "$1" ]; then
  		my_mtime=$(find "$1" -printf "%T@
  " | sort -r | head -n 1)

  	fi

  	echo "# Last modified: ${my_mtime}" >> $cpio_list
  	echo "" >> $cpio_list

  }
  
  list_parse() {

  	if [ -z "$dep_list" -o -L "$1" ]; then

  		return
  	fi

  	echo "$1" | sed 's/:/\\:/g; s/$/ \\/' >> $dep_list

  }

  # for each file print a line in following format
  # <filetype> <name> <path to file> <octal mode> <uid> <gid>
  # for links, devices etc the format differs. See gen_init_cpio for details

  parse() {
  	local location="$1"

  	local name="/${location#${srcdir}}"

  	# change '//' into '/'

  	name=$(echo "$name" | sed -e 's://*:/:g')

  	local mode="$2"
  	local uid="$3"
  	local gid="$4"
  	local ftype=$(filetype "${location}")
  	# remap uid/gid to 0 if necessary

  	[ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
  	[ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0

  	local str="${mode} ${uid} ${gid}"

  	[ "${ftype}" = "invalid" ] && return 0
  	[ "${location}" = "${srcdir}" ] && return 0

  
  	case "${ftype}" in
  		"file")
  			str="${ftype} ${name} ${location} ${str}"
  			;;
  		"nod")

  			local dev="`LC_ALL=C ls -l "${location}"`"

  			local maj=`field 5 ${dev}`
  			local min=`field 6 ${dev}`
  			maj=${maj%,}
  
  			[ -b "${location}" ] && dev="b" || dev="c"
  
  			str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"

  			;;
  		"slink")

  			local target=`readlink "${location}"`

  			str="${ftype} ${name} ${target} ${str}"
  			;;
  		*)
  			str="${ftype} ${name} ${str}"
  			;;
  	esac

  	echo "${str}" >> $cpio_list

  
  	return 0
  }

  unknown_option() {
  	printf "ERROR: unknown option \"$arg\"
  " >&2
  	printf "If the filename validly begins with '-', " >&2
  	printf "then it must be prefixed
  " >&2
  	printf "by './' so that it won't be interpreted as an option." >&2
  	printf "
  " >&2
  	usage >&2
  	exit 1
  }

  header() {

  	printf "
  #####################
  # $1
  " >> $cpio_list

  }
  
  # process one directory (incl sub-directories)
  dir_filelist() {

  	header "$1"

  
  	srcdir=$(echo "$1" | sed -e 's://*:/:g')

  	dirlist=$(find "${srcdir}" -printf "%p %m %U %G
  " | LANG=C sort)

  
  	# If $dirlist is only one line, then the directory is empty
  	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then

  		print_mtime "$1"

  
  		echo "${dirlist}" | \
  		while read x; do

  			list_parse $x
  			parse $x

  		done
  	fi

  }

  input_file() {
  	source="$1"
  	if [ -f "$1" ]; then

  		# If a regular file is specified, assume it is in
  		# gen_init_cpio format

  		header "$1"

  		print_mtime "$1" >> $cpio_list
  		cat "$1"         >> $cpio_list

  		if [ -n "$dep_list" ]; then
  		        echo "$1 \\"  >> $dep_list

  			cat "$1" | while read type dir file perm ; do

  				if [ "$type" = "file" ]; then

  					echo "$file \\" >> $dep_list

  				fi
  			done

  		fi

  	elif [ -d "$1" ]; then

  		# If a directory is specified then add all files in it to fs

  		dir_filelist "$1"

  	else

  		echo "  ${prog}: Cannot open '$1'" >&2

  		exit 1
  	fi
  }

  prog=$0

  root_uid=0
  root_gid=0

  dep_list=

  cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)

  output="/dev/stdout"

  trap "rm -f $cpio_list" EXIT

  while [ $# -gt 0 ]; do
  	arg="$1"
  	shift
  	case "$arg" in

  		"-l")	# files included in initramfs - used by kbuild
  			dep_list="$1"
  			echo "deps_initramfs := \\" > $dep_list
  			shift
  			;;

  		"-o")	# generate cpio image named $1
  			output="$1"

  			shift
  			;;

  		"-u")	# map $1 to uid=0 (root)

  			root_uid="$1"

  			[ "$root_uid" = "-1" ] && root_uid=$(id -u || echo 0)

  			shift
  			;;

  		"-g")	# map $1 to gid=0 (root)

  			root_gid="$1"

  			[ "$root_gid" = "-1" ] && root_gid=$(id -g || echo 0)

  			shift
  			;;

  		"-h")
  			usage
  			exit 0
  			;;
  		*)
  			case "$arg" in
  				"-"*)

  					unknown_option

  					;;

  				*)	# input file/dir - process it

  					input_file "$arg"

  					;;
  			esac
  			;;
  	esac
  done

  # If output_file is set we will generate cpio archive

  # we are careful to delete tmp files

  timestamp=
  if test -n "$KBUILD_BUILD_TIMESTAMP"; then
  	timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
  	if test -n "$timestamp"; then
  		timestamp="-t $timestamp"

  	fi

  fi

  usr/gen_init_cpio $timestamp $cpio_list > $output