#!/bin/sh
#
# redboot-cmdline
# - a tool to easily edit the kernel cmdline in fconfig
#
# Copyright (c) 2009 Canonical
# Author: Oliver Grawert <ogra@canonical.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

set -e

DEV="/dev/mmcblk0"
OFST="0x5F000"
DO_READ=""
CMDLINE=""


usage()
{
	echo "usage: $(basename $0) -r|-w \"<newcmdline>\""
	echo
	echo "	-r read existing cmdline"
	echo "	-w \"<newcmdline>\" write \"<newcmdline>\" to fis"
	echo "	-d <device> write to <device> or image"
	echo "	-o <hex offset> override <hex offset> to config data"
	echo
	exit 0
}

checkparm()
{
    if [ "$(echo $1|grep ^'\-')" ] || [ -z "$1" ];then
        echo "E: Need an argument"
        usage
    fi
}

while [ ! -z "$1" ]; do
    case $1 in
        -h|--help)
            usage
            ;;
        -d|--device)
            checkparm $2
            DEV="$2"
            ;;
        -o|--offset)
            checkparm $2
            OFST="$2"
            ;;
        -r|--read)
            DO_READ="True"
            ;;
        -w|--write)
            checkparm $2
            CMDLINE="$2"
    esac
    shift
done

if [ ! -e "${DEV}" ] || [ ! -w "${DEV}" ];then
    echo "E: cannot access $DEV (does $DEV exist ?)"
    exit 0
fi

CMD="fconfig -s -r -d ${DEV} -o ${OFST} -n boot_script_data"

if [ -n "${DO_READ}" ];then
	echo $(echo $(${CMD})|sed -e 's/^.*\"\(.*\)\".*$/\1/')
	exit 0
fi

if [ -n "${CMDLINE}" ];then
	NEWSCRIPT="$(echo "$(${CMD})"|sed s/\"[^]]*\"/\""${CMDLINE}"\"/g)\\"
	fconfig -s -w -d ${DEV} -o ${OFST} -n boot_script_data -x "${NEWSCRIPT}"
	exit 0
fi
