#!/bin/sh

# Create GRUB boot floppy.
#   Copyright (C) 2001 Jason Thomas <jason@debian.org>
#
# This file 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,

# Initialize some variables.
dd=`which dd`
pkglibdir=/boot/grub
stage1=$pkglibdir/stage1
stage2=$pkglibdir/stage2

# I like functions.

abort()
{
        /bin/echo -e "\n$@\n" >&2
                exit 1
}

checkfiles()
{
        [ -x "$dd" ] || abort "Can't find $dd, aborting"
        [ -f "$stage1" ] || abort "Can't find $stage1, aborting"
        [ -f "$stage2" ] || abort "Can't find $stage2, aborting"
}

usage()
{
        cat <<EOF
Usage: $0 [options] <block device>
Create GRUB boot floppy.

options:
        -h, --help      print this message and exit

EOF
        exit 1
}

checkdevice()
{
        [ -z "$1" ] && abort "checkdevice() takes block device as parameter"

        [ -b "$1" ] || abort "$1 is not a block device, aborting"
        [ -w "$1" ] || abort "$1 is not a writeable block device, aborting"
}

questiondevice()
{
        [ -z "$1" ] && abort "questiondevice() takes block device as parameter"

        echo "You are about to overwrite the boot sector of the following device:"
        echo "$1"
        echo -n "Are you sure you want to take this action (y/N) "
        read answer
        case "$answer" in
                y* | Y*)
                        # let this fall through to the next function
                        ;;
                *)
                        abort "Not continuing as you wish"
                ;;
        esac
}

createfloppy()
{
        [ -z "$1" ] && abort "createfloppy() takes block device as parameter"

        /bin/echo -e "Creating grub boot floppy now, please be patient ...\n"

        # heres where we actually create the floppy :-p
        $dd if="$stage1" of="$1" bs="512" count="1"
        $dd if="$stage2" of="$1" bs="512" seek="1"

        /bin/echo -e "\nThat's All Folks!"
}

# test we have the necessary files first
checkfiles

case "$1" in
        -h | --help)
                usage
                ;;

        *)
                if [ -z "$1" ] ; then
                        usage
                else
                        checkdevice "$1"
                        questiondevice "$1"
                        createfloppy "$1"
                fi
                ;;
esac

exit 0