#!/bin/sh
#
# $NetBSD: buildfloppies.sh,v 1.2 2002/04/17 20:42:34 tv Exp $
#
# Copyright (c) 2002 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Luke Mewburn of Wasabi Systems.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#        This product includes software developed by the NetBSD
#        Foundation, Inc. and its contributors.
# 4. Neither the name of The NetBSD Foundation nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

# set defaults
#
: ${PAX=pax}
prog=${0##*/}


usage()
{
	cat 1>&2 << _USAGE_
Usage: ${prog} [-i instboot] [-m max] [-p] base size file [...]
	-i instboot	run instboot to install a bootstrap on @IMAGE@
	-m max		maximum number of floppies to build
	-p		pad last floppy to floppy size
	base		basename of generated floppies
	size		size of a floppy in 512 byte blocks
	file [...]	file(s) to build
_USAGE_
	exit 1
}

plural()
{
	[ $1 -ne 1 ] && echo "s"
}


#	parse and check arguments
#

while getopts i:m:p opt; do
	case ${opt} in
	i)
		instboot=${OPTARG} ;;
	m)
		maxdisks=${OPTARG} ;;
	p)
		pad=1 ;;
	\?|*)
		usage
		;;
	esac
done

shift $(( ${OPTIND} - 1 ))
[ $# -lt 3 ] && usage
floppybase=$1
floppysize=$2
shift 2
files=$*

#	setup temp file, remove existing images
#
floppy=floppy.$$.tar
trap "rm -f ${floppy}" 0 1 2 3			# EXIT HUP INT QUIT
rm -f ${floppybase}?.fs


#	create tar file
#
dd if=/dev/zero of=${floppy} bs=8k count=1 2>/dev/null
${PAX} -w ${files} >> ${floppy} || exit 1
	# XXX: use pax metafile and set perms?
if [ -n "$instboot" ]; then
	instboot=$( echo $instboot | sed -e s/@IMAGE@/${floppy}/ )
	echo "Running instboot: ${instboot}"
	eval ${instboot} || exit 1
fi

#	check size against available number of disks
#
set -- `ls -l ${floppy}`
bytes=$5
blocks=$(( ${bytes} / 512 ))
numdisks=$(( (${blocks} - 1) / ${floppysize} + 1 ))
if [ -z "${maxdisks}" ]; then
	maxdisks=${numdisks}
fi

if [ ${numdisks} -gt ${maxdisks} ]; then
	excess=$(( ( ${blocks} - ${floppysize} * ${maxdisks} ) * 512 ))
	echo 1>&2 \
	    "$prog: Image is ${excess} bytes ($(( ${excess} / 1024 )) KB)"\
	    "too big to fit on ${maxdisks} disk"$(plural ${maxdisks})
	exit 1
fi

if [ -n "${pad}" ]; then
	padsize=$(( ${floppysize} * ${maxdisks} ))
	padcount=$(( ${padsize} - ${blocks} ))
	echo \
	    "Writing $(( ${padsize} * 512 )) bytes ($(( ${padsize} / 2 )) KB)" \
	    "on ${numdisks} disk"$(plural ${numdisks})"," \
	    "padded by $(( ${padcount} * 512 )) bytes" \
	    "($(( ${padcount} / 2 )) KB)"
else
	echo "Writing ${bytes} bytes ($(( ${blocks} / 2 )) KB)"\
	    "on ${numdisks} disk"$(plural ${numdisks})
fi

#	write disks
#
curdisk=1
image=
floppysize8k=$(( ${floppysize} / 16 ))
while [ ${curdisk} -le ${numdisks} ]; do
	image="${floppybase}${curdisk}.fs"
	echo "Creating disk ${curdisk} to ${image}"
	if [ ${curdisk} -eq 1 ]; then
		seek=0
		skip=0
		: > ${image}
	else
		seek=1
		skip=$(( (${curdisk} - 1) * (${floppysize8k} - 1) + 1 ))
		echo USTARFS ${curdisk} > ${image}
	fi
	count=$(( ${floppysize8k} - ${seek} ))
# echo 1>&2 " DEBUG: disk ${curdisk} seek=${seek} skip=${skip} count=${count}"
	dd bs=8k conv=sync seek=${seek} skip=${skip} count=${count} \
	    if=${floppy} of=${image} 2>/dev/null

	curdisk=$(( ${curdisk} + 1 ))
done

#
# XXX:	the old bootfloppy generation code used to zero the last 0.5k of the
#	end of the image in single disk configs; that possibly trashed real
#	data???
#	is that functionality still required?
#

#	pad last disk if necessary
#
if [ -n "${pad}" ]; then
	padseek=$(( ${floppysize} - ${padcount} ))
# echo 1>&2 " DEBUG: padding ${image} with $(( ${padcount} * 512 )) at offset $(( ${padseek} * 512 ))"
	dd seek=${padseek} count=${padcount} \
	    if=/dev/zero of=${image} 2>/dev/null
fi


#	final status
#
echo "Final result:"
ls -l ${floppybase}?.fs

exit 0