#!/bin/bash -e
# Tiny Linux Bootloader
# (c) 2014- Dr Gareth Owen (www.ghowen.me). All rights reserved.

#    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 3 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, see <http://www.gnu.org/licenses/>.

INPUT="bsect.asm"
OUTPUT="disk"
KERN="./barebones"
RD="./big.init"

#size of kern + ramdisk
K_SZ=`stat -c %s $KERN`
R_SZ=`stat -c %s $RD`

#padding to make it up to a sector
K_PAD=$((512 - $K_SZ % 512))
R_PAD=$((512 - $R_SZ % 512))

nasm -o $OUTPUT -D initRdSizeDef=$R_SZ $INPUT
cat $KERN >> $OUTPUT
if [[ $K_PAD -lt 512 ]]; then
    dd if=/dev/zero bs=1 count=$K_PAD >> $OUTPUT
fi

cat $RD >> $OUTPUT
if [[ $R_PAD -lt 512 ]]; then
    dd if=/dev/zero bs=1 count=$R_PAD >> $OUTPUT
fi

TOTAL=`stat -c %s $OUTPUT`
echo "concatenated bootloader, kernel and initrd into ::> $OUTPUT"
echo "Note, your first partition must start after sector $(($TOTAL / 512))"

