#!/bin/sh

set -e

mkdir -p /tmp/iso
cd /tmp/iso

# input is a tarball of filesystem on stdin with kernel in /boot
# output is an iso on stdout

# extract. BSD tar auto recognises compression, unlike GNU tar
# only if stdin is a tty, if so need files volume mounted...
[ -t 0 ] || bsdtar xzf -

CMDLINE="$(cat boot/cmdline)"
# if no root= root device specified, assume /dev/sr0 ie first CD drive
echo "${CMDLINE}" | grep -q 'root=' || CMDLINE="${CMDLINE} root=/dev/sr0"
rm boot/cmdline

mkdir -p isolinux
cp /usr/share/syslinux/isolinux.bin ./isolinux/
cp /usr/share/syslinux/ldlinux.c32 ./isolinux/

CFG="DEFAULT linux
LABEL linux
    KERNEL /boot/kernel
    APPEND ${CMDLINE}
"

printf "$CFG" > isolinux/isolinux.cfg

genisoimage -o ../linuxkit-bios.iso -l -J -R \
                -c isolinux/boot.cat  \
                -b isolinux/isolinux.bin \
                   -no-emul-boot -boot-load-size 4 -boot-info-table \
		-joliet-long -input-charset utf8 \
                -V LinuxKit .

isohybrid ../linuxkit-bios.iso

cat ../linuxkit-bios.iso