#!/bin/sh

set -e

# input is a tarball of vmlinuz64 and initrd.img on stdin
# output is a compressed tarball of a raw disk image on stdout

mkdir -p files
tar xf - -C files

cp syslinux.cfg files

tar cf files.tar -C files .

virt-make-fs --size=1G --type=ext4 --partition files.tar disk.raw

guestfish -a disk.raw -m /dev/sda1 <<EOF
  upload /usr/lib/SYSLINUX/mbr.bin /mbr.bin
  copy-file-to-device /mbr.bin /dev/sda size:440
  rm /mbr.bin
  extlinux /
  part-set-bootable /dev/sda 1 true
EOF

tar cf - disk.raw | gzip -9