#!/bin/sh

_root="$(dirname "${0}")"; . "${_root}/lib/env.sh"
want root log

pebkac(){
  [ "${*}" ] && echo "$(basename "${0}"): ${*}" && echo ""
  echo "Generate a card image using the specified boot and root images,"
  echo " and the optional conf directory to fill the free space."
  echo ""
  echo "Options:"
  echo " -b <image>  Boot image filename (default boot.img)"
  echo " -r <image>  Root image filename (default root.img)"
  echo " -c <dir>    Config directory to embed into card image"
  echo " -o <image>  Card image filename to write (default card.img)"
  echo " -s <bytes>  Intended card size, in 512-byte sectors"
  echo " -h          Hi!"
  exit 1
}

img_sects(){
  [ ! -f "${1}" ] && return 0
  (
    eval $(stat -s "${1}")
    echo "$(( ( ${st_size} + ( ${st_size} % 512 ) ) / 512 ))"
  )
}

compute_label(){
  # Params: 1: cardsects 2: boot.img 3: root.img
  card_size="${1}"
  boot_file="${2}"
  root_file="${3}"
  [ -z "${card_size}" -o -z "${boot_file}" -o -z "${root_file}" ] && pebkac "RTFS, bitch!"
  
  omfg_ofst=0
  omfg_size=16
  boot_ofst="$(( ${omfg_ofst} + ${omfg_size} ))"
  boot_size="$(img_sects boot.img)"
  root_ofst="$(( ${boot_ofst} + ${boot_size} ))"
  root_size="$(img_sects root.img)"
  conf_ofst="$(( ${root_ofst} + ${root_size} ))"
  conf_size="$(( ${card_size} - ( ${omfg_size} + ${boot_size} + ${root_size} ) ))"
  last_ofst="$(( ${conf_ofst} + ${conf_size} ))"
  
  echo "a: ${boot_size} ${boot_ofst} 4.2BSD"
  echo "c: ${card_size} 0 unused"
  echo "d: ${root_size} ${root_ofst} 4.2BSD"
  echo "e: ${conf_size} ${conf_ofst} 4.2BSD"
}

# Defaults
boot_img="boot.img"
root_img="root.img"
conf_dir="conf"
card_img="card.img"
card_size=1000944

# Parse command line options
while getopts "b:r:c:o:s:h" opt
do
  case "${opt}" in
    b) boot_img="${OPTARG}" ;;
    r) root_img="${OPTARG}" ;;
    c) conf_dir="${OPTARG}" ;;
    o) card_img="${OPTARG}" ;;
    s) card_size="${OPTARG}" ;;
    h) pebkac ;;
    [?]) pebkac "Unrecognized option ${opt}" ;;
  esac
done
shift $(( $OPTIND - 1 ))

[ -f "${boot_img}" ] || err "${boot_img}: no such file or directory"
[ -f "${root_img}" ] || err "${root_img}: no such file or directory"
[ -d "${conf_dir}" ] || err "${conf_dir}: not a directory"
[ "${card_size}" -gt 0 ] || err "${card_size}: not a number "

log Card size: ${card_size} sectors
rm -f "${card_img}"
dd if=/dev/zero of="${card_img}" bs=512 count=0 seek="${card_size}" 2>/dev/null
md=$(mdconfig -a -t vnode -f "${card_img}")
mnt="$(mktemp -d /tmp/conf.XXXXXXXX)"
trap "umount '${mnt}'; rmdir '${mnt}'; mdconfig -d -u '${md}'" exit hup int term kill

compute_label "${card_size}" "${boot_img}" "${root_img}" | bsdlabel -R -B "${md}" /dev/stdin
log Applied label:
bsdlabel "${md}"

log Writing boot image from "${boot_img}"
dd if="${boot_img}" of="/dev/${md}a" bs=131072 2>/dev/null

log Writing root image from "${root_img}"
dd if="${root_img}" of="/dev/${md}d" bs=131072 2>/dev/null

log Writing conf image
newfs -U -L conf "/dev/${md}e"

log Populating conf from "${conf_dir}"
mount "/dev/${md}e" "${mnt}"
( cd "${conf_dir}"; find . | cpio -p "${mnt}" )

sync