#!/bin/sh -e
################################################################################
#
#   Copyright(C) Jonas 'Sortie' Termansen 2015.
#
#   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/>.
#
#   update-initrd
#   Generate a mkinitrd that locates and chain boots the real root filesystem.
#
################################################################################

show_version() {
  cat << EOF
$0 (Sortix)
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF
  exit 0
}


show_help() {
  cat << EOF
Usage: $0 [OPTION]...

Generate a mkinitrd that locates and chain boots the real root filesystem.

Configuration:
  --help              display this help and exit
  --version           display version information and exit
  --sysroot=DIR       operate on this root filesystem [/]
EOF
  exit 0
}

sysroot=

dashdash=
previous_option=
for argument do
  if test -n "$previous_option"; then
    eval $previous_option=\$argument
    previous_option=
    continue
  fi
  case $argument in
  *=?*) parameter=$(expr "X$argument" : '[^=]*=\(.*\)') ;;
  *=)   parameter= ;;
  *)    parameter=yes ;;
  esac
  case $dashdash$argument in
  --) dashdash=yes ;;
  --sysroot=*) sysroot=$parameter ;;
  --sysroot) previous_option=sysroot ;;
  --help) show_help ;;
  --version) show_version ;;
  -*) echo "$0: unrecognized option $argument" >&2
      $option_checking && exit 1 ;;
  *) echo "$0: unexpected operand $argument" >&2
     exit 1 ;;
  esac
done

if [ ! -e "$sysroot/etc/fstab" ]; then
  echo "$0: $sysroot/etc/fstab: Need a filesystem table to make an initrd" >&2
  exit 1
fi
sysmerge=false
exec_prefix="$sysroot"
if [ -d "$sysroot/sysmerge" ]; then
  sysmerge=true
  exec_prefix="$sysroot/sysmerge"
fi
tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT HUP INT QUIT TERM
mkdir "$tmp/bin"
mkdir "$tmp/sbin"
cp "$exec_prefix/sbin/init" "$tmp/sbin"
cp "$exec_prefix/sbin/extfs" "$tmp/sbin"
test -f "$exec_prefix/sbin/fsck.ext2" &&
cp "$exec_prefix/sbin/fsck.ext2" "$tmp/sbin"
mkdir "$tmp/etc"
cp "$sysroot/etc/fstab" "$tmp/etc/fstab"
mkdir "$tmp/etc/init"
if $sysmerge; then
  echo chain-merge > "$tmp/etc/init/target"
else
  echo chain > "$tmp/etc/init/target"
fi
mkdir -p "$sysroot/boot"
mkinitrd --format=sortix-initrd-2 "$tmp" -o "$sysroot/boot/sortix.initrd" > /dev/null