#!/bin/bash

# Copyright 2015 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# This will add console=ttyS0 kernel cmdline flag, thus rerouting
# dmesg output to ttyS0 (serial port).
FLAGS_enable_serial=ttyS0
# This will add tty1 console before ttyS0. This way ttyS0
# will be used as a default output for the boot messages from
# userland apps. Kernel messages will go to both outputs (if present)
FLAGS_boot_args="console=tty1"

# Don't install upstart files.
INSTALL_MASK+=" /etc/init"

# Don't install symbol table for kdump kernel.
INSTALL_MASK+=" /boot/kdump/System.map-*"

# Removes given item from the INSTALL_MASK string
remove_from_install_mask(){
  target="$1"
  #Disable wildcard expansion and create array from the INSTALL_MASK string.
  set -f
  INSTALL_MASK_ARRAY=(${INSTALL_MASK})
  set +f
  INSTALL_MASK_NEW=""
  for value in "${INSTALL_MASK_ARRAY[@]}"
  do
    # Remove target from INSTALL_MASK
    if [[ ${value} != "${target}" ]]; then
      INSTALL_MASK_NEW+=" ${value}"
    fi
  done
  INSTALL_MASK="${INSTALL_MASK_NEW}"
  unset INSTALL_MASK_NEW
}

# /boot/config-* is masked in common.sh through INSTALL_MASK which
# prevents installing already generated kernel config. This function
# removes it from the INSTALL_MASK
remove_from_install_mask "/boot/config-*"

# Temporary directory containing the package list
# files used for creating cos-package-info.json.
TEMP_PACKAGE_DIR=""

cleanup_temp_package_dir() {
  if [[ -d "${TEMP_PACKAGE_DIR}" ]]; then
    rm -fr "${TEMP_PACKAGE_DIR}"
  fi
}

# board_make_image_bootable() is invoked as part of build_image after the
# kernel partitions are built and the rootfs is locked. This runs very
# late in the image build process.
board_make_image_bootable() {
  local -r image="$1"
  local -r script_root="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")")"
  . "${script_root}/bootloader_install.sh" || exit 1
  if ! bootloader_install "${image}"; then
    error "Could not install bootloaders on ${image}"
    return 1
  fi
}

create_runtime_package_info() {
  local -r runtime_pkg_file="$1/runtime_pkg_info"

  # The "emerge" command below generates the list of packages that
  # virtual/target-os depends on. These are the packages that are
  # installed into the image. Its results look like
  #
  #   ...
  #   [binary   R    ] app-arch/gzip-1.9 to /build/lakitu/
  #   [binary   R    ] dev-libs/popt-1.16-r2 to /build/lakitu/
  #   [binary   R    ] app-emulation/docker-credential-helpers-0.6.3-r1 to /build/lakitu/
  #   ...
  #
  # This command line is similar to what ListInstalledPackage function (in
  # chromite/licensing/licenses_lib.py) does.
  #
  # The "sed" command extracts the category name, the package name, and the
  # version from each line. With that, the example above is converted to
  #
  #   ...
  #   app-arch/gzip-1.9
  #   dev-libs/popt-1.16-r2
  #   app-emulation/docker-credential-helpers-0.6.3-r1
  #   ...
  "emerge-${BOARD}" \
      --quiet --with-bdeps=n --with-bdeps-auto=n \
      --usepkgonly --emptytree --pretend \
      --color=n virtual/target-os | \
      sed -E 's/\[[^]]+\] (.+) to \/build\/.*/\1/' \
      > "${runtime_pkg_file}"

  echo "${runtime_pkg_file}"
}

create_buildtime_package_info() {
  local -r all_pkg_file="$1/all_pkg_info"

  # The "emerge" command below generates the list of packages that
  # virtual/target-os depends on. It includes both buildtime dependent
  # packages and installed packages. Its results look like
  #
  #   ...
  #   [ebuild   R    ] virtual/pkgconfig-0-r1 to /build/lakitu/
  #   [ebuild   R    ] dev-go/protobuf-1.3.2-r1 to /build/lakitu/
  #   [binary   R    ] app-arch/gzip-1.9 to /build/lakitu/
  #   ...
  #
  # The "sed" command extracts the category name, the package name, and the
  # version from each line. With that, the example above is converted to
  #
  #   ...
  #   virtual/pkgconfig-0-r1
  #   dev-go/protobuf-1.3.2-r1
  #   app-arch/gzip-1.9
  #   ...
  #
  # The "emerge-${BOARD}" command list packages that are either a dependency
  # due to DEPEND or BDEPEND or both. In case of both, multiple entries are
  # present and `sort` and `uniq` are used to avoid that.
  #
  "emerge-${BOARD}" \
      --quiet --with-bdeps=y --with-bdeps-auto=y \
      --emptytree --pretend --color=n \
      virtual/target-os | \
      sed -E 's/\[[^]]+\] ([[:alnum:]_.//-]*).*/\1/' | \
      sort | uniq \
      > "${all_pkg_file}"

  # Package listed above does not include some of the SDK related
  # dependencies such as glibc and gcc. To add those packages,
  # use the package list present at /etc/portage/profile/package.provided
  # under sysroot. It is the same location from where cros_extract_deps
  # gets those package for generation of CPE file.
  local -r pkg_list_file="/build/${BOARD}/etc/portage/profile/package.provided"

  while IFS= read -r line
  do
    # Check for empty line and comment.
    [[ -z "${line}" || "${line}" =~ ^#.* ]] && continue
    echo "${line}" >> "${all_pkg_file}"
  done < "${pkg_list_file}"

  # Find the buildtime dependent packages.
  # Argument $2 represent the file containing the installed packages.
  # All the ebuild files should have a GPL license and therefore,
  # should be distributed in the image. So, there is no need
  # to check whether the package belongs to a public overlay or not.
  local -r buildtime_pkg_file="$1/buildtime_pkg_info"
  fgrep -v -f "$2" "${all_pkg_file}" > "${buildtime_pkg_file}"

  echo "${buildtime_pkg_file}"
}

create_package_info() {
  trap cleanup_temp_package_dir EXIT
  TEMP_PACKAGE_DIR="$(mktemp -d -p /tmp package-list.XXXXXXXXXX)"

  local -r runtime_pkg_file=$(create_runtime_package_info "${TEMP_PACKAGE_DIR}")
  local -r buildtime_pkg_file=$(create_buildtime_package_info \
                                "${TEMP_PACKAGE_DIR}" \
                                "${runtime_pkg_file}")

  local -r script_root="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")")"
  sudo "${script_root}/create_pkg_info.py" \
      --input="installedPackages:${runtime_pkg_file},buildTimePackages:${buildtime_pkg_file}" \
      --output="${root_fs_dir}"/etc/cos-package-info.json \
      --build-id="${CHROMEOS_VERSION_STRING}"

  cleanup_temp_package_dir
  trap - EXIT
}

write_toolchain_path() {
  local -r cros_overlay="/mnt/host/source/src/third_party/chromiumos-overlay"
  local -r sdk_ver_file="${cros_overlay}/chromeos/binhost/host/sdk_version.conf"
  local -r ctarget="$(portageq-"${BOARD}" envvar CHOST)"
  . "${sdk_ver_file}"
  local -r toolchain_path="${TC_PATH/\%\(target\)s/${ctarget}}"
  # Write toolchain path to image.
  echo "${toolchain_path}" | \
      sudo tee "${root_fs_dir}/etc/toolchain-path" > /dev/null
  # Write toolchain path to build dir so it can be exported as an artifact.
  echo "${toolchain_path}" | \
      sudo tee "${BUILD_DIR}/toolchain_path" > /dev/null
}

# Moves the given rootfs file (a relative path to "root_fs_dir") to the given
# artifact location (a relative path to "BUILD_DIR"). The directory containing
# the rootfs file is deleted if it becomes empty after this move. If the
# rootfs file doesn't exist, this function puts an empty file at the given
# artifact location.
move_for_artifact() {
  local rootfs_file="${root_fs_dir}/$1"
  local artifact="${BUILD_DIR}/$2"
  if [[ ! -f "${rootfs_file}" ]]; then
    touch "${artifact}"
    return
  fi
  cp "${rootfs_file}" "${artifact}"
  sudo rm "${rootfs_file}"
  if [[ -z "$(ls -A "$(dirname "${rootfs_file}")")" ]]; then
    sudo rmdir "$(dirname "${rootfs_file}")"
  fi
}

# Creates toolchain_env file in BUILD_DIR so that it can be exported as an
# artifact.
export_toolchain_env() {
  # File that has kernel compiler information.
  move_for_artifact "etc/toolchain_env" "toolchain_env"
}

# Creates kernel_info file in BUILD_DIR so that it can be exported as an
# artifact.
export_kernel_info() {
  # File with kernel information.
  move_for_artifact "etc/kernel_info" "kernel_info"
}

# Creates kernel_commit file in BUILD_DIR so that it can be exported as an
# artifact.
export_kernel_commit() {
  # File with kernel commit ID.
  move_for_artifact "etc/kernel_commit" "kernel_commit"
}

# Export kernel config file as a BUILD artifact.
export_kernel_config(){
  # Copy config file to BUILD_DIR.
  # For example: config-5.10.53
  cp "${root_fs_dir}"/boot/config-* "${BUILD_DIR}/kernel_config"
}

# Exports default GPU driver version file as an artifact.
export_gpu_default_version() {
  local -r script_root="$1"
  local -r default_driver_file="${script_root}/gpu_default_version"
  local -r default_driver_artifact="${BUILD_DIR}/gpu_default_version"

  # Copy scripts/gpu_default_version to BUILD artifact
  cp "${default_driver_file}" "${default_driver_artifact}"
}

# Exports latest GPU driver version file as an artifact.
export_gpu_latest_version() {
  local -r script_root="$1"
  local -r latest_driver_file="${script_root}/gpu_latest_version"
  local -r latest_driver_artifact="${BUILD_DIR}/gpu_latest_version"

  # Copy scripts/gpu_latest_version to BUILD artifact
  cp "${latest_driver_file}" "${latest_driver_artifact}"
}

# Apply recommended file permissions by CIS Benchmark
change_file_permissions_for_cis()  {
  # set permissions of systemd timer files as recommended by CIS
  sudo find "${root_fs_dir}"/usr/lib/systemd/user \
    "${root_fs_dir}"/usr/lib/systemd/system \
    "${root_fs_dir}"/lib/systemd/system \
    -type f -name *.timer | xargs sudo chmod go-wrx

  # Set grub.cfg file permissions to 400 as recommended by CIS
  if [[ -f "${root_fs_dir}"/boot/efi/boot/grub.cfg ]]; then
    sudo chmod 400 "${root_fs_dir}"/boot/efi/boot/grub.cfg
  fi

  # Set /root dir permissions to 750 as recommended by CIS
  if [[ -d "${root_fs_dir}"/root ]]; then
    sudo chmod 750 "${root_fs_dir}"/root
  fi
}

# board_finalize_base_image() is invoked as part of build_image before the
# rootfs is locked. Some rootfs changes have been made before this, and more
# rootfs changes are made after this.
board_finalize_base_image() {
  local -r script_root="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")")"
  info "Generating cos-package-info.json."
  (create_package_info)
  cp "${root_fs_dir}"/etc/cos-package-info.json \
     "${BUILD_DIR}"/cos-package-info.json
  write_toolchain_path
  move_for_artifact "opt/google/src/kernel-src.tar.gz" \
                    "kernel-src.tar.gz"
  move_for_artifact "opt/google/src/kernel-headers.tgz" \
                    "kernel-headers.tgz"
  export_toolchain_env
  export_kernel_info
  export_kernel_commit
  export_kernel_config
  cp "${BOARD_ROOT}/usr/lib/debug/boot/vmlinux" "${BUILD_DIR}/vmlinux"
  export_gpu_default_version "${script_root}"
  export_gpu_latest_version "${script_root}"

  # /etc/machine-id gets installed by sys-apps/dbus and is a symlink.
  # This conflicts with systemd's machine-id generation mechanism,
  # so we remove the symlink and recreate it as an empty file.
  sudo rm "${root_fs_dir}"/etc/machine-id
  sudo touch "${root_fs_dir}"/etc/machine-id

  change_file_permissions_for_cis

  local shim_arch=""
  if [[ "${ARCH}" == "amd64" ]]; then
    shim_arch="x64"
  elif [[ "${ARCH}" == "arm64" ]]; then
    shim_arch="aa64"
  else
    error "Unsupported architecture. No shim. ARCH=${ARCH}"
    return 1
  fi
  info "Copying shim to boot${shim_arch}.efi"
  sudo cp \
    "${root_fs_dir}/boot/efi/boot/shim${shim_arch}.efi" \
    "${root_fs_dir}/boot/efi/boot/boot${shim_arch}.efi"
  info "Successfully copied shim to boot${shim_arch}.efi"

  info "Deleting legacy EFI bootloaders"
  # Don't delete bootx64.efi here, since it can be the shim now.
  sudo rm -f "${root_fs_dir}"/boot/efi/boot/bootia32.efi
  info "Successfully deleted legacy EFI bootloaders"
}

# Align images to 1MB page size.
# Azure image requires 1MB page size alignment; while
# MTest and VIT image requires 4K page size alignment.
# We use 1MB as the image alignment and apply to all
# images since nowadays, most storage is aligned to 4096 instead of 512.
# Also COS image is used as virtual image in hypervisor/cloud
# environment.
align_image_to_1m() {
  local base_image="$1"
  local size
  local mod
  local new_size
  echo "Aligning to 1MiB to meet Azure/Mtest/VIT requirements"
  size="$(stat --printf "%s" "${base_image}")"
  mod="$(( size % (1 << 20) ))"
  if [[ "${mod}" != 0 ]]; then
    new_size="$(( (1 << 20) - mod + size ))"
    qemu-img resize "${base_image}" "${new_size}"
    # Might need to relocate the secondary GPT headers
    cgpt repair "${base_image}"
  fi
}

# board_setup() is invoked as part of build_image when the base image is
# completely finished.
board_setup() {
  local base_image="$1"
  align_image_to_1m "${base_image}"
}