refind-genconf

#!/bin/bash
#shellcheck disable=2034

# Yo, I heard you like confs, so here's a conf for your conf.
#
# Copyright (c) 2021 Maddison Hellstrom (github.com/b0o)
#
# 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 <https://www.gnu.org/licenses/>.

set -euo pipefail
shopt -s inherit_errexit

declare prog
prog="$(basename "${BASH_SOURCE[0]}")"

declare -i indent=0
declare conf

declare -g boot
declare -g menu_title
declare -ga conf_outer
declare -ga conf_inner
declare -ga boot_types
declare -g default_kernel
declare -g default_type
declare -ga kernels
declare -g indent_char
declare -gi indent_size

function default_conf() {
  cat >&2 << EOF
# Default configuration for $prog

# Path to the boot partition mount point.
# Default:
# boot="/boot"

# Title of the main refind linux menu. If not specified, it will be autodetected via lsb_release.
# menu_title=""

# Configuration directives to be placed at the outermost level of the refind config file.
# Default:
# conf_outer=()

# Configuration directives to be placed within the main refind linux menu
# Default:
# conf_inner=()

# The different boot types for which you would like to generate boot submenu entries.
# Boot type names should match the regular expression [a-zA-Z0-9_]+. The boot type "all" is reserved.
# Default:
# boot_types=("basic" "fallback")

# Manually specify for which kernels boot entries should be generated.
# If this array is empty, all installed kernels will have boot entries generated for them.
# Default:
# kernels=()

# The default kernel to use.
# Default:
# default_kernel="linux"

# The default boot type to use.
# Default:
# default_type="basic"

# Kernel parameters to pass for all boot types.
# Default:
# params_all=()

# To define kernel parameters specific to a given boot type, define an array
# named params_\${boot_type}, e.g. params_basic.

# Character to use for indentation, either a tab or a space.
# Default:
# indent_char=" "

# Number of indent characters per indent level.
# Default:
# indent_size=2

EOF
}

function example_conf() {
  cat >&2 << EOF
# Example configuration for $prog
# Make sure you edit this file to reflect your actual setup!

# Path to the boot partition mount point.
# Default:
# boot="/boot"

# Title of the main refind linux menu. If not specified, it will be autodetected via lsb_release.
# menu_title="Arch Linux"

# Configuration directives to be placed at the outermost level of the refind config file.
# Default:
# conf_outer=()
conf_outer=(
  "include /EFI/refind/themes/refind-ambience/theme.conf"
  "icons_dir /EFI/refind/themes/refind-ambience/icons"
  "scan_all_linux_kernels false"
  "timeout 20"
  "screensaver 300"
)

# Configuration directives to be placed within the main refind linux menu
# Default:
# conf_inner=()
conf_inner=(
  "icon /EFI/refind/themes/refind-ambience/icons/os_arch.png"
  'volume "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"'
)

# The different boot types for which you would like to generate boot submenu entries.
# Boot type names should match the regular expression [a-zA-Z0-9_]+. The boot type "all" is reserved.
# Default:
# boot_types=("basic" "fallback")
boot_types=(
  "apparmor"
  "basic"
  "minimal"
  "fallback"
)

# Manually specify for which kernels boot entries should be generated.
# If this array is empty, all installed kernels will have boot entries generated for them.
kernels=("linux-clear-bin" "linux-ck-zen" "linux-zen" "linux")

# The default kernel to use.
# Default:
# default_kernel="linux"
default_kernel="linux-ck-zen"

# The default boot type to use.
# Default:
# default_type="basic"
default_type="apparmor"

# Kernel parameters to pass for all boot types.
# Default:
# params_all=()
params_all=(
  "ro"
  "rd.luks.uuid=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  "rd.luks.name=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx=system"
  "root=/dev/mapper/system"
  "rootflags=subvol=@"
)

# To define kernel parameters specific to a given boot type, define an array
# named params_\${boot_type}, e.g. params_basic.

# Kernel parameters to pass for the 'basic' boot type.
params_basic=(
  "splash"
  "quiet"
  "consoleblank=60"
  "fbcon=scrollback:256k"
  "initrd=\\\\amd-ucode.img"
)

# Kernel parameters to pass for the 'apparmor' boot type.
params_apparmor=(
  "\${params_basic[@]}"
  "apparmor=1"
  "security=apparmor"
)

# Kernel parameters to pass for the 'minimal' boot type.
params_minimal=(
  "nosplash"
)

# Kernel parameters to pass for the 'fallback' boot type.
params_fallback=(
  "\${params_minimal[@]}"
)

# Character to use for indentation, either a tab or a space.
# Default:
# indent_char=" "

# Number of indent characters per indent level.
# Default:
# indent_size=2

EOF
}

function load_conf() {
  if [[ -n "${conf:-}" ]]; then
    # shellcheck disable=1090
    source "$conf" || {
      echo "$prog: unable to load configuration file" >&2
      return 1
    }
  fi

  # Path to the boot partition mount point.
  [[ -v boot ]] || {
    declare -g boot=""
    if [[ -d "/boot" ]]; then
      boot="/boot"
    fi
  }

  # Title for the main refind menu item
  [[ -v menu_title && -n "${menu_title}" ]] || {
    menu_title="$(lsb_release -sd | tr -d '"')"
  }

  # Configuration directives to be placed at the outermost level of the refind config file.
  [[ -v conf_outer ]] || conf_outer=()

  # Configuration directives to be placed within the main refind linux menu
  [[ -v conf_inner ]] || conf_inner=()

  # The default kernel to use.
  [[ -v default_kernel ]] || default_kernel="linux"

  # The different boot types for which you would like to generate boot submenu entries.
  [[ -v boot_types ]] || boot_types=(
    "basic"
    "fallback"
  )

  if [[ ! -v default_type && -v 'boot_types[0]' ]]; then
    # The default boot type to use.
    default_type="${boot_types[0]}"
  fi

  # Parameters which should be passed for all boot types
  [[ -v params_all ]] || params_all=()

  # Manually specify for which kernels boot entries should be generated.
  # If this array is empty, all installed kernels will have boot entries generated for them.
  [[ -v kernels ]] || kernels=()

  # Character to use for indentation, either a tab or a space.
  [[ -v indent_char ]] || indent_char=" "

  # Number of indent characters per indent level.
  [[ -v indent_size ]] || indent_size=2
}

function out() {
  local -i i=$((indent * indent_size))
  [[ $i -ge 1 && -n "$*" ]] && printf "${indent_char}%.0s" $(seq 1 $i)
  echo "$*"
}

function submenu() {
  [[ $# -eq 3 ]] || {
    echo "submenu: expected 3 arguments, got $#" >&2
    return 1
  }
  local -i submenu=$1
  local kernel="$2"
  local type="$3"
  if [[ $submenu -eq 1 ]]; then
    out "submenuentry \"$kernel ($type)\" {"
    indent=$((indent + 1))
  fi
}

function submenu_end() {
  [[ $# -eq 1 ]] || {
    echo "submenu: expected 1 arguments, got $#" >&2
    return 1
  }
  local -i submenu=$1
  if [[ $submenu -eq 1 ]]; then
    indent=$((indent - 1))
    out "}"
  fi
}

function entry() {
  local -i submenu=0

  local opt OPTARG
  local -i OPTIND
  while getopts "s" opt "$@"; do
    case "$opt" in
    s)
      submenu=1
      ;;
    \?)
      return 1
      ;;
    esac
  done
  shift $((OPTIND - 1))

  [[ $# -eq 2 ]] || {
    echo "entry: expected 2 args, got $#" >&2
    return 1
  }

  local type="$1"
  local kernel="$2"

  if [[ -v "params_$type" ]]; then
    local -n params="params_$type"
  else
    local -a params=()
  fi

  local loader="vmlinuz-${kernel}"

  local initrd
  if [[ $type == "fallback" ]]; then
    initrd="initramfs-${kernel}-fallback.img"
  else
    initrd="initramfs-${kernel}.img"
  fi

  submenu $submenu "$kernel" "$type"
  out "loader  /${loader}"
  out "options \"initrd=\\${initrd}${params:+ ${params[*]}}${params_all:+ ${params_all[*]}}\""
  submenu_end $submenu
}

function usage() {
  cat >&2 << EOF
usage: $prog [opts] [kernel ..]

Options:

  -h            Print this help message.
  -c <config>   Use <config> file to configure refind-genconf (wow such config).
  -x            Print the default configuration file.
  -X            Print an example configuration file.

$prog generates refind configuration files
EOF
}

function main() {
  local opt OPTARG
  local -i OPTIND
  while getopts "hxXc:" opt "$@"; do
    case "$opt" in
    h)
      usage
      return 0
      ;;
    x)
      default_conf
      return 0
      ;;
    X)
      example_conf
      return 0
      ;;
    c)
      conf="$OPTARG"
      ;;
    \?)
      return 1
      ;;
    esac
  done
  shift $((OPTIND - 1))

  load_conf

  if [[ $# -gt 0 ]]; then
    kernels=("$@")
  fi

  if [[ ${#kernels[@]} -eq 0 ]]; then
    mapfile -t kernels <<< "$(
      find "$boot" -mindepth 1 -maxdepth 1 -type f -name 'initramfs*.img' -a '!' -name '*-fallback.img' -exec basename '{}' ';' \
        | sed 's/^initramfs-//; s/\.img$//'
    )"
  fi

  out "# NOTE: This file was auto-generated by $prog. Do not edit directly."
  out

  for l in "${conf_outer[@]}"; do
    out "$l"
  done

  [[ ${#conf_outer[@]} -gt 0 ]] && out

  out "menuentry \"${menu_title}\" {"

  indent=$((indent + 1))

  out "ostype \"Linux\""

  for l in "${conf_inner[@]}"; do
    out "$l"
  done

  [[ -v default_kernel && -v default_type ]] && {
    out
    out "# Default: $default_kernel ($default_type)"
    entry "$default_type" "$default_kernel"
  }

  for kernel in "${kernels[@]}"; do
    out
    out "# $kernel {{{"
    out
    for type in "${boot_types[@]}"; do
      entry -s "$type" "$kernel"
      out
    done
    out "# }}}"
  done

  indent=$((indent - 1))

  out "}"
  out

  indent=0

  # Output a vim modeline at the bottom of the refind conf
  # The following line uses a weird string concatenation trick to prevent vim
  # from using it as the modeline for this script.
  out "# v""im:set fdm=marker fdl=2 ft=conf sw=2 sts=2 et:"
}

main "$@"