calamares/src/modules/bootloader/main.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# === This file is part of Calamares - <https://calamares.io> ===
#
#   SPDX-FileCopyrightText: 2014 Aurélien Gâteau <agateau@kde.org>
#   SPDX-FileCopyrightText: 2014 Anke Boersma <demm@kaosx.us>
#   SPDX-FileCopyrightText: 2014 Daniel Hillenbrand <codeworkx@bbqlinux.org>
#   SPDX-FileCopyrightText: 2014 Benjamin Vaudour <benjamin.vaudour@yahoo.fr>
#   SPDX-FileCopyrightText: 2014-2019 Kevin Kofler <kevin.kofler@chello.at>
#   SPDX-FileCopyrightText: 2015-2018 Philip Mueller <philm@manjaro.org>
#   SPDX-FileCopyrightText: 2016-2017 Teo Mrnjavac <teo@kde.org>
#   SPDX-FileCopyrightText: 2017 Alf Gaida <agaida@siduction.org>
#   SPDX-FileCopyrightText: 2017-2019 Adriaan de Groot <groot@kde.org>
#   SPDX-FileCopyrightText: 2017 Gabriel Craciunescu <crazy@frugalware.org>
#   SPDX-FileCopyrightText: 2017 Ben Green <Bezzy1999@hotmail.com>
#   SPDX-FileCopyrightText: 2021 Neal Gompa <ngompa13@gmail.com>
#   SPDX-License-Identifier: GPL-3.0-or-later
#
#   Calamares is Free Software: see the License-Identifier above.
#

import os
import shutil
import subprocess

import libcalamares

from libcalamares.utils import check_target_env_call


import gettext
_ = gettext.translation("calamares-python",
                        localedir=libcalamares.utils.gettext_path(),
                        languages=libcalamares.utils.gettext_languages(),
                        fallback=True).gettext

# This is the sanitizer used all over to tidy up filenames
# to make identifiers (or to clean up names to make filenames).
file_name_sanitizer = str.maketrans(" /()", "_-__")

def pretty_name():
    return _("Install bootloader.")


def get_uuid():
    """
    Checks and passes 'uuid' to other routine.

    :return:
    """
    partitions = libcalamares.globalstorage.value("partitions")

    for partition in partitions:
        if partition["mountPoint"] == "/":
            libcalamares.utils.debug("Root partition uuid: \"{!s}\"".format(partition["uuid"]))
            return partition["uuid"]

    return ""


def get_bootloader_entry_name():
    """
    Passes 'bootloader_entry_name' to other routine based
    on configuration file.

    :return:
    """
    if "bootloaderEntryName" in libcalamares.job.configuration:
        return libcalamares.job.configuration["bootloaderEntryName"]
    else:
        branding = libcalamares.globalstorage.value("branding")
        return branding["bootloaderEntryName"]


def get_kernel_line(kernel_type):
    """
    Passes 'kernel_line' to other routine based on configuration file.

    :param kernel_type:
    :return:
    """
    if kernel_type == "fallback":
        if "fallbackKernelLine" in libcalamares.job.configuration:
            return libcalamares.job.configuration["fallbackKernelLine"]
        else:
            return " (fallback)"
    else:
        if "kernelLine" in libcalamares.job.configuration:
            return libcalamares.job.configuration["kernelLine"]
        else:
            return ""


def create_systemd_boot_conf(install_path, efi_dir, uuid, entry, entry_name, kernel_type):
    """
    Creates systemd-boot configuration files based on given parameters.

    :param install_path:
    :param efi_dir:
    :param uuid:
    :param entry:
    :param entry_name:
    :param kernel_type:
    """
    kernel = libcalamares.job.configuration["kernel"]
    kernel_params = ["quiet"]

    partitions = libcalamares.globalstorage.value("partitions")
    swap_uuid = ""
    swap_outer_mappername = None

    cryptdevice_params = []

    # Take over swap settings:
    #  - unencrypted swap partition sets swap_uuid
    #  - encrypted root sets cryptdevice_params
    for partition in partitions:
        if partition["fs"] == "linuxswap" and not partition.get("claimed", None):
            continue
        has_luks = "luksMapperName" in partition
        if partition["fs"] == "linuxswap" and not has_luks:
            swap_uuid = partition["uuid"]

        if (partition["fs"] == "linuxswap" and has_luks):
            swap_outer_mappername = partition["luksMapperName"]

        if partition["mountPoint"] == "/" and has_luks:
            cryptdevice_params = ["cryptdevice=UUID="
                                  + partition["luksUuid"]
                                  + ":"
                                  + partition["luksMapperName"],
                                  "root=/dev/mapper/"
                                  + partition["luksMapperName"]]

    if cryptdevice_params:
        kernel_params.extend(cryptdevice_params)
    else:
        kernel_params.append("root=UUID={!s}".format(uuid))

    if swap_uuid:
        kernel_params.append("resume=UUID={!s}".format(swap_uuid))

    if swap_outer_mappername:
        kernel_params.append("resume=/dev/mapper/{!s}".format(
            swap_outer_mappername))

    kernel_line = get_kernel_line(kernel_type)
    libcalamares.utils.debug("Configure: \"{!s}\"".format(kernel_line))

    if kernel_type == "fallback":
        img = libcalamares.job.configuration["fallback"]
        entry_name = entry_name + "-fallback"
    else:
        img = libcalamares.job.configuration["img"]

    conf_path = os.path.join(install_path + efi_dir,
                             "loader",
                             "entries",
                             entry_name + ".conf")

    # Copy kernel and initramfs to a subdirectory of /efi partition
    files_dir = os.path.join(install_path + efi_dir, entry_name)
    os.mkdir(files_dir)

    kernel_path = install_path + kernel
    kernel_name = os.path.basename(kernel_path)
    shutil.copyfile(kernel_path, os.path.join(files_dir, kernel_name))

    img_path = install_path + img
    img_name = os.path.basename(img_path)
    shutil.copyfile(img_path, os.path.join(files_dir, img_name))

    lines = [
        '## This is just an example config file.\n',
        '## Please edit the paths and kernel parameters according\n',
        '## to your system.\n',
        '\n',
        "title   {!s}{!s}\n".format(entry, kernel_line),
        "linux   {!s}\n".format(os.path.join("/", entry_name, kernel_name)),
        "initrd  {!s}\n".format(os.path.join("/", entry_name, img_name)),
        "options {!s} rw\n".format(" ".join(kernel_params)),
    ]

    with open(conf_path, 'w') as conf_file:
        for line in lines:
            conf_file.write(line)


def create_loader(loader_path, entry):
    """
    Writes configuration for loader.

    :param loader_path:
    :param entry:
    """
    timeout = libcalamares.job.configuration["timeout"]
    lines = [
        "timeout {!s}\n".format(timeout),
        "default {!s}\n".format(entry),
    ]

    with open(loader_path, 'w') as loader_file:
        for line in lines:
            loader_file.write(line)


def efi_label():
    if "efiBootloaderId" in libcalamares.job.configuration:
        efi_bootloader_id = libcalamares.job.configuration[
                                "efiBootloaderId"]
    else:
        branding = libcalamares.globalstorage.value("branding")
        efi_bootloader_id = branding["bootloaderEntryName"]

    return efi_bootloader_id.translate(file_name_sanitizer)


def efi_word_size():
    # get bitness of the underlying UEFI
    try:
        sysfile = open("/sys/firmware/efi/fw_platform_size", "r")
        efi_bitness = sysfile.read(2)
    except Exception:
        # if the kernel is older than 4.0, the UEFI bitness likely isn't
        # exposed to the userspace so we assume a 64 bit UEFI here
        efi_bitness = "64"
    return efi_bitness


def efi_boot_next():
    """
    Tell EFI to definitely boot into the just-installed
    system next time.
    """
    boot_mgr = libcalamares.job.configuration["efiBootMgr"]
    boot_entry = None
    efi_bootvars = subprocess.check_output([boot_mgr], text=True)
    for line in efi_bootvars.split('\n'):
        if not line:
            continue
        words = line.split()
        if len(words) >= 2 and words[0] == "BootOrder:":
            boot_entry = words[1].split(',')[0]
            break
    if boot_entry:
        subprocess.call([boot_mgr, "-n", boot_entry])


def install_systemd_boot(efi_directory):
    """
    Installs systemd-boot as bootloader for EFI setups.

    :param efi_directory:
    """
    libcalamares.utils.debug("Bootloader: systemd-boot")
    install_path = libcalamares.globalstorage.value("rootMountPoint")
    install_efi_directory = install_path + efi_directory
    uuid = get_uuid()
    distribution = get_bootloader_entry_name()
    distribution_translated = distribution.translate(file_name_sanitizer)
    loader_path = os.path.join(install_efi_directory,
                               "loader",
                               "loader.conf")
    subprocess.call(["bootctl",
                     "--path={!s}".format(install_efi_directory),
                     "install"])
    create_systemd_boot_conf(install_path,
                             efi_directory,
                             uuid,
                             distribution,
                             distribution_translated,
                             "default")
    if "fallback" in libcalamares.job.configuration:
        create_systemd_boot_conf(install_path,
                                 efi_directory,
                                 uuid,
                                 distribution,
                                 distribution_translated,
                                 "fallback")
    create_loader(loader_path, distribution_translated)


def install_grub(efi_directory, fw_type):
    """
    Installs grub as bootloader, either in pc or efi mode.

    :param efi_directory:
    :param fw_type:
    """
    if fw_type == "efi":
        libcalamares.utils.debug("Bootloader: grub (efi)")
        install_path = libcalamares.globalstorage.value("rootMountPoint")
        install_efi_directory = install_path + efi_directory

        if not os.path.isdir(install_efi_directory):
            os.makedirs(install_efi_directory)

        efi_bootloader_id = efi_label()
        efi_bitness = efi_word_size()

        if efi_bitness == "32":
            efi_target = "i386-efi"
            efi_grub_file = "grubia32.efi"
            efi_boot_file = "bootia32.efi"
        elif efi_bitness == "64":
            efi_target = "x86_64-efi"
            efi_grub_file = "grubx64.efi"
            efi_boot_file = "bootx64.efi"

        check_target_env_call([libcalamares.job.configuration["grubInstall"],
                               "--target=" + efi_target,
                               "--efi-directory=" + efi_directory,
                               "--bootloader-id=" + efi_bootloader_id,
                               "--force"])

        # VFAT is weird, see issue CAL-385
        install_efi_directory_firmware = (vfat_correct_case(
                                              install_efi_directory,
                                              "EFI"))
        if not os.path.exists(install_efi_directory_firmware):
            os.makedirs(install_efi_directory_firmware)

        # there might be several values for the boot directory
        # most usual they are boot, Boot, BOOT

        install_efi_boot_directory = (vfat_correct_case(
                                          install_efi_directory_firmware,
                                          "boot"))
        if not os.path.exists(install_efi_boot_directory):
            os.makedirs(install_efi_boot_directory)

        # Workaround for some UEFI firmwares
        FALLBACK = "installEFIFallback"
        libcalamares.utils.debug("UEFI Fallback: " + str(libcalamares.job.configuration.get(FALLBACK, "<unset>")))
        if libcalamares.job.configuration.get(FALLBACK, True):
            libcalamares.utils.debug("  .. installing '{!s}' fallback firmware".format(efi_boot_file))
            efi_file_source = os.path.join(install_efi_directory_firmware,
                                        efi_bootloader_id,
                                        efi_grub_file)
            efi_file_target = os.path.join(install_efi_boot_directory,
                                        efi_boot_file)

            shutil.copy2(efi_file_source, efi_file_target)
    else:
        libcalamares.utils.debug("Bootloader: grub (bios)")
        if libcalamares.globalstorage.value("bootLoader") is None:
            return

        boot_loader = libcalamares.globalstorage.value("bootLoader")
        if boot_loader["installPath"] is None:
            return

        check_target_env_call([libcalamares.job.configuration["grubInstall"],
                               "--target=i386-pc",
                               "--recheck",
                               "--force",
                               boot_loader["installPath"]])

    # The input file /etc/default/grub should already be filled out by the
    # grubcfg job module.
    check_target_env_call([libcalamares.job.configuration["grubMkconfig"],
                           "-o", libcalamares.job.configuration["grubCfg"]])


def install_secureboot(efi_directory):
    """
    Installs the secureboot shim in the system by calling efibootmgr.
    """
    efi_bootloader_id = efi_label()

    install_path = libcalamares.globalstorage.value("rootMountPoint")
    install_efi_directory = install_path + efi_directory

    if efi_word_size() == "64":
        install_efi_bin = "shimx64.efi"
    elif efi_word_size() == "32":
        install_efi_bin = "shimia32.efi"

    # Copied, roughly, from openSUSE's install script,
    # and pythonified. *disk* is something like /dev/sda,
    # while *drive* may return "(disk/dev/sda,gpt1)" ..
    # we're interested in the numbers in the second part
    # of that tuple.
    efi_drive = subprocess.check_output([
        libcalamares.job.configuration["grubProbe"],
        "-t", "drive", "--device-map=", install_efi_directory]).decode("ascii")
    efi_disk = subprocess.check_output([
        libcalamares.job.configuration["grubProbe"],
        "-t", "disk", "--device-map=", install_efi_directory]).decode("ascii")

    efi_drive_partition = efi_drive.replace("(","").replace(")","").split(",")[1]
    # Get the first run of digits from the partition
    efi_partition_number = None
    c = 0
    start = None
    while c < len(efi_drive_partition):
        if efi_drive_partition[c].isdigit() and start is None:
            start = c
        if not efi_drive_partition[c].isdigit() and start is not None:
            efi_partition_number = efi_drive_partition[start:c]
            break
        c += 1
    if efi_partition_number is None:
        raise ValueError("No partition number found for %s" % install_efi_directory)

    subprocess.call([
        libcalamares.job.configuration["efiBootMgr"],
        "-c",
        "-w",
        "-L", efi_bootloader_id,
        "-d", efi_disk,
        "-p", efi_partition_number,
        "-l", install_efi_directory + "/" + install_efi_bin])

    efi_boot_next()

    # The input file /etc/default/grub should already be filled out by the
    # grubcfg job module.
    check_target_env_call([libcalamares.job.configuration["grubMkconfig"],
                           "-o", os.path.join(efi_directory, "EFI",
                                              efi_bootloader_id, "grub.cfg")])


def vfat_correct_case(parent, name):
    for candidate in os.listdir(parent):
        if name.lower() == candidate.lower():
            return os.path.join(parent, candidate)
    return os.path.join(parent, name)


def prepare_bootloader(fw_type):
    """
    Prepares bootloader.
    Based on value 'efi_boot_loader', it either calls systemd-boot
    or grub to be installed.

    :param fw_type:
    :return:
    """
    efi_boot_loader = libcalamares.job.configuration["efiBootLoader"]
    efi_directory = libcalamares.globalstorage.value("efiSystemPartition")

    if efi_boot_loader == "systemd-boot" and fw_type == "efi":
        install_systemd_boot(efi_directory)
    elif efi_boot_loader == "sb-shim" and fw_type == "efi":
        install_secureboot(efi_directory)
    elif efi_boot_loader == "grub" or fw_type != "efi":
        install_grub(efi_directory, fw_type)
    else:
        libcalamares.utils.debug( "WARNING: the combination of "
            "boot-loader '{!s}' and firmware '{!s}' "
            "is not supported.".format(efi_boot_loader, fw_type) )


def run():
    """
    Starts procedure and passes 'fw_type' to other routine.

    :return:
    """

    fw_type = libcalamares.globalstorage.value("firmwareType")

    if (libcalamares.globalstorage.value("bootLoader") is None and fw_type != "efi"):
        libcalamares.utils.warning( "Non-EFI system, and no bootloader is set." )
        return None

    partitions = libcalamares.globalstorage.value("partitions")
    if fw_type == "efi":
        efi_system_partition = libcalamares.globalstorage.value("efiSystemPartition")
        esp_found = [ p for p in partitions if p["mountPoint"] == efi_system_partition ]
        if not esp_found:
            libcalamares.utils.warning( "EFI system, but nothing mounted on {!s}".format(efi_system_partition) )
            return None

    prepare_bootloader(fw_type)

    return None