man: document the systemd-random-seed rework
This commit is contained in:
Lennart Poettering
parent
c7bb4dfcf4
commit
39867bb9fb
|
|
@ -45,15 +45,15 @@
|
|||
<varlistentry>
|
||||
<term><option>--esp-path=</option></term>
|
||||
<listitem><para>Path to the EFI System Partition (ESP). If not specified, <filename>/efi/</filename>,
|
||||
<filename>/boot/</filename>, and <filename>/boot/efi</filename> are checked in turn. It is recommended to mount
|
||||
the ESP to <filename>/efi/</filename>, if possible.</para></listitem>
|
||||
<filename>/boot/</filename>, and <filename>/boot/efi/</filename> are checked in turn. It is
|
||||
recommended to mount the ESP to <filename>/efi/</filename>, if possible.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><option>--boot-path=</option></term>
|
||||
<listitem><para>Path to the Extended Boot Loader partition, as defined in the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>. If not
|
||||
specified, <filename>/boot/</filename> are checked. It is recommended to mount the Extended Boot
|
||||
specified, <filename>/boot/</filename> is checked. It is recommended to mount the Extended Boot
|
||||
Loader partition to <filename>/boot/</filename>, if possible.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
|
|
@ -124,6 +124,19 @@
|
|||
and the firmware's boot loader list.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><option>random-seed</option></term>
|
||||
|
||||
<listitem><para>Generates a random seed and stores it in the EFI System Partition, for use by the
|
||||
<command>systemd-boot</command> boot loader. Also, generates a random 'system token' and stores it
|
||||
persistently as an EFI variable, if one has not been set before. If the boot loader finds the random
|
||||
seed in the ESP and the system token in the EFI variable it will derive a random seed to pass to the
|
||||
OS and a new seed to store in the ESP from the combination of both. The random seed passed to the OS
|
||||
is credited to the kernel's entropy pool by the system manager during early boot, and permits
|
||||
userspace to boot up with an entropy pool fully initialized very early on. Also see
|
||||
<citerefentry><refentrytitle>systemd-boot-system-token.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><option>list</option></term>
|
||||
|
||||
|
|
@ -165,7 +178,8 @@
|
|||
<para>
|
||||
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||||
<ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>,
|
||||
<ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>
|
||||
<ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>,
|
||||
<citerefentry><refentrytitle>systemd-boot-system-token.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
</para>
|
||||
</refsect1>
|
||||
</refentry>
|
||||
|
|
|
|||
|
|
@ -153,6 +153,22 @@
|
|||
<listitem><para>Takes a boolean argument. Enable (the default) or disable
|
||||
the "Reboot into firmware" entry.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term>random-seed-mode</term>
|
||||
|
||||
<listitem><para>Takes one of <literal>off</literal>, <literal>with-system-token</literal> and
|
||||
<literal>always</literal>. If <literal>off</literal> no random seed data is read off the ESP, nor
|
||||
passed to the OS. If <literal>with-system-token</literal> (the default)
|
||||
<command>systemd-boot</command> will read a random seed from the ESP (from the file
|
||||
<filename>/loader/random-seed</filename>) only if the <varname>LoaderSystemToken</varname> EFI
|
||||
variable is set, and then derive the random seed to pass to the OS from the combination. If
|
||||
<literal>always</literal> the boot loader will do so even if <varname>LoaderSystemToken</varname> is
|
||||
not set. This mode is useful in environments where protection against OS image reuse is not a
|
||||
concern, and the random seed shall be used even with no further setup in place. User <command>bootctl
|
||||
random-seed</command> to initialize both the random seed file in the ESP and the system token EFI
|
||||
variable.</para></listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
|
|
|
|||
|
|
@ -655,6 +655,7 @@ manpages = [
|
|||
['systemd-bless-boot-generator', '8', [], 'ENABLE_EFI'],
|
||||
['systemd-bless-boot.service', '8', [], 'ENABLE_EFI'],
|
||||
['systemd-boot-check-no-failures.service', '8', [], ''],
|
||||
['systemd-boot-system-token.service', '8', [], 'ENABLE_EFI'],
|
||||
['systemd-boot', '7', ['sd-boot'], 'ENABLE_EFI'],
|
||||
['systemd-cat', '1', [], ''],
|
||||
['systemd-cgls', '1', [], ''],
|
||||
|
|
|
|||
|
|
@ -0,0 +1,76 @@
|
|||
<?xml version='1.0'?> <!--*-nxml-*-->
|
||||
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
||||
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
||||
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
|
||||
|
||||
<refentry id="systemd-boot-system-token.service" conditional='ENABLE_EFI'
|
||||
xmlns:xi="http://www.w3.org/2001/XInclude">
|
||||
|
||||
<refentryinfo>
|
||||
<title>systemd-boot-system-token.service</title>
|
||||
<productname>systemd</productname>
|
||||
</refentryinfo>
|
||||
|
||||
<refmeta>
|
||||
<refentrytitle>systemd-boot-system-token.service</refentrytitle>
|
||||
<manvolnum>8</manvolnum>
|
||||
</refmeta>
|
||||
|
||||
<refnamediv>
|
||||
<refname>systemd-boot-system-token.service</refname>
|
||||
<refpurpose>Generate an initial boot loader system token and random seed</refpurpose>
|
||||
</refnamediv>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<para><filename>systemd-boot-system-token.service</filename></para>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para><filename>systemd-boot-system-token.service</filename> is a system service that automatically
|
||||
generates a 'system token' to store in an EFI variable in the system's NVRAM and a random seed to store
|
||||
on the EFI System Partition ESP on disk. The boot loader may then combine these two randomized data
|
||||
fields by cryptographic hashing, and pass it to the OS it boots as initialization seed for its entropy
|
||||
pool. The random seed stored in the ESP is refreshed on each reboot ensuring that multiple subsequent
|
||||
boots will boot with different seeds. The 'system token' is generated randomly once, and then
|
||||
persistently stored in the system's EFI variable storage.</para>
|
||||
|
||||
<para>The <filename>systemd-boot-system-token.service</filename> unit invokes the <command>bootctl
|
||||
random-seed</command> command, which updates the random seed in the ESP, and initializes the 'system
|
||||
token' if it's not initialized yet. The service is conditionalized so that it is run only when all of the
|
||||
below apply:</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>A boot loader is used that implements the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink> (which defines the 'system
|
||||
token' concept).</para></listitem>
|
||||
|
||||
<listitem><para>Either a 'system token' was not set yet, or the boot loader has not passed the OS a
|
||||
random seed yet (and thus most likely has been missing the random seed file in the
|
||||
ESP).</para></listitem>
|
||||
|
||||
<listitem><para>The system is not running in a VM environment. This case is explicitly excluded since
|
||||
on VM environments the ESP backing storage and EFI variable storage is typically not physically
|
||||
separated and hence booting the same OS image in multiple instances would replicate both, thus reusing
|
||||
the same random seed and 'system token' among all instances, which defeats its purpose. Note that it's
|
||||
still possible to use boot loader random seed provisioning in this mode, but the automatic logic
|
||||
implemented by this service has no effect then, and the user instead has to manually invoke the
|
||||
<command>bootctl random-seed</command> acknowledging these restrictions.</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para>For further details see
|
||||
<citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, regarding
|
||||
the command this service invokes.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
<para>
|
||||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
</refentry>
|
||||
|
|
@ -28,13 +28,14 @@
|
|||
manager. It provides a graphical menu to select the entry to boot and an editor for the kernel command
|
||||
line. <command>systemd-boot</command> supports systems with UEFI firmware only.</para>
|
||||
|
||||
<para>systemd-boot loads boot entry information from the EFI system partition (ESP), usually mounted at
|
||||
<filename>/efi/</filename>, <filename>/boot/</filename>, or <filename>/boot/efi/</filename> during OS
|
||||
runtime, as well as from the Extended Boot Loader partition if it exists (usually mounted to
|
||||
<filename>/boot/</filename>). Configuration file fragments, kernels, initrds and other EFI images to boot
|
||||
generally need to reside on the ESP or the Extended Boot Loader partition. Linux kernels must be built
|
||||
with <option>CONFIG_EFI_STUB</option> to be able to be directly executed as an EFI image. During boot
|
||||
systemd-boot automatically assembles a list of boot entries from the following sources:</para>
|
||||
<para><command>systemd-boot</command> loads boot entry information from the EFI system partition (ESP),
|
||||
usually mounted at <filename>/efi/</filename>, <filename>/boot/</filename>, or
|
||||
<filename>/boot/efi/</filename> during OS runtime, as well as from the Extended Boot Loader partition if
|
||||
it exists (usually mounted to <filename>/boot/</filename>). Configuration file fragments, kernels,
|
||||
initrds and other EFI images to boot generally need to reside on the ESP or the Extended Boot Loader
|
||||
partition. Linux kernels must be built with <option>CONFIG_EFI_STUB</option> to be able to be directly
|
||||
executed as an EFI image. During boot <command>systemd-boot</command> automatically assembles a list of
|
||||
boot entries from the following sources:</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>Boot entries defined with <ulink
|
||||
|
|
@ -57,17 +58,50 @@
|
|||
<listitem><para>A reboot into the UEFI firmware setup option, if supported by the firmware</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para><citerefentry><refentrytitle>kernel-install</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
may be used to copy kernel images onto the ESP or the Extended Boot Loader Partition and to generate
|
||||
description files compliant with the Boot Loader
|
||||
Specification. <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
<para><command>systemd-boot</command> supports the following features:</para>
|
||||
|
||||
<itemizedlist>
|
||||
<listitem><para>Basic boot manager configuration changes (such as timeout
|
||||
configuration, default boot entry selection, …) may be made directly from the boot loader UI at
|
||||
boot-time, as well as during system runtime with EFI variables.</para></listitem>
|
||||
|
||||
<listitem><para>The boot manager integrates with the <command>systemctl</command> command to implement
|
||||
features such as <command>systemctl reboot --boot-loader-entry=…</command> (for rebooting into a
|
||||
specific boot menu entry, i.e. "reboot into Windows") and <command>systemctl reboot
|
||||
--boot-loader-menu=…</command> (for rebooting into the boot loader menu), by implementing the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>. See
|
||||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
|
||||
details.</para></listitem>
|
||||
|
||||
<listitem><para>An EFI variable set by the boot loader informs the OS about the ESP partition used
|
||||
during boot. This is then used to automatically mount the correct ESP partition to
|
||||
<filename>/efi/</filename> or <filename>/boot/</filename> during OS runtime. See
|
||||
<citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
for details.</para></listitem>
|
||||
|
||||
<listitem><para>The boot manager provides information about the boot time spent in UEFI firmware using
|
||||
the <ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>. This
|
||||
information can be displayed using
|
||||
<citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||||
</para></listitem>
|
||||
|
||||
<listitem><para>The boot manager implements boot counting and automatic fallback to older, working boot
|
||||
entries on failure. See <ulink url="https://systemd.io/AUTOMATIC_BOOT_ASSESSMENT">Automatic Boot
|
||||
Assessment</ulink>.</para></listitem>
|
||||
|
||||
<listitem><para>The boot manager optionally reads a random seed from the ESP partition, combines it
|
||||
with a 'system token' stored in a persistant EFI variable and derives a random seed to use by the OS as
|
||||
entropy pool initializaton, providing a full entropy pool during early boot.</para></listitem>
|
||||
</itemizedlist>
|
||||
|
||||
<para><citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
may be used from a running system to locate the ESP and the Extended Boot Loader Partition, list
|
||||
available entries, and install <command>systemd-boot</command> itself.</para>
|
||||
|
||||
<para>systemd-boot will provide information about the time spent in UEFI firmware using the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>. This information can be displayed
|
||||
using <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
|
||||
</para>
|
||||
<para><citerefentry><refentrytitle>kernel-install</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||||
may be used to copy kernel images onto the ESP or the Extended Boot Loader Partition and to generate
|
||||
description files compliant with the Boot Loader
|
||||
Specification.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -238,7 +272,9 @@
|
|||
Loader Specification</ulink> are read from <filename>/loader/entries/</filename> on the ESP and the
|
||||
Extended Boot Loader partition. Unified kernel boot entries following the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink> are read from
|
||||
<filename>/EFI/Linux/</filename> on the ESP and the Extended Boot Loader partition.</para>
|
||||
<filename>/EFI/Linux/</filename> on the ESP and the Extended Boot Loader partition. Optionally, a random
|
||||
seed for early boot entropy pool provisioning is stored in <filename>/loader/random-seed</filename> in
|
||||
the ESP.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -346,10 +382,39 @@
|
|||
|
||||
<listitem><para>Information about the time spent in various parts of the boot loader. Set by the boot
|
||||
loader. Use <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
to view this data. These variables are defined by the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>.</para></listitem>
|
||||
to view this data. </para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>LoaderRandomSeed</varname></term>
|
||||
|
||||
<listitem><para>A binary random seed <command>systemd-boot</command> may optionally pass to the
|
||||
OS. This is a volatile EFI variable that is hashed at boot from the combination of a random seed
|
||||
stored in the ESP (in <filename>/loader/random-seed</filename>) and a "system token" persistently
|
||||
stored in the EFI variable <varname>LoaderSystemToken</varname> (see below). During early OS boot the
|
||||
system manager reads this variable and passes it to the OS kernel's random pool, crediting the full
|
||||
entropy it contains. This is an efficient way to ensure the system starts up with a fully initialized
|
||||
kernel random pool — as early as the initial RAM disk phase. <command>systemd-boot</command> reads
|
||||
the random seed from the ESP, combines it with the "system token", and both derives a new random seed
|
||||
to update in-place the seed stored in the ESP, and the random seed to pass to the OS from it via
|
||||
SHA256 hashing in counter mode. This ensures that different physical systems that boot the same
|
||||
"golden" OS image — i.e. containing the same random seed file in the ESP — will still pass a
|
||||
different random seed to the OS. It is made sure the random seed stored in the ESP is fully
|
||||
overwritten before the OS is booted, to ensure different random seed data is used between subsequent
|
||||
boots.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>LoaderSystemToken</varname></term>
|
||||
|
||||
<listitem><para>A binary random data field, that is used for generating the random see to pass to the
|
||||
OS (see above). Note that this random data is generally only generated once, during OS installation,
|
||||
and is then never updated again.</para></listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
|
||||
<para>Many of these variables are defined by the <ulink
|
||||
url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -413,6 +478,7 @@
|
|||
<citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>loader.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-bless-boot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-boot-system-token.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>kernel-install</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||||
<ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>,
|
||||
<ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>
|
||||
|
|
|
|||
|
|
@ -29,21 +29,60 @@
|
|||
<refsect1>
|
||||
<title>Description</title>
|
||||
|
||||
<para><filename>systemd-random-seed.service</filename> is a
|
||||
service that restores the random seed of the system at early boot
|
||||
and saves it at shutdown. See
|
||||
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>
|
||||
for details. Saving/restoring the random seed across boots
|
||||
increases the amount of available entropy early at boot. On disk
|
||||
the random seed is stored in
|
||||
<filename>/var/lib/systemd/random-seed</filename>.</para>
|
||||
<para><filename>systemd-random-seed.service</filename> is a service that loads an on-disk random seed
|
||||
into the kernel entropy pool during boot and saves it at shutdown. See
|
||||
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for
|
||||
details. By default, no entropy is credited when the random seed is written into the kernel entropy pool,
|
||||
but this may be changed with <varname>$SYSTEMD_RANDOM_SEED_CREDIT</varname>, see below. On disk the random
|
||||
seed is stored in <filename>/var/lib/systemd/random-seed</filename>.</para>
|
||||
|
||||
<para>Note that this service runs relatively late during the early boot phase, i.e. generally after the
|
||||
initial RAM disk (initrd) completed its work, and the <filename>/var/</filename> file system has been
|
||||
mounted writable. Many system services require entropy much earlier than this — this service is hence of
|
||||
limited use for complex system. It is recommended to use a boot loader that can pass an initial random
|
||||
seed to the kernel to ensure that entropy is available from earliest boot on, for example
|
||||
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>, with
|
||||
its <command>bootctl random-seed</command> functionality.</para>
|
||||
|
||||
<para>When loading the random seed from disk its file is immediately updated with a new seed retrieved
|
||||
from the kernel, in order to ensure no two boots operate with the same random seed. This new seed is
|
||||
retrieved synchronously from the kernel, which means the service will not complete start-up until the
|
||||
random pool is fully initialized. On entropy-starved systems this may take a while. This functionality is
|
||||
intended to be used as synchronization point for ordering services that require an initialized entropy
|
||||
pool to function securely (i.e. services that access <filename>/dev/urandom</filename> without any
|
||||
further precautions).</para>
|
||||
|
||||
<para>Care should be taken when creating OS images that are replicated to multiple systems: if the random
|
||||
seed file is included unmodified each system will initialize its entropy pool with the same data, and
|
||||
thus — if otherwise entropy-starved — generate the same or at least guessable random seed streams. As a
|
||||
safety precaution crediting entropy is thus disabled by default. It is recommended to remove the random
|
||||
seed from OS images intended for replication on multiple systems, in which case it is safe to enable
|
||||
entropy crediting, see below.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>Environment</title>
|
||||
|
||||
<variablelist class='environment-variables'>
|
||||
<varlistentry>
|
||||
<term><varname>$SYSTEMD_RANDOM_SEED_CREDIT</varname></term>
|
||||
<listitem><para>By default, <filename>systemd-random-seed.service</filename> does not credit any
|
||||
entropy when loading the random seed. With this option this behaviour may be changed: it either takes
|
||||
a boolean parameter or the special string <literal>force</literal>. Defaults to false, in which case
|
||||
no entropy is credited. If true, entropy is credited if the random seed file and system state pass
|
||||
various superficial concisistency checks. If set to <literal>force</literal> entropy is credited,
|
||||
regardless of these checks, as long as the random seed file exists.</para></listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
<title>See Also</title>
|
||||
<para>
|
||||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>
|
||||
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||||
<citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>4</manvolnum></citerefentry>
|
||||
</para>
|
||||
</refsect1>
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue