<refsect1>
<title>Description</title>
- <para>The kernel, the initial RAM disk (initrd) and
- basic userspace functionality may be configured at boot via
- kernel command line arguments.</para>
+ <para>The kernel, the initial RAM disk (initrd) and basic userspace functionality may be configured at
+ boot via kernel command line arguments. In addition, various systemd tools look at the EFI variable
+ <literal>SystemdOptions</literal> (if available). Both sources are combined, but the kernel command line
+ has higher priority. Please note that <emphasis>the EFI variable is only used by systemd tools, and is
+ ignored by the kernel and other user space tools</emphasis>, so it is not a replacement for the kernel
+ command line.</para>
<para>For command line parameters understood by the kernel, please
see
<term><varname>systemd.confirm_spawn</varname></term>
<term><varname>systemd.service_watchdogs</varname></term>
<term><varname>systemd.show_status</varname></term>
+ <term><varname>systemd.status_unit_format=</varname></term>
<term><varname>systemd.log_target=</varname></term>
<term><varname>systemd.log_level=</varname></term>
<term><varname>systemd.log_location=</varname></term>
<term><varname>systemd.early_core_pattern=</varname></term>
<listitem>
<para>During early boot, the generation of core dump files is disabled until a core dump handler (if any)
- takes over. This parameter allows to specifies an absolute path where core dump files should be stored until
+ takes over. This parameter allows specifying an absolute path where core dump files should be stored until
a handler is installed. The path should be absolute and may contain specifiers, see
- <citerefentry><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.</para>
+ <citerefentry project='man-pages'><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.</para>
</listitem>
</varlistentry>
<term><varname>rd.udev.exec_delay=</varname></term>
<term><varname>udev.event_timeout=</varname></term>
<term><varname>rd.udev.event_timeout=</varname></term>
+ <term><varname>udev.timeout_signal=</varname></term>
+ <term><varname>rd.udev.timeout_signal=</varname></term>
+ <term><varname>udev.blockdev_read_only</varname></term>
+ <term><varname>rd.udev.blockdev_read_only</varname></term>
<term><varname>net.ifnames=</varname></term>
<term><varname>net.naming-scheme=</varname></term>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>systemd.cpu_affinity=</varname></term>
+
+ <listitem>
+ <para>Overrides the CPU affinity mask for the service manager and the default for all child
+ processes it forks. This takes precedence over <varname>CPUAffinity=</varname>, see
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>modules_load=</varname></term>
<term><varname>rd.modules_load=</varname></term>
<listitem><para>Takes a boolean argument, defaults to on. If off,
<citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- will not query the user for basic system settings, even if the system boots up for the first time and the
- relevant settings are not initialized yet.</para></listitem>
+ will not query the user for basic system settings, even if the system boots up for the first time and
+ the relevant settings are not initialized yet. Not to be confused with
+ <varname>systemd.condition-first-boot=</varname> (see below), which overrides the result of the
+ <varname>ConditionFirstBoot=</varname> unit file condition, and thus controls more than just
+ <filename>systemd-firstboot.service</filename> behaviour.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.condition-needs-update=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If specified, overrides the result of
+ <varname>ConditionNeedsUpdate=</varname> unit condition checks. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.condition-first-boot=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If specified, overrides the result of
+ <varname>ConditionFirstBoot=</varname> unit condition checks. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details. Not to be confused with <varname>systemd.firstboot=</varname> which only controls behaviour
+ of the <filename>systemd-firstboot.service</filename> system service but has no effect on the
+ condition check (see above).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.clock-usec=</varname></term>
+
+ <listitem><para>Takes a decimal, numeric timestamp in µs since January 1st 1970, 00:00am, to set the
+ system clock to. The system time is set to the specified timestamp early during boot. It is not
+ propagated to the hardware clock (RTC).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.random-seed=</varname></term>
+
+ <listitem><para>Takes a base64 encoded random seed value to credit with full entropy to the kernel's
+ random pool during early service manager initialization. This option is useful in testing
+ environments where delays due to random pool initialization in entropy starved virtual machines shall
+ be avoided.</para>
+
+ <para>Note that if this option is used the seed is accessible to unprivileged programs from
+ <filename>/proc/cmdline</filename>. This option is hence a security risk when used outside of test
+ systems, since the (possibly) only seed used for initialization of the kernel's entropy pool might be
+ easily acquired by unprivileged programs.</para>
+
+ <para>It is recommended to pass 512 bytes of randomized data (as that matches the Linux kernel pool
+ size), which may be generated with a command like the following:</para>
+
+ <programlisting>dd if=/dev/urandom bs=512 count=1 status=none | base64 -w 0</programlisting>
+
+ <para>Again: do not use this option outside of testing environments, it's a security risk elsewhere,
+ as secret key material derived from the entropy pool can possibly be reconstructed by unprivileged
+ programs.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.hostname=</varname></term>
+
+ <listitem><para>Accepts a hostname to set during early boot. If specified takes precedence over what
+ is set in <filename>/etc/hostname</filename>. Note that this does not bar later runtime changes to
+ the hostname, it simply controls the initial hostname set during early boot.</para></listitem>
</varlistentry>
</variablelist>
<citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
projects / thirdparty / systemd.git / blobdiff