<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
<refsect1>
<title>Kernel Command Line</title>
- <para>When run as system instance systemd parses a number of
- kernel command line arguments<footnote><para>If run inside a Linux
- container these arguments may be passed as command line arguments
- to systemd itself, next to any of the command line options listed
- in the Options section above. If run outside of Linux containers,
- these arguments are parsed from <filename>/proc/cmdline</filename>
- instead.</para></footnote>:</para>
+ <para>When run as the system instance systemd parses a number of options listed below. They can be
+ specified as kernel command line arguments<footnote><para>If run inside a Linux container these arguments
+ may be passed as command line arguments to systemd itself, next to any of the command line options listed
+ in the Options section above. If run outside of Linux containers, these arguments are parsed from
+ <filename>/proc/cmdline</filename> instead.</para></footnote>, or through the
+ <literal>SystemdOptions</literal> EFI variable (on EFI systems). The kernel command line has higher
+ priority. Following variables are understood:</para>
<variablelist class='kernel-commandline-options'>
<varlistentry>