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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
- "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="systemd-stub" conditional='ENABLE_BOOTLOADER'
<member><filename><replaceable>ESP</replaceable>/.../<replaceable>foo</replaceable>.efi.extra.d/*.addon.efi</filename></member>
<member><filename><replaceable>ESP</replaceable>/.../<replaceable>foo</replaceable>.efi.extra.d/*.cred</filename></member>
<member><filename><replaceable>ESP</replaceable>/.../<replaceable>foo</replaceable>.efi.extra.d/*.raw</filename></member>
+ <member><filename><replaceable>ESP</replaceable>/.../<replaceable>foo</replaceable>.efi.extra.d/*.sysext.raw</filename></member>
+ <member><filename><replaceable>ESP</replaceable>/.../<replaceable>foo</replaceable>.efi.extra.d/*.confext.raw</filename></member>
<member><filename><replaceable>ESP</replaceable>/loader/addons/*.addon.efi</filename></member>
<member><filename><replaceable>ESP</replaceable>/loader/credentials/*.cred</filename></member>
</simplelist></para>
<listitem><para>An <literal>.initrd</literal> section with the initrd.</para></listitem>
+ <listitem><para>A <literal>.ucode</literal> section with an initrd containing microcode, to be handed
+ to the kernel before any other initrd. This initrd must not be compressed.</para></listitem>
+
<listitem><para>A <literal>.splash</literal> section with an image (in the Windows
<filename>.BMP</filename> format) to show on screen before invoking the kernel.</para></listitem>
specific key.</para></listitem>
<listitem><para>A <literal>.pcrpkey</literal> section with a public key in the PEM format matching the
- signature data in the the <literal>.pcrsig</literal> section.</para></listitem>
+ signature data in the <literal>.pcrsig</literal> section.</para></listitem>
</itemizedlist>
<para>If UEFI SecureBoot is enabled and the <literal>.cmdline</literal> section is present in the executed
details on encrypted credentials. The generated <command>cpio</command> archive is measured into TPM
PCR 12 (if a TPM is present).</para></listitem>
- <listitem><para>Similarly, files <filename><replaceable>foo</replaceable>.efi.extra.d/*.raw</filename>
- are packed up in a <command>cpio</command> archive and placed in the <filename>/.extra/sysext/</filename>
- directory in the initrd file hierarchy. This is supposed to be used to pass additional system extension
- images to the initrd. See
+ <listitem><para>Similarly, files
+ <filename><replaceable>foo</replaceable>.efi.extra.d/*.sysext.raw</filename> are packed up in a
+ <command>cpio</command> archive and placed in the <filename>/.extra/sysext/</filename> directory in the
+ initrd file hierarchy. This is supposed to be used to pass additional system extension images to the
+ initrd. See
<citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
details on system extension images. The generated <command>cpio</command> archive containing these
system extension images is measured into TPM PCR 13 (if a TPM is present).</para></listitem>
+ <!-- Note: the actual suffix we look for for sysexts is just *.raw (not *.sysext.raw), for
+ compatibility reasons with old versions. But we want people to name their system extensions
+ properly, hence we document the *.sysext.raw suffix only. -->
+
+ <listitem><para>Similarly, files
+ <filename><replaceable>foo</replaceable>.efi.extra.d/*.confext.raw</filename> are packed up in a
+ <command>cpio</command> archive and placed in the <filename>/.extra/confext/</filename> directory in
+ the initrd file hierarchy. This is supposed to be used to pass additional configuration extension
+ images to the initrd. See
+ <citerefentry><refentrytitle>systemd-confext</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
+ details on configuration extension images. The generated <command>cpio</command> archive containing
+ these system extension images is measured into TPM PCR 12 (if a TPM is present).</para></listitem>
+
<listitem><para>Similarly, files
<filename><replaceable>foo</replaceable>.efi.extra.d/*.addon.efi</filename> are loaded and verified as
PE binaries, and a <literal>.cmdline</literal> section is parsed from them. Addons are supposed to be
configuration.</para>
<para>In case Secure Boot is enabled, these files will be validated using keys in UEFI DB, Shim's DB or
- Shim's MOK, and will be rejected otherwise. Additionally, if the both the addon and the UKI contain a a
+ Shim's MOK, and will be rejected otherwise. Additionally, if both the addon and the UKI contain a
<literal>.uname</literal> section, the addon will be rejected if they do not match exactly. It is
recommended to always add a <literal>.sbat</literal> section to all signed addons, so that they may be
revoked with a SBAT policy update, without requiring blocklisting via DBX/MOKX. The
core kernel, the embedded initrd and kernel command line (see above for a full list).</para>
<para>Also note that the Linux kernel will measure all initrds it receives into TPM PCR 9. This means
- every type of initrd will be measured two or three times: the initrd embedded in the kernel image will be
- measured to PCR 4, PCR 9 and PCR 11; the initrd synthesized from credentials will be measured to both PCR
- 9 and PCR 12; the initrd synthesized from system extensions will be measured to both PCR 4 and PCR
- 9. Let's summarize the OS resources and the PCRs they are measured to:</para>
+ every type of initrd will be measured two or three times: the initrds embedded in the kernel image will be
+ measured to PCR 4, PCR 9 and PCR 11; the initrd synthesized from credentials (and the one synthesized
+ from configuration extensions) will be measured to both PCR 9 and PCR 12; the initrd synthesized from
+ system extensions will be measured to both PCR 4 and PCR 9. Let's summarize the OS resources and the PCRs
+ they are measured to:</para>
<table>
<title>OS Resource PCR Summary</title>
<entry>4 + 9 + 11</entry>
</row>
+ <row>
+ <entry>Microcode initrd (embedded in unified PE binary)</entry>
+ <entry>4 + 9 + 11</entry>
+ </row>
+
<row>
<entry>Default kernel command line (embedded in unified PE binary)</entry>
<entry>4 + 11</entry>
<entry>System Extensions (synthesized initrd from companion files)</entry>
<entry>9 + 13</entry>
</row>
+
+ <row>
+ <entry>Configuration Extensions (synthesized initrd from companion files)</entry>
+ <entry>9 + 12</entry>
+ </row>
</tbody>
</tgroup>
</table>
<varlistentry>
<term><varname>StubPcrInitRDSysExts</varname></term>
- <listitem><para>The PCR register index the systemd extensions for the initrd, which are picked up
- from the file system the kernel image is located on. Formatted as decimal ASCII string (e.g.
+ <listitem><para>The PCR register index the system extensions for the initrd, which are picked up from
+ the file system the kernel image is located on. Formatted as decimal ASCII string (e.g.
<literal>13</literal>). This variable is set if a measurement was successfully completed, and remains
unset otherwise.</para>
<xi:include href="version-info.xml" xpointer="v252"/></listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><varname>StubPcrInitRDConfExts</varname></term>
+
+ <listitem><para>The PCR register index the configuration extensions for the initrd, which are picked
+ up from the file system the kernel image is located on. Formatted as decimal ASCII string (e.g.
+ <literal>12</literal>). This variable is set if a measurement was successfully completed, and remains
+ unset otherwise.</para>
+
+ <xi:include href="version-info.xml" xpointer="v255"/></listitem>
+ </varlistentry>
</variablelist>
<para>Note that some of the variables above may also be set by the boot loader. The stub will only set
</varlistentry>
<varlistentry>
- <term><filename>/.extra/sysext/*.raw</filename></term>
- <listitem><para>System extension image files (suffix <literal>.raw</literal>) that are placed next to
- the unified kernel image (as described above) are copied into the
+ <term><filename>/.extra/sysext/*.sysext.raw</filename></term>
+ <listitem><para>System extension image files (suffix <literal>.sysext.raw</literal>) that are placed
+ next to the unified kernel image (as described above) are copied into the
<filename>/.extra/sysext/</filename> directory in the initrd execution environment.</para>
<xi:include href="version-info.xml" xpointer="v252"/></listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>/.extra/confext/*.confext.raw</filename></term>
+ <listitem><para>Configuration extension image files (suffix <literal>.confext.raw</literal>) that are
+ placed next to the unified kernel image (as described above) are copied into the
+ <filename>/.extra/confext/</filename> directory in the initrd execution environment.</para>
+
+ <xi:include href="version-info.xml" xpointer="v255"/></listitem>
+ </varlistentry>
+
<varlistentry>
<term><filename>/.extra/tpm2-pcr-signature.json</filename></term>
<listitem><para>The TPM2 PCR signature JSON object included in the <literal>.pcrsig</literal> PE
<title>SMBIOS Type 11 Strings</title>
<para><command>systemd-stub</command> can be configured using SMBIOS Type 11 strings. Applicable strings
- consist of a name, followed by <literal>=</literal>, followed by the value.
+ consist of a name, followed by <literal>=</literal>, followed by the value. Unless
+ <command>systemd-stub</command> detects it is running inside a confidential computing environment,
<command>systemd-stub</command> will search the table for a string with a specific name, and if found,
use its value. The following strings are read:</para>
projects / thirdparty / systemd.git / blobdiff