This commit adds support for loading, measuring and handling a ".ucode"
UKI section. This section is functionally an initrd, intended for
microcode updates. As such it will always be passed to the kernel first.
This does what we do for system extension also for configuration
extension.
This is complicated by the fact that we previously looked for
<uki-binary>.d/*.raw for system extensions. We want to measure sysexts
and confexts to different PCRs (13 vs. 12) hence we must distinguish
them, but *.raw would match both kinds.
This commit solves this via the following mechanism: we'll load confexts
from *.confext.raw and sysexts from *.raw but will then enclude
*.confext.raw from the latter. This preserves compatibility but allows
us to somewhat reasonable distinguish both types of images.
The documentation is updated not going into this detail though, and
instead now claims that sysexts shall be *.sysext.raw and confexts
*.confext.raw even though we actually are more lenient than this. This
is simply to push people towards using the longer, more descriptive
suffixes.
I added an XML comment (<!-- … -->) about this to the docs, so that
whenever somebody notices the difference between code and docs
understands why and leaves it that way.
With <para><filename>…</filename></para>, we get a separate "paragraph" for
each line, i.e. entries separated by empty lines. This uses up a lot of space
and was only done because docbook makes it hard to insert a newline. In some
other places, <literallayout> was used, but then we cannot indent the source
text (because the whitespace would end up in the final page). We can get the
desired result with <simplelist>.
With <simplelist> the items are indented in roff output, but not in html
output. In some places this looks better then no indentation, and in others it
would probably be better to have no indent. But this is a minor issue and we
cannot control that.
(I didn't convert all spots. There's a bunch of other man pages which have two
lines, e.g. an executable and service file, and it doesn't matter there so
much.)
Let's put the section name at the beginning of each sentence. This way we
can avoid awkward constructs like "kernel is looked for in the .linux section".
Also, since the paragraph above says that this is a list of "PE sections", we
can just say "section". In other places, it is often useful to say "PE section"
to avoid ambiguity.
Also fix the off-by-one in the count of sections.
If `foo+3-0.efi` is booted when there are some files in `foo.efi.extra.d`,
those files are ignored. But after the boot is blessed and the system rebooted,
those file are taken into account, and the boot is different from first
boot. This behavior is a bit puzzling.
Instead we now ignore the counter and always look for the extra files in
`foo.efi.extra.d` and always boot the same way.
This fixes the PE section documentation in the systemd-stub man page:
for some reason .uname was listed twice, and .sbat was still missing.
Address that.
Also, let's reorder things to to match the "canonical" ordering we also
use for measurement in sd-stub. The order makes sense and there's really
no reason to depart from that here.
Minor other tweaks.
Reverts b6f2e68602, among other things
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
Files placed in /EFI/Linux/UKI.efi.extra.d/ and /loader/addons/ are
opened and verified using the LoadImage protocol, and will thus get
verified via shim/firmware.
If they are valid signed PE files, the .cmdline section will be
extracted and appended. If there are multiple addons in each directory,
they will be parsed in alphanumerical order.
Optionally the .uname sections are also matched if present, so
that they can be used to filter out addons as well if needed, and only
addons that correspond exactly to the UKI being loaded are used.
It is recommended to also always add a .sbat section to addons, so
that they can be mass-revoked with just a policy update.
The files must have a .addon.efi suffix.
Files in the per-UKI directory are parsed, sorted, measured and
appended first. Then, files in the generic directory are processed.
PCR1, where SMBIOS strings are measured, is filled with data that is not
under the control of the machine owner. Measure cmdline extensions in
PCR12 too, where we measure other optional addons that are loaded by
sd-stub.
This drops all mentions of gnu-efi and its manual build machinery. A
future commit will bring bootloader builds back. A new bootloader meson
option is now used to control whether to build sd-boot and its userspace
tooling.
Let's read more kernel command line arguments from SMBIOS OEM string
io.systemd.stub.kernel-cmdline-extra. This allows adding debug kernel
command line arguments when booting in qemy without having to modify
the UKI.
