This reverts commit 5e8ff010a1.
This broke all the URLs, we can't have that. (And actually, we probably don't
_want_ to make the change either. It's nicer to have all the pages in one
directory, so one doesn't have to figure out to which collection the page
belongs.)
In 53c26db4da the meaning of $BOOT was
redefined. I think that's quite problematic, since the concept is
implemented in code and interface of bootctl. Thus, I think we should
stick to the original definition, which is: "where to *place* boot menu
entries" (as opposed to "where to *read* boot menu entries from").
The aforementioned change was done to address two things afaiu:
1. it focussed on a $BOOT as the single place to put boot entries in,
instead of mentioning that both ESP and $BOOT are expected to be
the source
2. it mentioned the /loader/ dir (as location for boot loader resources)
itself as part of the spec, which however only really makes sense in
the ESP. /loader/entries/ otoh makes sense in either the ESP or
$BOOT.
With this rework I try to address these two issues differently:
1. I intend to make clear the $BOOT is the "primary" place to put stuff
in, and is what should be mounted to /boot/.
2. The ESP (if different from $BOOT) is listed as "secondary" source to
read from, and is what should be mounted to /efi/. NB we now make the
distinction between "where to put" (which is single partition) and
"where to read from".
3. This drops any reference of the /loader/ dir witout the /entries/
suffix. Only the full /loader/entries/ dir (and its companion file
/loader/entries.srel) are now mentioned. Thus isolated /loader/
directory hence becomes irrelevant in the spec, and the fact that
sd-boot maintains some files there (and only in the ESP) is kept out
of the spec, because it is irrelevant to other boot loaders.
4. It puts back the suggestion to mount $BOOT to /boot/ and the ESP to
/efi/ (and suggests adding a symlink or bind mount if both are the
same partition). Why? Because the dirs are semantically unrelated:
it's OK and common to have and ESP but no $BOOT, hence putting ESP
inside of a useless, non-existing "ghost" dir /boot/ makes little
sense. More importantly though, because these partitions are
typically backed by VFAT we want to maintain them as an autofs, with
a short idle delay, so that the file systems are unmounted (and thus
fully clean) at almost all times. This doesn't work if they are
nested within each other, as the establishment of the inner autofs
would pin the outer one, making the excercise useless. Now I don't
think the spec should mention autofs (since that is an implementation
detail), but it should arrange things so that this specific, very
efficient, safe and robust implementation can be implemented.
The net result should be easy from an OS perspective:
1. *Put* boot loader entries in /boot/, always.
2. *Read* boot loader entries from both /boot/ and /efi/ -- if these are distinct.
3. The only things we define in the spec are /loader/entries/*.conf and
/EFI/Linux/*.efi in these two partitions (well, and the companion
file /loader/entries.srel
4. /efi/ and /boot/ because not nested can be autofs.
5. bootctl code and interface (in particular --esp-path= and
--boot-path=) match the spec again. `bootctl -x` and `bootctl -p`
will now print the path to $BOOT and ESP again, matching the concepts
in the spec again.
From the sd-boot perspective things are equally easy:
1. Read boot enrties from ESP and XBOOTLDR.
2. Maintain boot loader config/other resources in ESP only.
And that's it.
Fixes: #24247
The boot-counting file-renaming entry-sorting part that the boot
loader implements is moved to the main document. The second document
describes a specific implementation that is provided through systemd
units.
The sorting algorithm is extended to say that bad entries should
be sorted later.
I also added a note that bad entries should be available for booting.
For some reason, the second document said that it applies only to EFI systems.
AFAIK there are no implementations for non-EFI, but the specification should
work just fine, if somebody were to implement it. So that part is dropped.
Fixes#23345.
Sadly, bootctl doesn't implement sorting of boot entries with counting :((((
But I'm leaving that for another PR.
The text used was originally written for everything being on the ESP. It was
later generalized for support XBOOTLDR, and "$BOOT" was introduced to mean
something like "XBOOTLDR if present, the ESP otherwise", and most of the text
was changed to talk about $BOOT. Sadly, this doesn't work, because the two
partitions are not interchangeable. sd-boot loads entries from both partitions,
and its configuration, random-seed, etc. only from the ESP.
The terms are redefined: $BOOT now means either the ESP or the "boot partition"
playing the same role on MBR systems, and $XBOOTLDR is XBOOTLDR.
Like various previous commits, this makes the specification describe our
current implementation.
Also, the let's just accept the common practice of using /boot and /boot/efi.
Since both partitions need to be read to gather configuration, it isn't a
problem that one is mounted underneath the other one. I think having /boot and
/efi is OK, but not better in any measureable way, so let's stop trying to push
people towards this setup.
A note that XBOOTLDR must be on the same disk as ESP is added.
We said "`$BOOT/loader/` is the directory containing all files needed
for Type #1 entries" which is blatantly wrong. And also saying that we
define two directories, /loader and /loader/entries, but only ever defining
the second one was not very consistent.
Instead, let's say that /loader/ is for "boot loader configuration", and
/loader/entries has the snippets. A new section about /<entry-token>/<version>/
is added. This is described as the "recommended layout for additional files".
Also, we said that ID= should be used in the file name, but in fact it
wasn't in the example that was given, and afaik, nobody ever did that. So
this part is reduced to say "kernel version (as returned by `uname -r`,
including the OS identifier)". AFAIK, all distros include some form of
OS identifier in the version, so this should be good enough.
Since we now don't depend on autodetection (e.g. with entry-token and layout
configured), the installed doesn't need to always create /loader/entries and
things will still work. So don't say that the installer needs to create it.
Part of the discussion is moved to the Discussion section.
Overall, this brings the specification more in line with actual practice.
I tried not to introduce any semantic changes, but to reorder the whole
text to be more usable as a reference specification: more sections are
created and the discussion and justifications are moved to the end.
Also, "BIOS" is changed to "firmware" in various places, and other parts
of the text that made sense when this was originally written are now dated
are adjusted. I separated and extended the examples a bit.
The abstract at the top ("TL;DR: Currently there’s no common boot scheme…")
is dropped. It didn't seem to fit anywhere.
This new file is supposed to address conflicts with Fedora/Grub's
frankenbootloaderspec implementation, that squatted the /loader/entries/
dir, but place incompatible files in them (that do variable expansion?).
A simple text file /loader/entries.srel shall indicate which spec is
implemented. If it contains the string "type1\n" then the
/loader/entries/ directory implements our standard spec, otherwise
something else.
This allows snippet generators to explicitly order entries: any string
can be set as an entry's "sort key". If set, sd-boot will use it to sort
entries on display.
New logic is hence (ignore the boot counting logic)
sort-key is set → primary sort key: sort-key (lexicographically increasing order)
→ secondary sort key: machine-id (also increasing order)
→ tertiary sort key: version (lexicographically decreasing order!)
sort-key is not set → primary sort key: entry filename (aka id), lexicographically increasing order)
With this scheme we can order OSes by their names from A-Z but then put
within the same OS still the newest version first. This should clean up
the order to match expectations more.
Based on discussions here:
https://github.com/systemd/systemd/pull/22391#issuecomment-1040092633
I have no idea if this is going to cause rendering problems, and it is fairly
hard to check. So let's just merge this, and if it github markdown processor
doesn't like it, revert.
I think it makes sense to keep the "The" in place for the actual page's
title, but let's drop it from the categorization header, to make it
easier to find stuff, as the "The" isn't helpful to that.
In particular as we sometimes do it this and sometimes the other way so
far, hence let's stick to one common rule.
Device tree overlays are a convenient way to patch device trees, e.g.,
add new devices to a device tree or enable/disable devices. This is
useful for non-discoverable but configurable hardware. Device tree
overlays are commonly used for displays on the Raspberry Pi or for
describing the content of FPGA bitstreams.
Add the devicetree-overlay key to boot loader specification entries to
allow boot loaders to apply overlays.
See #13537
It turns out Jekyll (the engine behind GitHub Pages) requires that pages
include a "Front Matter" snippet of YAML at the top for proper rendering.
Omitting it will still render the pages, but including it opens up new
possibilities, such as using a {% for %} loop to generate index.md instead of
requiring a separate script.
I'm hoping this will also fix the issue with some of the pages (notably
CODE_OF_CONDUCT.html) not being available under systemd.io
Tested locally by rendering the website with Jekyll. Before this change, the
*.md files were kept unchanged (so not sure how that even works?!), after this
commit, proper *.html files were generated from it.
A couple of changes:
1. Clearly name the drop-in entry files "Type #1", and the unified
kernel images "Type #2", and be clearer that the latter is specific
to UEFI.
2. Suffix all directory paths with a trailing "/" to clarify that these
are directories. Also, enclose them all in ``.
3. Add introductory paragraph that explains that there is Type #1 and
Type #2 and what they are about.
4. Explain that Type #2 is about signed UEFI SecureBoot.
5. Don't claim that $BOOT/loader/ contains really all files defined by
the spec, because that's not true, Type #2 images are not located there
after all.
Fixes: #10399
The docs/ directory is special in GitHub, since it can be used to serve GitHub
Pages from, so there's a benefit to switching to it in order to expose it
directly as a website.
Updated references to it from the documentations themselves, from the
CONTRIBUTING.md file and from Meson build files.
