In many places we spelled out the phrase behind "initrd" in full, but this
isn't terribly useful. In fact, no "RAM disk" is used, so emphasizing this
is just confusing to the reader. Let's just say "initrd" everywhere, people
understand what this refers to, and that it's in fact an initramfs image.
Also, s/i.e./e.g./ where appropriate.
Also, don't say "in RAM", when in fact it's virtual memory, whose pages
may or may not be loaded in page frames in RAM, and we have no control over
this.
Also, add <filename></filename> and other minor cleanups.
It's pretty hard to write tests without this. I started out by adding separate
variables for each of the files we read, but there's a bunch, and in practice
it's good enough to just override the directory.
Variables read by kernel-install and those exported by it were described
without any clear separation. So in particular it was pretty hard to answer
a question like "what variables can be set in install.conf". The in- and
out-variables are now split into two separate subsections.
In --help output, change "$0" → "kernel-install". We generally don't include
the full path in --help output, and let's not do this here either.
kernel-install is now in build/ directly, not in the subdirectory.
Change f887eab1da conditionalized the
building of ther kenel-install man page in the generated meson output,
instead of the source in the XML markup. Thus, whenever the rules file
is updated the conditionalization is lost. Correct that.
Follow-up for: f887eab1da
This drops documentation of KERNEL_INSTALL_MACHINE_ID as machine-info
field (though we'll still read it for compat).
This updates the kernel-install man page to always say "ENTRY-TOKEN"
instead of "MACHINE-ID" where appropriate, to clear the confusion up
between the two.
This also tries to fix how we denote env vars (always prefix with $ and
without = suffix), and other vars (without $ but with = suffix)
Other fixes.
The general approach of kernel-install was that each plugin would drop in some
files into the entry directory. But this doesn't scale well, because if we have
multiple initrd generators, or multiple initrds, each generator would need to
recreate the logic to put the generated files in the right place.
Also, effective cleanup is impossible if anything goes wrong on the way, so we
could end up with unused files in $BOOT.
So let's invert the process: plugins drop files into $KERNEL_INSTALL_STAGING_AREA,
and at the end 90-loaderentry.install DTRT with those files.
This allow new plugins like 50-mkosi-initrd.install to be significantly simpler.
The idea is that when not set, we do whatever we did in the past. But
with a new setting of initrd_generator=mkosi-initrd, mkosi-initrd will
generate an initrd.
341890de86 made "bootctl install" create
ESP\MID, in preparation of cf73f65089 that
followed it and created 00-entry-directory.install to make ESP\MID\KVER
if ESP\MID existed ‒ this meant that "bootctl install" followed by
"kernel-install $(uname -r) /boot/vml*$(uname -r) /boot/ini*$(uname -r)"
actually installed the kernel correctly.
Later, 31e57550b5 reverted the first
commit, meaning, that now running those two commands first installs
sd-boot, but then does nothing. Everything appears to work right,
nothing errors out, but no changes are actually done. To the untrained
eye (all of them), even running with -v appears to work:
all the hooks are run, as is depmod, but, again, nothing happens.
This is horrible. Nothing in either manpage suggests what to do
(nor should it, really), but the user is left with a bootloader that
appears fully funxional, since nothing suggests a failure in the output,
but with an unbootable machine, /no way to boot it/, even if they drop
to an EFI shell, since the boot bundle isn't present on the ESP,
and no real recourse even if they boot into a recovery system,
apart from installing like GRUB or whatever.
00- is purely instrumentation for 90-,
and separating one from the other has led to downstream dissatisfaxion
(indeed, the last mentioned commit cited cited exactly that as the
reversion reason), while creating $ENTRY_DIR_ABS is only required
for bootloaders using the BLS, and shouldn't itself toggle anything.
To that end, introduce an /{e,l}/k/install.conf file that allows
overriding the detected layout, and detect it as "bls" if
$BOOT_ROOT/$MACHINE_ID ($ENTRY_DIR_ABS/..) exists, otherwise "other" ‒
if a user wishes to select a different bootloader,
like GRUB, they (or, indeed, the postinst script) can specify
layout=grub. This disables 90- and $ENTRY_DIR_ABS manipulation.
If KERNEL_INSTALL_MACHINE_ID is defined in /etc/machine-info, prefer it
over the machine ID from /etc/machine-id. If a machine ID is defined in
neither /etc/machine-info nor in /etc/machine-id, generate a new UUID
and try to write it to /etc/machine-info as KERNEL_INSTALL_MACHINE_ID
and use it as the machine ID if writing it to /etc/machine-info succeeds.
In practice, this means we have a more robust fallback if there's no
machine ID in /etc/machine-id than just using "Default" and allows
image builders to force kernel-install to use KERNEL_INSTALL_MACHINE_ID
by simply writing it to /etc/machine-info themselves.
Confer https://github.com/systemd/systemd/pull/19006#issuecomment-800234022:
On some systems it's the admin's explicit choice not to to have the
machine ID leak into the ESP
On some systems the machine ID is transient, generated at every boot,
and hence should not be written to the ESP
