Required for integration tests to power off on PID 1 crashes. We
deprecate systemd.crash_reboot and related options by removing them
from the documentation but still parsing them.
As I noticed a lot of missing information when trying to implement checking
for missing info. I reimplemented the version information script to be more
robust, and here is the result.
Follow up to ec07c3c80b
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.
As mentioned in the NEWS entry, it seems to see very little use, but adds
complexity in our code. It was added mainly with the goal of making it easier
for people using grub2 to modify their boot configuration, but grub2 is gaining
support for BLS snippets. On the systemd side, we now have credentials. So
let's deprecate this, and if there's no outcry, remove it in a few releases.
Let's hook up one more thing with credentials: the machine ID to use
when none is initialized yet.
This requires some reordering of initialization steps in PID 1: we need
to import credentials first, and only then initialize the machine ID.
Let's move the long explanation to the man page of the component that
interprets the credential, and keep only a brief summary in
systemd.system-credentials(7).
ImportCredential= takes a credential name and searches for a matching
credential in all the credential stores we know about it. It supports
globs which are expanded so that all matching credentials are loaded.
The general idea is that users should be able to figure out if some option
that they see in a config file or on some internet page is something that
systemd knows about. Once users know that, yes, this was an option but has
been deprecated and removed from the documentation, it's much easier for them
to find any docs in old versions if they want to. Or to switch to something
different.
This imports credentials also via SMBIOS' "OEM vendor string" section,
similar to the existing import logic from fw_cfg.
Functionality-wise this is very similar to the existing fw_cfg logic,
both of which are easily settable on the qemu command line.
Pros and cons of each:
SMBIOS OEM vendor strings:
- pro: fast, because memory mapped
- pro: somewhat VMM independent, at least in theory
- pro: qemu upstream sees this as the future
- pro: no additional kernel module needed
- con: strings only, thus binary data is base64 encoded
fw_cfg:
- pro: has been supported for longer in qemu
- pro: supports binary data
- con: slow, because IO port based
- con: only qemu
- con: requires qemu_fw_cfg.ko kernel module
- con: qemu upstream sees this as legacy
