71c8bf2837
Boot loaders are software like any other, and hence muse be updated in regular intervals. Let's add a simple (optional) service that updates sd-boot automatically from the host if it is found installed but out-of-date in the ESP. Note that traditional distros probably should invoke "bootctl update" directly from the package scripts whenver they update the sd-boot package. This new service is primarily intended for image-based update systems, i.e. where the rootfs or /usr are atomically updated in A/B style and where the current boot loader should be synced into the ESP from the currently booted image every now and then. It can also act as safety net if the packaging scripts in classic systems are't doing the bootctl update stuff themselves. Since updating boot loaders mit be a tiny bit risky (even though we try really hard to make them robust, by fsck'ing the ESP and mounting it only on demand, by doing updates mostly as single file updates and by fsync()ing heavily) this is an optional feature, i.e. subject to "systemctl enable". However, since it's the right thing to do I think, it's enabled by default via the preset logic. Note that the updating logic is implemented gracefully: i.e. it's a NOP if the boot loader is already new enough, or was never installed.
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list or join our IRC channel.
Stable branches with backported patches are available in the stable repo.