systemd 254-rc2 Brings A Few More Changes

Earlier this month brought the release of systemd 254-rc1 with a new soft-reboot mechanism, officially deprecating System V scripts, a new systemd-battery-check process that runs at boot to check any system battery level status, and various other changes. On Friday systemd 254-rc2 was released with a few more changes.

Besides the usual fixes and other maintenance updates, systemd 254-rc2 brings a few more alterations to the new features of this major summer 2023 software update.

With systemd 254-rc2, a means of disabling the new systemd-battery-check functionality can be disabled. If setting the systemd.battery-check=0 option on the kernel command-line when booting, this battery checking service will be skipped. The default behavior with systemd 254's new service is that if the battery level is very low the user will be warned at boot-time and the system subsequently turned off automatically after a brief delay. Understandably this new default workflow may frustrate some users and thus the new systemd.battery-check=0 override.

Another late addition to systemd 254 is around its handling of confidential virtual machines. For "confidential virtual machines", SMBIOS strings and QEMU fw_cfg protocol will not be used for importing credentials and kernel command line parameters by the system manager, systemd-boot, and systemd-stub. In such confidential settings this data from the hypervisor is considered untrusted.

Aside from those alterations, it's mostly general fixes making it into the RC2 release.

The full list of changes coming with systemd 254 as of yesterday's RC2 milestone can be found via the GitHub announcement. Look for the stable systemd 254 release to happen soon and in turn for this version to be picked up by the autumn 2023 Linux distribution releases.