Since BIOS updates became possible, the process required restarting the PC. Even when motherboard makers made a complete switch to UEFI, this remained the case. Intel is changing that, thanks to a new part of the ACPI specification called Platform Firmware Runtime Update and Telemetry (PFRUT). This allows updating the BIOS or UEFI firmware of a PC without forcing a restart. Windows users, however, will be disappointed. The functionality is only Linux, at least for now.
Intel has been working on PFRUT for some time, previously under the nickname “Seamless Update”. The idea is to reduce downtime, especially for servers which should ideally remain available 100% of the time. Servers can undergo “on-the-fly” BIOS / UEFI updates, keeping critical workloads fully operational at all times.
The next “pfr_update” driver should be introduced in the Linux 5.17 kernel. Sources say it appears to be designed for system firmware updates in the event of critical bugs or security issues, allowing server administrators to patch their hardware without downtime.
The current BIOS / UEFI update procedure requires the operating system to download the new firmware to the BIOS. On restart, the firmware is transmitted to the motherboard to “flash” the BIOS or UEFI. Under the PFRUT driver set, the update is handled entirely by the operating system, without restarting the computer.
Currently the driver update is located in the “linux-next” branch. This means that it should be in the next stable kernel cycle, coming in mid-January. Phoronix, who first noticed the new driver set, says this is a “server exclusive” feature. This means that it may or may not be included in mainstream Linux distributions. Since this is an open source project, there is a good chance that desktop Linux operating systems will integrate it as well.
Again, this is a Linux-only capability, but that doesn’t mean it always will be. PFRUT is a feature included in the ACPI power management specification, so it may arrive on Windows and other desktops in the future.