Libreboot is a distribution of coreboot — the open-source firmware that replaces a board's proprietary BIOS/UEFI — bundled with free bootloaders and payloads, maintained as a project aiming at fully free system firmware. Its constraint has never really been the coreboot core; it has been the boot path. Coreboot hands control to a payload, and for years the practical choices for Libreboot users were legacy/BIOS-style payloads such as GRUB or SeaBIOS. On machines whose firmware had dropped the Compatibility Support Module — the shim that lets UEFI systems boot legacy option ROMs — that path was simply unavailable.
heise reports that Libreboot can now boot via UEFI. In practice that means coreboot is paired with a UEFI payload, so the machine presents the operating system with a standard UEFI environment instead of a legacy one — the EDK2/Tianocore lineage that vendors such as System76 already use in their coreboot firmware.
Why it matters: Intel and the board vendors have been deleting CSM support, and UEFI-only boot is now the norm on new hardware. A free-firmware distribution without a UEFI path is a distribution that cannot follow its users onto new machines at all.
One honest caveat: boot compatibility is not the same as blob-freedom. On most modern x86 platforms, coreboot still depends on vendor-supplied binaries — Intel's Management Engine and FSP, AMD's PSP — so a UEFI-capable Libreboot build widens the set of machines that will start, not necessarily the set that runs with zero proprietary firmware.
For users the practical question is which specific boards the new UEFI path has been validated on; Libreboot's documentation has always been board-by-board rather than generic.
