Libreboot (briefly known as GNU Libreboot) is a free and open-source software project based on coreboot, aimed at replacing some of the proprietary BIOS or UEFI firmware on supported x86-64 and AArch64 computers. Libreboot performs the basic machine setup such as CPU initialization or memory controller initialization necessary to load and run a 32-bit or 64-bit operating system, such as Linux or FreeBSD.