While Linux kernel developers have already been working on ACPI 5.1 support since it brings ACPI on ARM, and there's partial support in the Linux 3.17 kernel, the UEFI Forum today finally announced the official release of the ACPI 5.1 specification.

Version 5.0 of the Advanced Configuration and Power Interface (ACPI) brings most notably 64-bit ARM (ARMv8 / AArch64) support. There's additionally a new Collaborative Processor Performance Control (CPPC) extension, new device-specific data control support, and other improvements to the specification.

More details on ACPI 5.1 can be found via the UEFI Forum press release.