Intel To Sunset Legacy BIOS Support By 2020 In Favor Of UEFI Class 3

Intel is getting ready to kick legacy BIOS support to the curb, with future platforms taking full advantage of the UEFI Class 3, the most recent version of UEFI. That is already the case for many Intel systems already shipping. By 2020, Intel wants to move on completely, removing BIOS support from UEFI. That means all of its client and datacenter platforms will no longer have a legacy BIOS mode.

BIOS
Image Source: Flickr (Paul Schultz)

BIOS, or Basic Input/Output System, is the firmware that initializes hardware when booting up a system. It worked fine for a time, but by around the mid 1990s, its limitations starting catching up to newer systems, in particular larger server platforms that Intel was going after with Itanium. Intel had begun working on a replacement to the BIOS, which was later adopted by the Unified EFI Forum.

Fast forward to today and most new systems now run UEFI, or Unified Extensible Firmware Interface. It is far more robust than the legacy BIOS, with support for newer architectures, a more intuitive graphical user interface (GUI), and things like remote diagnostic support even when there is no operating system. Most implementations also provide legacy BIOS support for clients who need it, which they can enable through the Compatibility Support Module (CMS). That is what Intel is changing.

UEFI Classes
Source: UEFI.org

Going forward, Intel will require UEFI Class 3 (or higher). That will essentially break any customer process that still depends on disabling UEFI through CSM. However, it's not as dire as it sounds. Intel is not making Secure Boot mandatory, a feature that is tied to UEFI, so clients will be able to run unsigned Linux distributions on PCs with UEFI.

Where things could get tricky is when running into compatibility issues on older hardware. Intel acknowledges in a PDF presentation this move will "break any customer process that depends on 'disabling UEFI'. To account for that, Intel is working with industry partners to "eliminate components with no UEFI support" so this doesn't become an ongoing issue.

Thumbnail Image Source: Flickr (Nick Gray)