Intel will kill off legacy BIOS support in favor of UEFI by 2020

Intel will kill off legacy BIOS support in favor of UEFI by 2020

Intel has announced that it will stop supporting the venerable PC BIOS by 2020. Instead, it will fully transition to UEFI firmware, citing improved security as one of the main reasons.

BIOS, or Basic Input/Output System, is a small segment of low-level code that is embedded on a PC’s motherboard and handles things like the initialization and booting of hardware.

However, even though the BIOS has evolved over time, it’s still woefully outdated. For instance, it needs to run in a 16-bit processor mode and can only boot from drives of 2.1TB or less. Furthermore, it isn’t good at initializing multiple hardware devices at once, which results in slower boot times with all the devices commonly hooked up to a modern PC.

In 2007, major firms like Intel, AMD, Microsoft and PC vendors agreed on the Unified Extensible Firmware Interface specification, or UEFI. The 64-bit version of Windows Vista Service Pack 1 also introduced the ability to boot from UEFI.

UEFI offers several improvements, such as support for far larger drives and 64-bit mode. It also has a larger address space than BIOS’ paltry 1MB, so boot times are reduced as well. More importantly, it also offers better security.

Today, the vast majority of computers and motherboards ship with UEFI instead of the older BIOS, although the latter term is frequently used to refer to UEFI anyway. These generally fall under the category of UEFI Class 2, where it’s possible to add BIOS support through a Compatibility Support Module (CSM).

This allows modern systems to boot old software and support old hardware, but many newer PCs ship with CSM disabled because a security feature called Secure Boot only works with CSM disabled. What’s more, for hardware to be certified with the Windows logo, Secure Boot has to be enabled.

Intel now plans to dispense with CSM, which could potentially simplify the hardware validation process as developers no longer need to check that their products work with both CSM enabled and disabled.

It could also open the path to removing legacy support on Intel’s own hardware, such as 16-bit compatibility on existing 32- and 64-bit processors.  

One issue is that the number of older OSes in use, such as DOS, 32-bit versions of Windows before Windows 7, and 64-bit versions preceding Windows Vista, is not insignificant. By 2020, the ability to boot these and other legacy software will disappear.

Source: UEFI Plugfest