The official announcement of Windows 11 was supposed to go smoothly, but Microsoft managed to create a real firestorm over its minimum requirements. Unfortunately, the doubts don't end with knowing whether your computer is compatible with Windows 11, or with enabling TPM 2.0. When reading the specs, many users get confused by terms that are basic to us. What does UEFI mean? What is the BIOS? What is firmware? The first step to answering those questions is to put the terms in order…
What is firmware?
The most basic definition of firmware tells us it is a "program or piece of software" responsible for providing low-level access and control of a device's hardware. Depending on that device's functions, firmware can enable essential aspects, or on the contrary, function as a complete operating system.
One of the most everyday examples of firmware in action we can share is the remote control. Its firmware contains all the codes and commands to control the television, and in the vast majority of cases it does not need to be modified. However, there is the case of universal remotes, which allow a certain level of programming to adapt to a specific model. In the world of computing, many devices are unable to function correctly without the appropriate firmware.
What is the BIOS?
BIOS stands for "Basic Input/Output System" and is a variant of firmware responsible for providing hardware initialization functions during a computer's boot process. The name "BIOS" dates back to 1975 and was inherited from the "Basic Input/Output System" used by the CP/M operating system.
The history of the BIOS changed forever with the launch of the IBM PC. That computer used a proprietary BIOS exclusive to IBM, but several companies applied reverse engineering and managed to create different "IBM PC Compatible" BIOSes, turning it into a market standard that has not left us in almost four decades.
In current systems, the BIOS initializes and runs diagnostics on basic hardware components, and loads a boot loader that leads to the actual startup of the operating system. In its early years, the only way to update a BIOS was replacing the chips on the motherboard, but now they use Flash technology, and updates are obtained through its manufacturer.
Why is this important? Because computers that use a traditional BIOS or its "compatibility mode" will not be able to receive Windows 11. Systems will have to work in "native UEFI mode", and thus we arrive at the last question…
What is UEFI?
Unified Extensible Firmware Interface, or UEFI, is a specification focused on defining a software interface between a platform's firmware and its operating system. UEFI was designed to serve as a direct replacement for the BIOS, but it is not exactly recent. The original specifications were created by Intel under the name Intel Boot Initiative in 1998, becoming Extensible Firmware Interface, or EFI, shortly after. However, Intel withdrew EFI and joined the development of UEFI in 2005.
EFI was the answer to several of the original BIOS's limitations, such as the 16-bit real mode and the use of assembly language. At that time, Intel had bet everything on the development of Itanium processors, and that hardware needed something more elaborate than a traditional BIOS. Today, UEFI has found its place in millions of modern motherboards, while Itanium will be officially retired in July 2021.
Updating a motherboard's UEFI follows a procedure similar to the BIOS (you need to get the correct update from the manufacturer), but they are definitely different creatures. The level of control and customization offered by current UEFIs is far superior, however, their complexity has also increased, and we can confidently say that every board comes with a "mini-operating system" inside.
In summary
Firmware is a small program that allows us to control our hardware and also guarantees its operation. The BIOS is a form of firmware that initializes and coordinates a computer's hardware, and UEFI is the technology that replaces it. Windows 11 will only work on those machines that have a UEFI solution, but that is not the only requirement. We hope this has been helpful. Good luck!
