Posted on February 26, 2014 · Posted in Windows 8

UEFI and Windows 8

In this article we explore the concept of UEFI notion and with appliance of this technology in Windows 8.

What is UEFI technology? UEFI abbreviation is short for Unified Extensible Firmware Interface. This technology is designed for traditional computer boot system modification and should replace obsolete BIOS system. But it is not just old technology modernization it is a fundamentally new approach to OS and computer booting technology. In fact UEFI has practically nothing to do with PC BIOS systems.

If BIOS is code (non flexible and virtually unchangeable), flashed in a special BIOS chip on system board, UEFI is a flexible programmable interface located above all computer hardware components with their own firmware. UEFI code (is much bigger in size than BIOS booting code) is allocated in special folder /EFI/ which can be stored in widely different places from a separate chipset on system board to hard drive partition or system storage. In fact UEFI is an independent lightweight operating system which represents an interface between main OS and micro programs which control low-level hardware equipment functions that should directly initialize equipment and transfer control to main (“big”) OS loader.   uefi interface

UEFI contain hardware testing and booting services, and also the realizations of standard communication protocols (including network), devices drivers, functional extensions and even EFI-shell in which special EFI application can be started. I.e. you can connect to the Internet at UEFI level already, or organize hard drive backup with a help of graphic GUI.

In one or two years UEFI specification will be used in all industry leading motherboards and it will be almost impossible to find a new PC with standard BIOS. Among the most popular UEFI peculiarities which can be realized on the computer which works on it, are Secure Boot, low level cryptography, network authentication, universal graphic drivers, etc. UEFI supports 32 and 64 bits processors and can be used on systems with Itanium x86, x64, and ARM processors.

All modern operating systems support (Windows, Linux, OS X) booting through UEFI.

However if UEFI usage in MacOS X (Bootcamp  boot manager) and Linux is quite superficial the advantages on UEFI environment in Windows 8 can be used to the maximum.

For old OS support (which supports only BIOS) in UEFI exist BIOS emulation mode which is called Compatibility Support Module (CSM).  

UEFI and Windows 8 support

What advantages can you get by simultaneous usage of UEFI and Windows 8?

One of the main advantages is safe boot technology opportunity which allows to prevent unwanted programs execution during PC initializing (we will discuss details of safe boot technology in the separate article).

Thanks to UEFI Windows 8 can be installed on drives with 3 Tb and more volume, and, correspondingly boot from this drives. This is connected with transfer from MBR partition table (in BIOS) to GPT (UEFI)

UEFI usage instead of BIOS is one of the key moments which provides fast Windows 8 boot (UEFI code works faster because it was written from the ground up without a necessity of entailing all old rules and compatibilities with it). Besides while reading a special file block size EFI I/O is used in UEFI. It allows reading up to 1 Mb of data at a time (64 Kb in BIOS). More over boot time decrease is achieved because there is no necessity of loader search on all devices, in UEFI the boot drive should be appointed at OS installation level

So we mentioned that Windows 8 supports UEFI boot, however there is range of peculiarities:

  • Computer should be compatible with UEFI v2.3.1
  • UEFI is supported only by 64-bit Windows 8. 32- bit version do not support UEFI functions (on new computers this OS will have to work in CSM emulation mode).
  • Windows 8 for ARM (Windows RT) won`t be working on equipment which doesn’t support UEFI or which allows Secure Boot disabling.

To install Windows 8 on equipment UEFI, you must use a specially prepared USB flash boot drive. Details in the article: How to create a UEFI bootable USB flash drive for install Windows 8

Developers planned to implement a lot of UEFI other functions in next Windows versions (and nearest Windows 8.1) such as Rootkit prevention (rootkit detection during boot process), Network authentication (authentication during boot, especially relevant in remote OS expanding script) etc.

Access to UEFI settings from Windows 8

It`s worth  mentioning that on new computers with pre-installed Windows 8 which uses UEFI well known trick of pressing Delete and F2 buttons (or any other buttons appointed by vendor) while trying to get in UEFI settings won’t work. Because Windows 8, especially on SSD boot so quickly that you hardly have time to press a button for UEFI settings mode entry. There was an information that Windows 8 on SSD with UEFI waits for button pressing only for 200 ms. That’s why there is a procedure of UEFI parameters settings program call from Windows 8 boot menu.

You can get in Windows boot menu using one of three ways.

  1. In PC settings select general section and press “Restart now” button in advance startup section. restart windows 8
  2. The same effect can be achieved by pressing Shift and Restart – buttons in Shutdown menu.shift + restart buttons in win 8
  3. Another way of getting in windows boot menu is by performing  next command in the command line:
    shutdown.exe /r /o /f /t 00

After the restart Windows 8 boot menu will open automatically, you should select  Troubleshoot->Advanced options on it. Separate UEFI firmware settings button in advanced options window will allow you to get directly in computer BIOS after PC restart (in fact this is UEFI, the settings of which are equal to traditional PC BIOS). get uefi firmware settings in windows 8

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