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What does uefi mean in BIOS. Useful UEFI features. New security technology

1. What is UEFI?
UEFI (Unified Extensible Firmware Interface) is a replacement for BIOS, which better meets the requirements of modern diverse hardware. At its core, UEFI is an interface that is responsible for the pre-boot environment of the operating system.

2. What are the advantages of UEFI over BIOS?

  • Support for media >2TB
  • Easier preparation bootable media, no need to write different boot sectors
  • Availability of your own download manager. Now it is not necessary to create a multi-level leapfrog of bootloaders in order to organize a multiboot environment; EFI NVRAM regularly stores all records about existing bootloaders, and switching between bootable operating systems is carried out in the same way as between bootable media.
  • More secure boot environment
  • Graphics UEFI configuration mode, with graphics and mouse support

3. Is it possible to update my BIOS to UEFI?
Not really. UEFI cannot be flashed instead of BIOS, since it takes much more more memory. But there is such a thing as DUET. This is a BIOS-bootable UEFI environment that can be useful if you intend to use >2TB drives on your older BIOS hardware.

4. Is it possible to boot from UEFI, as before, through boot sectors and MBR disks?
Yes, if Legacy Boot support is enabled in the UEFI configuration

5. What is GPT?
GUID Partition Table, GPT - standard format for placing partition tables on a hard drive. It is part of the EFI interface. EFI uses GPT where BIOS uses MBR.

6. What are the advantages of GPT over MBR?

  • Support for media >2.2TB
  • No limitation on 4 main partitions, and as a result, no need for logical partitions
  • Increased security - GPT stores backup copy partition tables at the end of the disk, so in case of problems it is possible to restore the partition using a spare table.
  • Protection against corruption by outdated programs using Protective MBR
  • It is possible to use old boot sectors.

7. Where are the equivalent boot sectors stored in GPT?
EFI uses the EFI/boot folder, located at the root of the FAT32 partition, to store boot loaders. The default file should be /EFI/boot/bootx64.efi
If the boot disk is partitioned in MBR style, then the presence of a FAT32 file system on the first partition (if there are several of them) and a file with a bootloader located on the default path are the only conditions for booting from this media (CD/DVD are also supported). If the disk is partitioned in GPT style, the partition does not have to be the first one, but it must have the boot flag (you can check and set it using gparted)

8. Is it possible to convert a disk from MBR to GPT and back without losing data?
Yes. To do this, you will need a bootable disk/flash drive with Gparted. After booting from the bootable media, the gparted window will open with the scratch disk (usually /dev/sda) displayed in the upper right corner. You need to remember the name of the disk that you want to convert, open a terminal, and type sudo gdisk /dev/sda where instead of sda, if necessary, you need to substitute the name of your disk. Then you need to enter the w command and confirm writing the GPT table to disk. That's it, the disk has been converted to a GPT table. To convert back to MBR, you need to open gdisk for your disk in the same way, and sequentially type the command r, then g, and then confirm the entry of the new table using the w command.

9. What is UEFI Shell?
This is an environment for working with an EFI (terminal-like) environment, which allows you to run efi-compatible bootloaders on the go, perform simple operations with files, and also operate the built-in boot manager.

10. How to edit/delete/add download items to boot menu UEFI?
Download UEFI Shell, copy it to the file /EFI/boot/bootx64.efi on a FAT32 flash drive, and boot from it. After the shell has successfully loaded, a command prompt should appear
Shell>
Above the prompt you should see a list of available connected drives (fs0:, fs1:, BLK0, etc.). To call this list again if necessary, use the command
map fs*
From the full drive name you can glean some information about the drive. For example:
PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)/HD(1,MBR,0x27212721,0x3F,0x13FA6D9)
from here
Ata(0x0) - disk connection interface, as well as controller port
HD is HDD
1 - number of partitions on the disk
MBR partitioning scheme

Having thus found required disk, you need to go to it
fs0:
then, using the good old DOS commands dir and cd, you need to find and go to the directory with the boot efi files. This is usually /EFI/boot/. Then, while in this directory, you can enter the name of the bootloader file and immediately boot into it. To add the desired file to the list of boot entries, it is advisable to first read the existing entries using the command
bcfg boot dump
Then, to add the boot file to this list, you need to enter
bcfg boot add N filename.efi "label"
Where N is the serial number of the entry (if there was something in its place, this item will be overwritten)
filename.efi - name of the file with the loader
label-name under which this entry will be displayed in the list
You can view the list of boot entries again via
bcfg boot dump
and make sure everything is in place. You can reboot and check.
To remove an entry from the list, use the command
bcfg boot rm N
where N is the record number

11. What is Secure Boot?
The Secure Boot specification was developed by Microsoft as part of the UEFI project and allows you to protect the boot environment from tampering with boot files by monitoring the signatures of boot files for compliance with the white list of keys hardcoded into uefi as trusted. A “side effect” of such protection against rootkits is the impossibility of installing an OS other than Windows 8 (on this moment only it supports Secure Boot), and also excludes the possibility of starting from old mbr disks and bootable CDs/flash drives.

12. How to disable Secure Boot?


13. How to make a UEFI-compatible flash drive with an OS distribution?
In most cases, everything is very simple:

  1. Format the flash drive to file system FAT32
  2. Copy the entire contents of the distribution iso image to it

But in the case of Windows Vista/7 OS, you will need to prepare the distribution kit first, because they initially do not contain EFI files in the right places. Just a small disclaimer - Windows supports working with uefi only in 64-bit editions.

14. How do you know that the bootable USB flash drive is made correctly and will boot in UEFI mode?
If everything is done correctly, then two devices with the same name but different prefixes should appear in the list of bootable media, UEFI: And USB:. Through the first, loading is carried out in UEFI mode, through the second, Legacy loading from the boot sector.

15. What is Fast Boot Mode?
Fast boot mode, in which control is almost immediately transferred to the operating system, even before the equipment is ready for operation, which is initialized by the OS itself. Fast Boot eliminates delays caused by double initialization of devices. In the “classic” mode, after receiving control, the operating system reinitializes previously initialized Device BIOS. Considering that initialization of some types of devices is a rather lengthy process, the speed gain is obvious. When Fast Boot is enabled, control is transferred to the system before USB is initialized, which makes USB drives and keyboards unavailable before the start installed on the system disk. Since Microsoft has fairly strict requirements for the time it takes to install the firmware when Fast Boot mode is enabled, and initialization of USB devices can take seconds, by the time the system starts, USB devices remain uninitialized. In this case it appears back side medals - a computer user with a USB keyboard cannot interrupt the boot process and initiate the installation of another system, since the keyboard remains inoperative until the OS starts. Moreover, initializing the i8042 chip also takes time, and on some laptops, firmware manufacturers leave the built-in PS/2 keyboard uninitialized.

Many users believe that the computer boots using the operating system, but in fact this is only partly true. In this material, you will learn how a PC actually boots and become familiar with such important concepts as BIOS, CMOS, UEFI and others.

Introduction

For many people, working with a computer begins after loading the operating system. And this is not surprising, since the vast majority of the time, modern PCs are actually used using the convenient graphical shell of Windows or any other OS. In this friendly environment for us, we not only launch programs, applications or games, but also carry out settings, as well as configure system parameters to suit our own needs.

But, despite all its multifunctionality, the operating system cannot do everything, and in some key moments, it is simply powerless. In particular, this applies to the initial boot of the computer, which occurs completely without her participation. Moreover, the launch of the OS itself largely depends on the success of this procedure, which may not occur if problems arise.

This may be news to some, but in reality, Windows is not responsible for booting the computer from start to finish; it only continues it at a certain stage and finishes it. The key player here is a completely different firmware - the BIOS, the purpose and main functions of which we will talk about in this material.

What is BIOS and why is it needed?

The key components of any computer device are the processor and random access memory, and this is not without reason. The processor is rightly called the heart and brain of any PC, since all the main mathematical operations are entrusted to it. In this case, the CPU can only take all commands and data for calculations from RAM. He also sends the results of his work there. The processor does not directly interact with any other information storage, for example, hard drives.

This is where the main problem lies. In order for the processor to begin executing operating system commands, they must be in RAM. But when the PC is turned on, the RAM is empty, since it is volatile and cannot store information when the computer is turned off. At the same time, on their own, without the participation of the system, computer devices they cannot place the necessary data in memory. And here we are faced with a paradoxical situation. It turns out that in order to load the OS into memory, the operating system must already be in RAM.

To resolve this situation, at the dawn of the era of personal computers, IBM engineers proposed using a special small program called the BIOS, sometimes called the bootloader.

Word BIOS(BIOS) is an abbreviation for four English words Basic Input/Output System, which translated into Russian means: “Basic input/output system.” This name was given to a set of firmware responsible for the operation of the basic functions of video adapters, displays, disk drives, drives, keyboards, mice and other basic input/output devices.

The main functions of the BIOS are the initial startup of the PC, testing and initial configuration of the equipment, distribution of resources between devices and activation of the operating system boot procedure.

Where is the BIOS stored and what is CMOS

Considering that the BIOS is responsible for the very initial stage of booting the computer, regardless of its configuration, this program should be available for basic devices immediately after pressing the PC power button. That is why it is not stored on the hard drive, like most ordinary applications, but is written to a special flash memory chip located on system board. Thus, access to the BIOS and starting the computer is possible even if no storage media is connected to the PC at all.

The very first computers used read-only memory (ROM) chips to store the BIOS, onto which the program code itself was written once at the factory. Somewhat later, EPROM and EEROM chips began to be used, in which it was possible, if necessary, to rewrite the BIOS, but only with the help of special equipment.

In modern personal computers The BIOS is stored in chips based on flash memory, which can be rewritten using special programs directly on a PC at home. This procedure is usually called flashing and is required to update the firmware to new versions or replace it in case of damage.

Many BIOS chips It is not soldered onto the motherboard, like all other components, but is installed in a special small connector, which allows you to replace it at any time. Is it true, this opportunity It is unlikely to be useful to you, since cases requiring replacement of the BIOS chip are very rare and practically never occur among home users.

Flash memory for BIOS storage can have different capacities. In previous times, this volume was very small and amounted to no more than 512 KB. Modern versions of the program have become somewhat larger and have a volume of several megabytes. But anyway in the background modern applications And multimedia files it's just minuscule.

In some advanced motherboards, manufacturers can install not one, but two BIOS chips at once - a main one and a backup one. In this case, if something happens to the main chip, the computer will boot from the backup one.

In addition to the flash memory in which the BIOS itself is stored, there is another type of memory on the motherboard that is designed to store configuration settings for this program. It is manufactured using a complementary metal oxide semiconductor or CMOS(Complementary Metal Oxide Semiconductor). This is the abbreviation they call specialized memory, which contains computer startup data used by the BIOS.

CMOS memory is powered by a battery installed on the motherboard. Thanks to this, when you unplug the computer from the outlet, everything BIOS settings are saved. On older computers, CMOS memory functions were assigned to a separate chip. In modern PCs it is part of the chipset.

POST procedure and initial PC boot

Now let's see what the initial process of booting a computer looks like and what role the BIOS plays in it.

After pressing the computer's power button, the power supply starts up first, starting to supply voltage to the motherboard. If it is normal, then the chipset gives a command to reset the internal memory of the central processor and start it up. After this, the processor begins to sequentially read and execute commands written in system memory, the role of which is played by the BIOS chip.

At the very beginning, the processor receives a command to perform self-testing of computer components ( POST- Power-On Self-Test). The POST procedure includes several stages, most of which you can watch on the PC screen immediately after turning it on. The sequence of events before the operating system starts loading is as follows:

1. First, the main system devices are determined.

3. The third step is setting up the system logic set, or more simply, the chipset.

4. Then the video card is searched and identified. If an external (independent) video adapter is installed in the computer, then it will have its own BIOS, which the main system BIOS will look for in a certain range of memory addresses. If an external graphics adapter is found, the first thing you will see on the screen will be an image with the name of the video card generated by its BIOS.

5. After finding graphics adapter, integrity check begins BIOS settings and battery condition. At this moment, those same mysterious white inscriptions begin to appear on the monitor screen one after another, causing trepidation in inexperienced users due to a lack of understanding of what is happening. But in fact, nothing supernatural happens at this moment, as you will now see for yourself. The first, topmost inscription, as a rule, contains the logo of the BIOS developers and information about its installed version.

6. Then testing of the central processor starts, after which data about the installed chip is displayed: the name of the manufacturer, model and its clock frequency.

7. Next, testing of RAM begins. If everything goes well, the total installed amount of RAM is displayed on the screen with the inscription OK.

8. Upon completion of checking the main components of the PC, the search for the keyboard and testing of other input/output ports begins. In some cases, the computer may stop booting at this stage if the system is unable to detect the connected keyboard. In this case, a warning about this will be immediately displayed on the screen.

9. Next, the detection of storage devices connected to the computer begins, including optical drives, hard drives and flash drives. Information about the found devices is displayed on the screen. In the event that several controllers from different manufacturers, then the procedure for their initialization can be displayed on different screens.

Controller Definition ScreenSerialATA, which has its ownBIOS, with the output of all devices connected to it.

10. At the final stage, resources are distributed between the found internal PC devices. In older computers, after this a summary table with all detected equipment is displayed. IN modern cars the table is no longer displayed.

11. Finally, if the POST procedure is successful, the BIOS begins searching the connected drives Main Boot Area(MBR), which contains data about the operating system startup and the boot device to which further control must be transferred.

Depending on the BIOS version installed on the computer, the POST procedure may take place with slight changes from the order described above, but in general, all the main steps that we have indicated will be performed when booting each PC.

BIOS Setup Utility

BIOS is a configurable system and has own program settings of some PC hardware parameters, called BIOS Setup Utility or CMOS Setup Utility. It is called by pressing a special key during the POST self-test procedure. On desktop computers, the Del key is most often used for this purpose, and on laptops F2.

The graphical interface of the hardware configuration utility is very ascetic and has remained virtually unchanged since the 80s. All settings here are made only using the keyboard - mouse operation is not provided.

CMOS/BIOS Setup has a lot of settings, but the most popular ones that the average user may need include: setting the system time and date, choosing the order of boot devices, enabling/disabling additional equipment built into the motherboard (sound, video or network adapters) , controlling the cooling system and monitoring the processor temperature, as well as changing the system bus frequency (overclocking).

U various models motherboards, the number of configurable BIOS parameters can vary greatly. The widest range of settings usually have expensive motherboards for desktop PCs, aimed at enthusiasts, hobbyists computer games and acceleration. The meager arsenal, as a rule, is found in budget boards designed for installation in office computers. The vast majority of BIOS settings also do not shine with a variety of settings. mobile devices. We will talk in more detail about the various BIOS settings and their impact on the operation of the computer in a separate article.

BIOS development and update

As a rule, for almost every motherboard model, a own version BIOS, which takes into account its individual technical features: the type of chipset used and the types of peripheral equipment soldered.

BIOS development can be divided into two stages. First, a basic version of the firmware is created, which implements all functions, regardless of the chipset model. Today, the development of such versions is mainly carried out by companies American Megatrends(AMIBIOS) and Phoenix Technologies, which in 1998 absorbed the then major player in this market - Award Software (AwardBIOS, Award Modular BIOS, Award WorkstationBIOS).

At the second stage, motherboard manufacturers are involved in the development of BIOS. At this point, the basic version is modified and improved for each specific model board, taking into account its features. At the same time, after the motherboard enters the market, work on its BIOS version does not stop. Developers regularly release updates that can fix found errors, add support for new hardware, and expand the functionality of the program. In some cases, updating the BIOS allows you to breathe new life into a seemingly outdated motherboard, for example, adding support for a new generation of processors.

What is UEFI BIOS

Basic principles of system BIOS operation for desktop computers were formed in the distant 80s of the last century. Over the past decades, the computer industry has developed rapidly and during this time situations have constantly occurred when new device models turned out to be incompatible with certain versions BIOS. To solve these problems, developers constantly had to modify the code of the basic input/output system, but in the end whole line software limitations have remained unchanged since the days of the first home PCs. This situation led to the fact that the BIOS in its classic version finally ceased to meet the requirements of modern computer hardware, preventing its distribution in the mass sector of personal computers. It became clear that something needed to change.

In 2011, with the launch of production of motherboards for processors Intel generation Sandy Bridge installed in the LGA1155 socket, started mass implementation new software interface to boot the computer - UEFI.

In fact, the first version of this alternative to the regular BIOS was developed and successfully used by Intel in server systems back in the late 90s. Then, the new interface for booting a PC was called EFI (Extensible Firmware Interface), but already in 2005 its new specification was called UEFI (Unified Extensible Firmware Interface). Today, these two abbreviations are considered synonymous.

As you can see, motherboard manufacturers were in no particular hurry to switch to the new standard, trying to improve traditional BIOS variations until the last minute. But the obvious backwardness of this system, including its 16-bit interface, the inability to use more than 1 MB of memory address space, the lack of support for drives larger than 2 TB and other constant insoluble compatibility problems with new equipment nevertheless became a serious argument for switching to a new software solution .

What changes did the new boot interface proposed by Intel bring with it and how does it differ from the BIOS? As with BIOS, the main task of UEFI is to correctly detect the hardware immediately after turning on the PC and transfer control of the computer to the operating system. But at the same time, the changes in UEFI are so profound that it would be simply incorrect to compare it with BIOS.

BIOS is virtually unchangeable program code, sewn into a special chip and interacting directly with computer equipment using our own software. The procedure for booting a computer from using BIOS is simple: immediately after turning on the computer, the hardware is checked and simple universal drivers for the main hardware components are loaded. After this, the BIOS finds the operating system boot loader and activates it. Next, the OS loads.

The UEFI system can be called a layer between the computer's hardware components, with their own firmware, and the operating system, which allows it to also perform BIOS functions. But unlike BIOS, UEFI is a modular programmable interface that includes test, work and boot services, device drivers, communication protocols, functional extensions and your own graphical shell, which makes it look like a very lightweight operating system. At the same time, the user interface in UEFI is modern, supports mouse control and can be localized into several languages, including Russian.

An important advantage of EFI is its cross-platform and independence from the processor architecture. The specifications of this system allow it to work with almost any combination of chips, be it x86 architecture (Intel, AMD) or ARM. Moreover, UEFI has direct access to all computer hardware and platform-independent drivers, which makes it possible to organize, for example, Internet access or backup disks.

Unlike BIOS, the UEFI code and all its service information can be stored not only in a special chip, but also on partitions of both internal and external hard drives, as well as network storage. In turn, the fact that boot data can be placed on capacious drives makes it possible, due to the modular architecture, to provide EFI with rich functionality. For example, these could be advanced diagnostic tools, or useful utilities, which can be used both at the initial PC boot stage and after the OS starts.

Another key feature of UEFI is the ability to work with huge volume hard drives, partitioned according to GPT standard(Guid Partition Table). The latter is not supported by any BIOS modification, since it has 64-bit sector addresses.

Booting a UEFI-based PC, as in the case of BIOS, begins with initializing the devices. But at the same time, this procedure is much faster, since UEFI can detect several components at once in parallel mode (BIOS initializes all devices in turn). Then, the UEFI system itself is loaded, under the control of which any set of necessary actions is performed (loading drivers, initializing boot drive, starting boot services, etc.), and only after that the operating system starts.

It may seem that such a multi-step procedure should increase the overall boot time of the PC, but in fact the opposite happens. With UEFI, the system starts much faster, thanks to built-in drivers and its own bootloader. As a result, before starting, the OS receives comprehensive information about the computer’s hardware, which allows it to start within a few seconds.

Despite all the progressiveness of UEFI, there are still a number of restrictions that hinder the active development and distribution of this bootloader. The fact is that to implement all the capabilities of the new boot interface, it requires full support from operating systems. To date, only Windows 8 allows you to fully use the capabilities of UEFI. Limited support for the new interface is available for 64-bit versions of Windows 7, Vista and Linux with kernel 3.2 and higher. UEFI capabilities are also used in the BootCamp boot manager by Apple in its own Mac OS X systems.

Well, how does a computer boot from UEFI if it uses an unsupported operating system (WindowsXP, 32-bit Windows 7) or file partitioning (MBR)? For such cases, the new boot interface has built-in Compatibility support module(Compatibility Support Module), which is essentially a traditional BIOS. That is why you can see how many modern computers, equipped with motherboards with UEFI, boots in the traditional way in BIOS emulation mode. Most often this happens because their owners continue to use HDD partitions with a traditional MBR and don't want to move to GPT partitioning.

Conclusion

It's clear that, unlike a traditional BIOS, UEFI is capable of much more than just the boot process. The ability to launch working services and applications, both at the initial stage of PC boot and after the operating system starts, opens up a wide range of new opportunities for both developers and end users.

But at the same time, it is still premature to talk about a complete abandonment of the basic input/output system in the near future. First of all, you need to remember that until now most computers are running WindowsXP and 32-bit Windows 7, which are not supported by UEFI. Yes, and hard drives marked according to the GPT standard can mostly be found only in new laptop models based on Windows based 8.

So as long as most users, due to their habits or some other reasons, are tied to old versions of the OS and traditional methods of partitioning hard drives, BIOS will remain the main system for booting a computer.

  • Translation

Newer computers use UEFI firmware instead of the traditional BIOS. Both of these programs are examples of software low level, which runs when the computer starts before the operating system boots. UEFI is a newer solution, it supports larger hard drives, boots faster, is more secure - and, very conveniently, has a graphical interface and mouse support.

Some newer computers that ship with UEFI still call it "BIOS" to avoid confusion for users accustomed to traditional PC BIOSes. But even if you see it mentioned, know that your new computer, most likely, will be equipped with UEFI rather than BIOS.

What is BIOS?


BIOS stands for Basic Input-Output system, a basic input-output system. It is a low-level program stored on a chip on your computer's motherboard. The BIOS loads when you turn on your computer and is responsible for waking up its hardware components, making sure they are working correctly, and then launching the boot loader program, which starts the Windows operating system or any other operating system you have installed.

The BIOS setup screen allows you to change many settings. Computer hardware configuration, system time, boot order. This screen can be called up at the beginning of the computer boot by pressing a certain key - it is different on different computers, but the Esc, F2, F10, Delete keys are often used. By saving a setting, you store it in the motherboard memory. When you boot your computer, the BIOS will configure it as specified in the saved settings.

Before loading the operating system, the BIOS goes through POST, or Power-On Self Test, self-test after switching on. It checks that the hardware is configured correctly and is working properly. If something is wrong, you will see a series of error messages on the screen or hear a mysterious squeak from the system unit. What exactly do they mean sound signals described in the computer manual.

When the computer boots after POST, the BIOS looks for Master Boot Record, or MBR - master boot record. It is stored on the boot device and is used to launch the OS boot loader.

You may also have seen the acronym CMOS, which stands for Complementary Metal-Oxide-Semiconductor. It refers to the memory in which the BIOS stores various settings. Its use is obsolete, since this method has already been replaced by flash memory (also called EEPROM).

Why is the BIOS outdated?

BIOS has been around for a long time and has evolved little. Even MS-DOS computers released in the 1980s had a BIOS.

Of course, over time, the BIOS changed and improved. Its extensions were developed, in particular, ACPI, Advanced Configuration and Power Interface (advanced configuration and power management interface). This allowed the BIOS to more easily configure devices and more advanced power management, such as hibernation. But BIOS has not evolved as much as other computer technologies since MS-DOS.

The traditional BIOS still has serious limitations. It can only boot from hard drives with a capacity of no more than 2.1 TB. Nowadays, 3 TB disks are already common, and a computer with BIOS will not boot from them. This is a BIOS MBR limitation.

The BIOS must operate in 16-bit processor mode and only 1 MB of memory is available to it. It has problems initializing multiple devices at the same time, which results in a slow boot process during which all hardware interfaces and devices are initialized.

The BIOS was long overdue for replacement. Intel began working on the Extensible Firmware Interface (EFI) back in 1998. Apple chose EFI, moving to Intel architecture on their Macs in 2006, but other manufacturers did not follow it.

In 2007, Intel, AMD, Microsoft and PC manufacturers agreed on a new specification, the Unified Extensible Firmware Interface (UEFI), a unified extensible firmware interface. This is an industry standard maintained by the UEFI forum and does not depend solely on Intel. UEFI support in Windows appeared with the release of Windows Vista Service Pack 1 and Windows 7. Most computers you can buy today use UEFI instead of BIOS.

How UEFI replaces and improves BIOS


UEFI replaces the traditional BIOS on PCs. There is no way to change the BIOS to UEFI on an existing PC. You need to buy hardware that supports UEFI. Most versions of UEFI support BIOS emulation so you can install and run a legacy OS that expects a BIOS instead of UEFI - so they are backwards compatible.

The new standard bypasses BIOS limitations. UEFI firmware can boot from drives larger than 2.2 TB - the theoretical limit for them is 9.4 zettabytes. This is approximately three times the amount of data contained on the Internet today. UEFI supports such volumes due to the use of GPT partitioning instead of MBR. It also has a standardized boot process and runs EFI executable programs instead of code located in the MBR.

UEFI can operate in 32-bit or 64-bit modes and its address space is larger than that of the BIOS - which means faster booting. This also means that the screens UEFI settings You can make it more beautiful than the BIOS, include graphics and mouse support. But this is optional. Many computers still work with UEFI with text mode, which look and work just like the old BIOS screens.

There are many other features built into UEFI. It supports Secure Boot, in which you can verify that the OS boot has not been modified by any malicious program. It can support network operation, which allows for remote configuration and debugging. With a traditional BIOS, you had to sit directly in front of the computer to set up your computer.

And this is not just a BIOS replacement. UEFI is a small operating system that runs on top of the PC's firmware, so it can do much more than BIOS. It can be stored in flash memory on the motherboard or loaded from a hard drive or network.

Different computers have different interfaces and UEFI properties. It all depends on the computer manufacturer, but the basic capabilities are the same for everyone.

How to Access UEFI Settings on a Modern PC

If you are a regular user, you will not notice the transition to a computer with UEFI. The computer will boot and shut down faster, and you will also have access to disks larger than 2.2 TB.

But the procedure for accessing the settings will be slightly different. To access the UEFI settings screen, you may need a boot boot Windows menu. PC makers didn't want to slow down fast loading computer waiting for a key to be pressed. But we also came across UEFIs in which manufacturers left the ability to enter the settings in the same way as in the BIOS - by pressing a key during boot.

UEFI is a big update, but it happened quietly. Most PC users won't notice it and don't have to worry about their new computer using UEFI instead of the regular BIOS. PCs will simply perform better and support more modern hardware and features.

A more detailed explanation of the differences in boot process UEFI can be read in

In this article we will get acquainted with the concept of UEFI and the use of this technology in Windows 8. What is this technology UEFI? The abbreviation UEFI stands for Unified Extensible Firmware Interface(unified extensible firmware interface). This technology is designed to transform the traditional computer boot system and should replace the outdated system BIOS. However, this is not just modernization old technology, but a fundamentally new approach to the technology of booting a computer and starting the OS. In fact, UEFI has virtually nothing to do with the PC BIOS system.

If BIOS is a code (hard and virtually unchangeable) stitched into a special BIOS chip on the motherboard, then UEFI is a flexible programmable interface located on top of all computer hardware components with their own firmware. The UEFI code (much larger than the BIOS boot code) is located in a special directory /EFI/, which can be stored in a variety of places: from a separate chip on the motherboard, to a partition on the hard drive or network storage. In essence, UEFI is an independent lightweight operating system, which is an interface between the main OS and firmware that controls low-level hardware functions of the equipment, which must correctly initialize the equipment and transfer control to the boot loader of the main (“large”) OS installed on the computer.

UEFI includes hardware testing services, boot and test services, as well as implementations standard protocols interactions (including network ones), device drivers, functional extensions, and even its own EFI shell in which you can run your own EFI applications. Those. already at the UEFI level you can access the Internet, or organize a backup hard drive using a graphical GUI familiar to users.

In the next year or two, the UEFI specification will be used in all new motherboards from leading manufacturers, and finding a new computer with a regular BIOS will become almost impossible. Some of the most popular features of UEFI that can be implemented on a computer running under it are: “secure boot” (), low-level cryptography, network authentication, universal graphics drivers and much more. UEFI supports 32 and 64 bit processors and can be used on systems with Itanium, x86, x64 and ARM processors

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

However, if the use of UEFI in Mac OS X (Bootcamp boot manager) and Linux is quite superficial, in Windows 8 the advantages of the UEFI environment can already be fully used.

By the way, to be able to boot older OSes that only support BIOS, UEFI has a BIOS emulation mode called Compatibility Support Module (CSM).

UEFI and Windows 8 support

What benefits can you get by using UEFI and Windows 8 together?

One of the main advantages is the opportunity secure boot(safe boot) – a technology that allows you to prevent the execution of unwanted programs during computer initialization (safe boot technology in UEFI will be discussed in more detail in a separate article).

Thanks to UEFI, Windows 8 can be installed on disks with a capacity of 3 TB or larger, and, accordingly, booted from these disks. This is due to the transition from the table MBR partitions in (BIOS) to GPT (UEFI).

Using UEFI instead of BIOS is one of the key components that ensures Windows 8 boots quickly (UEFI code runs faster due to the fact that it was written entirely from scratch, without the need to drag along a string of ancient rules and compatibility). In addition, when reading in UEFI, a special EFI I/O block size is used, which allows reading 1 MB of data at a time (in BIOS - 64 KB). In addition, a reduction in startup time is achieved due to the fact that there is no need to search for a bootloader on all devices: the boot disk is assigned in UEFI during the OS installation stage.

So, we noted that Windows 8 supports UEFI boot, however, there are a number of features:

  • The computer must be compatible with UEFI v2.3.1
  • UEFI is only supported in the 64-bit version of Windows 8. 32-bit versions of Windows do not support UEFI features (new computers of this OS will have to run in CSM emulation mode).
  • Windows 8 for ARM (Windows RT) will not run on hardware that does not support UEFI or allows you to disable Secure Boot

In subsequent Windows versions(and the upcoming Windows 8 SP1), the developers plan to introduce many other UEFI features, such as: Rootkit prevention (detection of rootkits during the boot process), Network authentication (boot authentication, especially relevant in remote OS deployment scenarios), etc.

Accessing UEFI Settings from Windows 8

It is worth noting that on new computers with pre-installed Windows 8, which uses UEFI to get into the UEFI setup menu (replacing the old BIOS), the usual method of pressing the Delete or F2 key (or other key specified by the vendor) will not work. Because Windows 8 (especially on an SSD) loads very quickly, it is difficult to press a key during this time to enter the UEFI setup mode. It was written somewhere that Windows 8 on an SSD with UEFI waits only 200ms for a key press. Therefore, there is a procedure for calling the UEFI settings program from the Windows 8 boot menu.

You can get to the Windows 8 boot menu in one of three ways:


After the reboot, the Windows 8 boot menu will automatically open, in which you need to select items Troubleshoot->Advanced options. In the advanced options window there is separate button UEFI Firmware Settings, which allows you to go straight to the computer’s BIOS after restarting the PC (in fact, this is UEFI, the settings in which are equivalent to the traditional BIOS of computers).

Many modern manufacturers of components for personal computers and programs are trying to ensure that their products support the UEFI interface. This software solution should be an excellent alternative to the already familiar BIOS system.

What is the specificity of the subject under consideration? software? What options for using it are possible? And what is UEFI? Let's try to understand this issue.

What is UEFI?

UEFI refers to a special interface that is installed between the operating system installed on a computer and the software that ensures the functioning of various hardware components of the computer. Some call this interface BIOS Uefi. On the one hand, even this name contains a mistake. After all, BIOS operates on completely different principles. UEFI is developed by Intel and BIOS is software supported by various brands. The purpose of BIOS and UEFI is basically the same. But formally the BIOS UEFI combination is incorrect, but at the same time it does not contradict the logic of the software and hardware algorithms for PC control.

Differences between UEFI and BIOS

First of all, you should pay attention to the main thing - the differences between classic UEFI and pure BIOS. UEFI today is positioned as a software solution that is a good alternative to BIOS. Many PC motherboard manufacturers are trying to make their devices support software developed by Intel. The differences between UEFI and BIOS can be easily detected by considering the disadvantages of the second system. The first disadvantage is that the BIOS does not provide the ability to provide full use disk space on large hard drives with a capacity exceeding 2 TB.

This is due to the fact that just a few years ago such hard drive capacities seemed unattainable. Therefore, PC manufacturers did not pay special attention to the corresponding disadvantage of the BIOS system. Today, a hard drive with a capacity of 2 terabytes or more will not surprise anyone. Personal computer manufacturers have already felt the need to switch to UEFI. Considering modern technological trends, this need cannot be called biased.

Another feature of the BIOS is that it supports a limited number of partitions on the hard drive. UEFI has the ability to work with 128 partitions. In structure new development Intel has created a GPT partition table that can take advantage of all the technological benefits of UEFI. Despite all the differences discussed between the new environment and the traditional BIOS system, their main functions are the same. There really aren't that many actual differences between these systems. The only exception is the security algorithm implemented in UEFI. Experts believe that the new platform makes it possible to load operating systems faster. Others believe that this is only relevant for the Windows 8 operating system.

Let's take a closer look at the security system used in UEFI.

UEFI Environment Security Technology

UEFI systems are ahead of BIOS in terms of security. Today, there are unique viruses that have the ability to penetrate into the microcircuit itself, in which the BIOS algorithms are written. As a result, it becomes possible to boot the operating system with extended user rights. It opens ample opportunities for unauthorized access. The new software solution from Intel also implements a secure boot mode, which provides an algorithm called Secure Boot.

This algorithm is based on the use of a special type of keys that are certified by the largest brands in the IT industry. In fact, there are not many such companies today. If we talk about support for the corresponding option by OS manufacturers, today only Microsoft provides it in Windows 8. Also, compatibility with this security algorithm is currently implemented in some versions of Linux.

Benefits of the UEFI system

All of the above disadvantages of BIOS systems can also be considered among the advantages of UEFI. But the new system has a number of the most important advantages. Let's take a closer look at them. Firstly, the system has a simple and intuitive clear interface. UEFI implements mouse support, which is not typical for BIOS. In addition, many versions of UEFI support a Russified interface. The algorithms used in the new software solution make it possible to load the OS much faster than with using BIOS. For example, the Windows 8 operating system on a PC with UEFI with adequate CPU performance and other key components loads within 10 seconds.

Other significant advantages of UEFI include a simpler and more convenient update mechanism compared to BIOS. Another useful option implemented in UEFI is the presence of its own boot manager. It can be used if several operating systems are installed on a personal computer.

The technological advantages of the UEFI software interface are now clear. Today, the most popular manufacturers of hardware components for personal computers are trying to ensure compatibility of hardware with the UEFI system. According to IT experts, the transition to a new system can lead to a new technological trend. For leading software and hardware manufacturers, the capabilities offered by UEFI developer Intel seem very attractive. In addition, UEFI technology options are fully supported by the largest brand in the OS market today.

Secure Boot

Let's take a more detailed look at the benefits of Secure Boot, a security technology supported by the UEFI system. What is the main concept?

Secure Boot is a secure boot protocol designed to protect the system from intrusion malware and viruses. The keys used in this technology must be certified to be fully operational. Today, only a small part of all software brands meet this criterion.

These include Microsoft company, which implemented support for such algorithms in the Windows 8 operating system. In some cases, this circumstance can significantly complicate the process of installing other operating systems on personal computers running the UEFI system. When Windows reinstallation UEFI may still show some loyalty, but only if the version of the operating system being installed is as close as possible to the one installed by the manufacturer.

It should also be noted that some Linux distributions. Even if loading a new operating system is prohibited, the UEFI structure provides the ability to disable the Secure Boot algorithm. Of course, in this case, loading the operating system can no longer be considered safe. Nevertheless, the corresponding option can be activated at any time.

UEFI Compatible Operating Systems

In rare cases, it is possible to install alternative operating systems that support Secure Boot. So, for example, theoretically you can install the Windows 7 operating system on a laptop with UEFI support BIOS. In general, the probability of successful installation of alternative operating systems is low. As noted above, some Linux distributions are UEFI compatible.

Settings Features

Next, we’ll look at the nuances of setting up a new software solution. Interesting options include BIOS emulation. What is it for? In some UEFI versions algorithms have been implemented to ensure PC control in accordance with the mechanisms used by the historical predecessor of UEFI. This mode may be named differently depending on the PC you are using. Typically it is called Launch CSM or Legacy. Installing UEFI in standard boot mode should not pose any difficulties.

Features of UEFI access

Another remarkable fact that cannot be ignored is the huge number of UEFI versions. In personal computers produced by different brands, they can differ significantly. The availability of individual features may also vary from computer to computer. For example, it often happens that when the PC boots, a menu is not displayed through which the user can get to the UEFI settings. In this case, Windows provides the ability to download the necessary options. In the “Options” tab, you need to activate “Special boot options”. After this, you need to restart your computer. Download options will appear on the screen.

There is also an alternative method to provide access to UEFI options. It runs on many personal computers. At the very beginning of loading, you must press Esc. After this, the menu discussed above will open.

Features of working in different modes

Please note that when changing mode UEFI work from regular to Legacy, it is advisable to re-enable the UEFI interface with all options at the first opportunity. Otherwise, the operating system may not start. On many personal computers similar problem does not arise. This is due to the fact that manufacturers implement special algorithms into the management structure that allow the UEFI mode to be automatically activated. Available on some models hybrid mode, with which BIOS modulation is started. Differences in UEFI versions also imply the impossibility disable Secure Boot in normal operation mode.

UEFI bootable flash drives

In some situations, it may be necessary to boot the operating system from a flash drive. The main difficulty here is that flash drives whose format is different from FAT32 are not recognized. There is a solution to this problem. All Windows bootable flash drives are formatted in the NTFS file system by default. UEFI does not recognize this file system. Therefore, the main task is to ensure that the corresponding hardware component is formatted in the FAT32 system. Many IT professionals consider this file system to be outdated. However, the relevance of the corresponding standard can be assessed by its application in UEFI.

Flash drive for booting into UEFI

What needs to be done to ensure that the bootable flash drive is recognized by UEFI without problems? Firstly, it is desirable that the storage capacity be at least 4 GB. Secondly, you need to delete all information from the flash drive. Required component to create bootable flash drive is a distribution of the Windows operating system.

Preparing a flash drive

If all of the above elements are present, you can proceed. The flash drive must be inserted into the USB port of the computer. After that in Windows interface open command line. The user must have administrator rights. Next, run through the command line DISKPART program. Then you need to enter the list disk command.

A list of disks present on your system will be displayed. Find your flash drive in it. Select the disk with the command select disc x, where x is the serial number. To format the selected media, just run the Clean command. Next, you need to make a primary partition on the disk. This can be done using the create partition primary command. By entering the active command this section must be made active. After this, the list of partitions can be displayed on the screen by entering the list volume command.

We select the partition we need using the select volume x command, where x is the serial number of the partition. To format it as FAT32, enter format command fs=fat 32. Now you need to assign a letter to the flash drive. This is done using the assign command. You can then exit the command line.

Recording a distribution

After completing all the steps described above, you can copy the Windows distribution kit to a flash drive.