What is the difference between uefi and bios. What is an EFI system or UEFI partition? Computer assistance at Serty There is no legacy uefi option in the BIOS

UEFI (Unified Extensible Firmware Interface) technology, like BIOS, is a computer firmware interface that provides communication between it and the operating system. Like BIOS, the UEFI interface (also referred to in Russian-language computer journalism as UEFI) is used to initialize the computer's hardware components and start the operating system stored on the hard drive.

UEFI positioning scheme in the generalized structure of the interaction of PC components.

The BIOS reads information from the first sector of the hard drive, which contains the master boot record (MBR), and selects the boot device where the operating system resides. Because the BIOS is a very old system, dating back to the mid-1970s, it still runs in 16-bit mode. This circumstance limits the amount of information that can be read from the system ROM (computer read-only memory).

UEFI performs the same task but does it in a slightly different way. It stores all information about the initialization and booting of the system in a special file located on the hard disk in a special section ESP (EFI System Partition). In addition, ESP contains boot programs for the operating system installed on the computer.

The process of booting a computer based on UEFI and emulating a traditional Legacy BIOS

UEFI is intended to be a complete replacement for the BIOS in the future and offers many new features and improvements that cannot be implemented in the BIOS:

1. No restrictions on the volume of sections and their number. BIOS uses the Master Boot Record (MBR) to store information about the hard disk, while UEFI uses the so-called GPT (GUID partition table). The main difference between them is that the MBR uses 32-bit elements, which allows the system to have only 4 physical disk partitions, and each partition can be no more than 2 terabytes in size. As for GPT, it has 64-bit elements, which allows the system to have up to 128 partitions up to a zettabyte (1021 bytes) in size.
2. Speed ​​and performance. Since the UEFI technology is platform independent, it can reduce boot time and increase the speed of the computer, especially if large hard drives are installed in the system.
3. Security. The biggest advantage of UEFI over BIOS is security. It is implemented using Secure Boot technology (secure startup) supported by the Windows 8 operating system. Since Secure Boot has the ability to request a digital signature from boot programs, the UEFI interface allows only authenticated drivers and services to be used during boot. Secure Boot controls the boot process until the operating system is fully loaded. This ensures that no malware enters the computer during boot.
4. Backward compatibility. For backward compatibility, most UEFI implementations on PC architectures also support Legacy BIOS mode for MBR disks. To do this, UEFI has a CSM (Compatibility Support Module, Compatibility Support Module) function. In the case of an MBR disk, booting is performed in the same mode as in BIOS-based systems. It is also possible to boot BIOS-based systems from disks that have GPT.
5. Network boot support. UEFI can boot over the network using Preboot eXecution Environment (PXE) technology. This technology supports major network protocols such as IPv4 and IPv6, UDP, DHCP, and TFTP. Booting from boot images stored in network storages is also supported.
6. Download manager. The UEFI standard defines the boot manager as a tool designed to boot the operating system and all necessary drivers. Operating system loaders are stored in files that can be accessed by the firmware. UEFI supports FAT32 file systems, as well as FAT16 and FAT12 for removable media. UEFI is independent of boot sectors, although ESP allocates space for them for backwards compatibility. Bootloaders are automatically detected by UEFI software, allowing booting from removable media.

History of technology

EFI BIOS technology was originally developed by Intel. The UEFI standard is currently being developed by the UEFI Forum.

The initial motivation for the development of EFI was BIOS limitations, such as 16-bit processor mode, 1 MB of addressable memory space, which was unacceptable for serious server platforms such as Itanium. An attempt to fix these problems was originally called the Intel Boot Initiative in 1998 and later renamed EFI.

In 2005, Intel put the EFI standard on hold at version 1.10 and handed it over to the Unified EFI Forum, which evolved the standard into a UEFI version. At the same time, the owner of the original EFI BIOS standard continues to be Intel, which issues licenses for products based on EFI technology. UEFI 2.1 was released in January 2007 and adds data encryption, network authentication, and User Interface Architecture technology. The current version of the UEFI 2.4 standard was adopted in July 2013.

Criticism of UEFI

UEFI is sometimes criticized, in particular by advocates of information rights. For example, computer expert Ronald G. Munnich, one of the developers of the alternative open source boot technology Coreboot, denounces EFI as an attempt to limit a user's ability to fully control their computer. In addition, he believes that this technology does not solve any of the long-standing problems of the traditional BIOS, in particular, the need for two drivers - one for the firmware, the other for the operating system.

Conclusion

UEFI is a technology that has both many advantages and disadvantages. To date, it is not yet ubiquitous and is not supported by all computers and other devices. Having a boot manager built into UEFI means that there is no need for separate bootloaders. In addition, this technology can work in conjunction with the BIOS (in compatibility mode - Legacy BIOS) and independently. At the same time, the BIOS can still be used where it is not necessary to store large amounts of data, and the security problem is not extremely relevant.

As soon as we turn on the computer, it immediately starts running a miniature operating system, which we know as the BIOS. It deals with testing devices, memory, loading operating systems, and allocating hardware resources. Many of the features in this suite of programs (usually around 256-512 KB in size) make it possible to support older operating systems like MS-DOS, giving them a lot of options. Since the days of the PC/AT-8086, the BIOS has changed very little, and by the time the first Pentiums were launched, its development had almost stopped. Actually, there was nothing to change in it, except for the dual BIOS, support for network tools and the possibility of flashing. But there were a lot of minuses: the starting entry into the real mode of the processor, 16-bit addressing and 1 MB of available memory, the inability to have a "repair" console. And, of course, the eternal problem of supporting hard drives. Even now, drives up to 2.2 TB are guaranteed to be supported, no more.

Back in 2005, Intel decided to change the BIOS to EFI / UEFI (Unified Extensible Firmware Interface). The EFI system is a more advanced base operating system. On some Unix and Windows platforms, UEFI has been around for a long time, but the mass transition has not yet happened, despite good intentions. And they are:

• The presence of the notorious console for repairing system parameters and installing the OS;
• The EFI section makes it possible to perform some actions without loading the OS (watching movies, starting music);
• Internet access and, therefore, the presence of installed network drivers, TCP / IP stack, etc.);
• The presence of a graphical mode and user scripts;
• Support for giant disks;
• UEFI storage on new format partitions (GPT);
• Full support for all hardware from launch.

UEFI can use a generic executing machine like the JVM to consume hardware-independent code, and this opens up vast possibilities for creating "bootable" software.

There is also criticism of this technology. In particular, its implementation can lead to cutting off new players from the operating system market: there will always be some technological loophole in the code for this. Like, for example, the inability to boot Windows 98 from modern BIOSes. But, worse, you will have to forget about the millions of MS-DOS programs and other systems that relied on BIOS functions for their work. Perhaps they will still be emulated, but there are doubts about this. And among them, there are probably important programs that there will be no one to rewrite. However, all these issues are solvable - at least through virtual operating systems. But the fact that new types of viruses will appear is certain, and we will be able to see this pretty soon.

Hello dear readers! Today we will talk about one topic that is difficult at first glance, which will sound like this: UEFI Boot - what is it and how to disable UEFI in BIOS.

Of course, for an ordinary user, all these names and abbreviations do not mean anything, but nevertheless, when buying modern desktop computers and laptops, you will still come face to face with these concepts.

Yes, friends, this is the same settings section on a blue background, which you can enter at the very beginning when you turn on the computer. Here's a picture to refresh your memory:

Many more enthusiasts tried to play with the voltage and frequency of the main processor here in order to increase the power of their machine. So, the BIOS microprogram was replaced by another, more modern one.

And as you already understood, it is called UEFI. Among the new innovations, it can be noted support for high screen resolutions, very large disks and work with the mouse.

If you read all the lines above and did not understand anything at all, then watch a short video to reinforce the topic:

So, it should definitely be said that a full-fledged UEFI system is not yet implemented in all modern computers. But some of its new features, hitherto unseen, have been successfully implemented in the old BIOS shell.

And one of them, the so-called UEFI Boot (full name Secure Boot). The meaning of its work is to prevent the substitution of the system boot source, thereby reducing the use of unlicensed software.

That is, it turns out such a picture that now we will not be able to boot, for example, from a flash drive or a third-party disk. Indeed, in this situation, they simply will not be in the list of available devices:

But in fact, this problem can be solved very easily. To do this, you need to make a couple of settings and that's it. So let's get to work. So, enough of the theory.

And in order to disable UEFI functions in BIOS, you must immediately enter it. As mentioned above, for this you need to press a certain key combination immediately after turning on the computer.

Thus, we have disabled the main UEFI protection function from third-party bootloaders. Then you should go to the "Boot" section and set the parameters as in the screenshot below:

After that, we should have a list of available devices. Now by changing their position in the list, you can manipulate the download sources. Again, using the author's example, this can be done with a keyboard shortcut Fn+F5/F6:

Well, after all the parameters entered, it remains only to save the changes. This is done in the "Exit" menu by selecting the "Exit Saving Changes" item:

That's all, my friends, now you know for sure the answer to the question: UEFI Boot - what is it and how to disable UEFI in BIOS. If you still have questions, feel free to ask them in the comments.

Well, if you suddenly want to learn much about the UEFI BIOS, then watch a short video where this topic is covered more widely.

What is a BIOS?
BIOS (Basi Input / Output System) or basic input / output system - a set of firmware that provides the initial start-up of the computer and initialization of the equipment, recorded in a special chip on the motherboard. Provides an API for the operating system to access all available hardware and connected devices. The main BIOS manufacturers are: AMI (American Megatrends), Award Software and Phoenix Technologies.

When the computer starts, the BIOS checks the critical system components - POST, i.e. Power-on self-test. If a malfunction or any problem is detected, the BIOS will display information in the form of a message or, more often, beep. If everything is in order, you will most likely hear 1 short beep and the download will continue.

Introduction to UEFI

Unified Extensible Firmware Interface - A standardized extensible firmware interface. The underlay interface between computer components and the operating system. Essentially the same BIOS, only slightly improved. Does everything the same as the standard BIOS, ie. performs a check, initializes the hardware, searches for the bootloader, and transfers control to the OS. It is also endowed with a number of innovations, more on that below.

The main advantages of UEFI over BIOS:
1) It takes much less time to boot, which is achieved using parallel initialization, unlike the BIOS, which initializes all components sequentially. You can see the loading scheme in the diagram below. It is also noteworthy that the operating system will be able to use uefi, and not load its own. For example, if you are undemanding to the graphics subsystem, then you can not download, and therefore do not install new drivers, but use the drivers offered by UEFI.

2) Another important advantage is that you can boot from disks larger than 2 TB. The fact is that the BIOS used MBR (Master Boot Record) for booting - the main boot record that can only address 2 TB of space, while UEFI uses GPT (Guid Partition Table) - this is another standard for the format for placing partitions on a physical hard drive, which allows you to address as many as 9 ST (Zettabytes).
3) UEFI has also acquired a graphical interface with mouse support, for whom this is a plus, and for whom it is a minus. Some built-in programs appeared, for example, a browser. Thus, uefi began to represent not only an interface between the operating system and hardware components, but also a kind of .
4) Support for cryptography and other protection methods. There are many nuances in this regard, we will not go into details.
There is nothing radically new, some improvements and improvements, but gradually uefi will completely replace bios.

Most modern computers, instead of the usual primary input / output system, are equipped with the latest control tool, called UEFI. What it is, not yet known to all users of computers and laptops. In the following, some important aspects related to this development will be considered. In addition, we will briefly touch on issues related to installing operating systems through this interface using bootable USB media, and also determine how to disable UEFI if using this system is inappropriate for some reason. But first, let's look at the primary understanding of what kind of system it is.

UEFI: what is it?

Many users are accustomed to the fact that in order to configure the primary parameters of the computer system, even before the OS starts, you need to use the BIOS. In fact, the UEFI mode, which is used instead of the BIOS, is almost the same, but the system itself is built on the basis of a graphical interface.

When loading this system, which, by the way, many call a kind of mini-OS, the fact of mouse support and the ability to set the regional language for the interface immediately attracts attention. Going further, you will notice that, unlike the BIOS, UEFI can work with support for network devices and display the optimal operating modes for some components of the installed hardware.

Some call this system a dual term - BIOS UEFI. Although this does not contradict the logic of software and hardware, nevertheless, such a definition is somewhat incorrect. Firstly, UEFI is developed by Intel Corporation, and BIOS systems are developed by many other brands, although they do not differ radically from each other. Secondly, BIOS and UEFI operate on slightly different principles.

The main differences between UEFI and BIOS

Now another look at UEFI. What this is in a clearer sense can be determined by finding out the differences between this system and the BIOS. It is believed that UEFI is positioned as a kind of alternative to the BIOS, the support of which is now announced by many motherboard manufacturers. But the differences are best considered on the basis of the minuses of obsolete BIOS systems.

The very first difference is that the BIOS's primary input/output systems do not allow you to work correctly with hard drives that are 2 TB or more, which means that the system does not have the ability to fully utilize the disk space.

The second point is that BIOS systems are limited to working with disk partitions, while UEFI supports up to 128 partitions, which is made possible thanks to the GPT partition table.

Finally, UEFI implements completely new security algorithms, which completely eliminates the bootloader substitution at the start of the main OS, preventing even the effects of viruses and malicious codes, and provides a choice of the bootable operating system without using specific tools inside the bootloaders of the OS itself.

A bit of history

This is the UEFI system. What it is is already somewhat clear. Now let's see where it all began. It is a mistake to think that UEFI is a relatively recent development.

The creation of UEFI and the universal interface began in the early 90s. As it turned out then, for Intel server platforms, the capabilities of standard BIOS systems were not enough. Therefore, a completely new technology was developed, which was first implemented in the Intel-HP Itanium platform. At first it was called the Intel Boot Initiative, and was soon renamed the Extensible Firmware Interface or EFI.

The first modification of version 1.02 was introduced in 2000, version 1.10 was released in 2002, and since 2005, the then-formed alliance of several companies, called the Unified EFI Forum, began to develop the new development, after which the system itself became known as UEFI. Today, among the developers, you can meet many famous brands, such as Intel, Apple, AMD, Dell, American Megatrends, Microsoft, Lenovo, Phoenix Technologies, Insyde Software, etc.

UEFI security system

Separately, it is worth dwelling on the mechanisms of the protection system. If anyone does not know, today there is a special class of viruses that are capable of writing their own malicious codes when embedded in the microcircuit itself, changing the initial algorithms of the I / O system, which leads to the possibility of launching the main operating system with extended management rights. This is how viruses can gain unauthorized access to all OS components and controls, not to mention user information. Installing UEFI completely eliminates the occurrence of such situations by implementing a secure boot mode called Secure Boot.

Without going into technical aspects, it is only worth noting that the security algorithm itself (secure boot) is based on the use of special certified keys supported by some well-known corporations. But, for some reason, it is believed that this option is supported only by Windows 8 and higher operating systems, as well as some modifications of Linux.

Why is UEFI better than BIOS?

The fact that UEFI surpasses BIOS in its capabilities is noted by all experts. The fact is that the new development allows you to solve some problems even without loading the operating system, the start of which, by the way, when the optimal mode of operation of the main "iron" components such as a processor or RAM is set, is much faster. According to some reports, the same Windows 8 boots within 10 seconds (however, this indicator is clearly conditional, since you need to take into account the general hardware configuration).

However, UEFI support also has a number of undeniable advantages, among which are the following:

• simple intuitive interface;
• support for regional languages ​​and mouse control;
• work with disks 2 TB and above;
• the presence of its own bootloader;
• the ability to work on processors with x86, x64 and ARM architecture;
• the ability to connect to local and virtual networks with Internet access;
• the presence of its own system of protection against the penetration of malicious codes and viruses;
• simplified update.

Supported operating systems

Unfortunately, not all operating systems support UEFI. As already mentioned, basically such support is declared for some modifications of Linux and Windows, starting from the eighth version.

Theoretically, you can install Windows 7 (UEFI recognizes the installation distribution). But no one will give a full guarantee that the installation will be completed successfully. In addition, if you use Windows 7, the UEFI interface and all the related features of the new system will simply remain unclaimed (and often unavailable). Thus, it is not advisable to install this particular system on a computer or laptop with UEFI support.

Features of Secure Boot Boot Mode

As mentioned above, the secure boot system is based on the use of certified keys to prevent viruses from entering. But such certification is supported by a limited number of developers.

When the operating system is reinstalled via UEFI, there will be no problems provided that the installed system is as close as possible to the original installed earlier. Otherwise (which is not uncommon), a ban on installation may be issued. However, there is also a way out, since the Secure Boot mode itself can be disabled in the settings. This will be discussed separately.

Nuances of access and UEFI settings

There are quite a lot of UEFI versions themselves, and different computer equipment manufacturers install their own options for starting the primary system. But sometimes, when trying to access the interface, problems can arise, such as the main settings menu is not displayed.

In principle, for most computers and laptops with UEFI support, you can use a universal solution - pressing the Esc key when logging in. If this option does not work, you can use the native Windows tools.

To do this, you need to enter the settings section, select the recovery menu and click on the “restart now” link in the line of special boot options, after which several start options will appear on the screen.

As for the basic settings, they practically do not differ from standard BIOS systems. Separately, we can note the presence of the BIOS emulator mode, which in most cases can be called either Legacy or Launch CSM.

In addition, it is worth paying attention to the fact that when switching to Legacy mode, at the first opportunity, you should re-enable the UEFI settings, since the operating system may not boot. By the way, the differences between different versions of UEFI are that some provide a hybrid launch mode for either the BIOS emulator or UEFI, while others do not have such an opportunity when working in normal mode. Sometimes this may also apply to the inability to disable Secure Boot.

UEFI bootable flash drive: prerequisites for creating

Now let's see how to create a bootable USB drive for the subsequent installation of the operating system using the UEFI interface. The first and most important condition is that the UEFI bootable USB flash drive must have a capacity of at least 4 GB.

The second problem concerns the file system. As a rule, Windows systems format removable drives using NTFS by default. But UEFI USB drives with file systems other than FAT32 are not recognized. Thus, at the first stage, formatting should be done using this parameter.

Formatting and burning a distribution image

Now the most important moment. Formatting is best done from the command line (cmd) launched with administrator rights.

In it, the diskpart command is first entered, after which the list disk line is written, and the desired device is selected with the select disk N command, where N is the serial number of the USB flash drive.

Next, the clean line is used for complete cleaning, and then the primary partition is created by the create partition primary command, which is activated by the active command. After that, the list volume line is used, the flash drive is selected with the select volume N line (the above partition serial number), and then the start of the formatting process is activated with the format fs=fat32 command. At the end of the process, the assign command can assign a specific character to the media.

After that, an image of the future system is written to the media (you can use either regular copying or creating a bootable USB flash drive in programs like UltraISO). When rebooting, the desired media is selected, and the OS is installed.

Sometimes a message may appear stating that installation to the selected MBR partition is not possible. In this case, you need to go to the UEFI boot priority settings. There will be displayed not one, but two flash drives. The download must be started from the device in the name of which there is no EFI abbreviation. This eliminates the need to convert MBR to GPT.

UEFI firmware update

As it turns out, updating the UEFI firmware is much easier than performing similar operations for the BIOS.

It is enough just to find and download the latest version on the official website of the developer, and then run the downloaded file as an administrator in a Windows environment. The update process will take place after the system is rebooted without user intervention.

Disable UEFI

Finally, let's see how to disable UEFI, for example, for cases where booting from removable media is impossible only because the device itself is not supported.

First you need to go to the Security section and disable the Secure Boot mode (if possible) by setting the Disabled parameter for it. After that, in the Boot boot menu, in the Boot Priority priority line, set the Legacy First value. Next, from the list, you need to select the device that will be the first to boot (hard drive) and exit the settings, after saving the changes (Exit Saving Changes). The procedure is completely similar to the BIOS settings. Instead of menu commands, you can use the F10 key.

Brief summary

That's briefly all about the UEFI systems that have replaced the BIOS. They have a lot of advantages, as you can see. Many users are especially pleased with the graphical interface with native language support and the ability to control using the mouse. However, fans of the seventh version of Windows will have to disappoint. Its installation on UEFI-enabled computer systems looks not only impractical, but sometimes it becomes completely impossible. Otherwise, using UEFI looks very simple, not to mention some additional features that can be used even without loading the operating system.