The massive transition to UEFI (Unified Extensible Firmware Interface) has already begun. Microsoft requires this interface to be used on all computers that will ship with Windows 8. More precisely, we are talking about UEFI with Secure Boot. At the same time, only the "eight" can work without problems on such PCs: neither Windows XP, nor the "seven" can be installed on a UEFI machine without additional manipulations. You won't be able to boot from a Linux Live or Windows flash drive either. What exactly can happen if you try to start from the installation flash drive on a laptop Sony VAIO shown in the picture above. And the problems with UEFI don't end there. Each manufacturer of hardware components configures UEFI at their discretion, thereby creating unnecessary difficulties for the user. Lenovo's IdeaPad laptop couldn't recognize the same flash drive as bootable media at all. At the same time, Lenovo has nothing to blame: the fact is that the bootable USB flash drive is formatted in the NTFS file system, and UEFI does not support booting from such media. If you connect the same drive to your HP EliteBook, it will boot up without issue and allow you to install Windows. The problem is that all the data on the EliteBook drive would be deleted after installation.
Each configures differently
Are you confused? No wonder: UEFI with the Secure Boot function sets new rules for installing and booting operating systems, and hardware manufacturers interpret these rules in their own way, which creates additional difficulties for the user. Therefore, within the framework of this article, we have set ourselves the goal of eliminating the confusion around UEFI. Using laptops from major manufacturers as an example, we will tell you how UEFI works, what role is assigned to the Secure Boot function, how to bypass the "pitfalls" set by the new interface, and what is needed in order to use bootable flash drives without fear of any destructive consequences.
How UEFI works
UEFI boots strictly according to the established rules. If the OS does not support UEFI, BIOS emulation mode is activated. The BIOS-based PC boot process is quite simple: after pressing the power button, the BIOS starts, which checks the hardware status and loads the micro software- simple drivers for individual hardware components. The BIOS then searches for the OS bootloader and activates it. That, in turn, loads the operating system or displays a list of available operating systems.
UEFI-based computers boot in the same way only until they look for boot options. After that, everything happens differently. UEFI has its own OS bootloader with integrated startup managers for installed systems. For it, a small partition (100-250 MB) is created on the disk, formatted in the FAT32 file system, which is called Extensible Firmware Interface System Partition ( system partition Extensible Firmware Interface, ESP). It contains drivers for hardware components that can be accessed by the running operating system... The general rule of thumb is that with the exception of DVDs, UEFI can only boot from media formatted with the FAT32 file system.
UEFI is a complex mechanism
ESP has its advantages: thanks to the UEFI drivers and the OS bootloader, Windows starts faster and responds more adequately to critical errors drivers. But the UEFI interface also imposes restrictions: it allows you to install the OS only on hard drives that are marked up according to the GPT standard. The latter is not supported by any BIOS version, since, unlike the traditional partitioning scheme (MBR), it uses 64-bit sector addresses. Besides Windows 8, only 64-bit versions support UEFI Windows Vista and 7, as well as Linux with kernel 3.2 and higher. Moreover, for PCs certified to work with the G8, Microsoft directs the use of the Secure Boot option. In this mode, UEFI only launches approved OS loaders that contain drivers with digitally signed Microsoft.
Along with Windows 8, only the Shim (Linux) boot loader has drivers with the signatures required for Secure Boot. They are absent in other operating systems. Therefore, if you want to install Windows 7 or Vista on such a computer in addition to the G8, you must open the UEFI menu and disable Secure Boot. If you choose a non-UEFI-compatible OS as your second OS, you will need to use the Compatibility Support Module (CSM), which can be enabled in UEFI. Unfortunately, manufacturers use different versions of UEFI, and sometimes it is difficult to figure out how to disable Secure Boot and switch to BIOS emulation mode. We will consider these questions further.
UEFI PC Boot Process
Depending on the configuration, UEFI either boots the computer on its own or enters the standard BIOS emulation mode. Only then does the Windows boot manager start.
Installing Windows on a PC with UEFI and Secure Boot
On Windows 8 PCs with UEFI Secure Boot, other OS versions may only be installed under certain conditions. The user should select the correct boot mode in advance and prepare the installation flash drive accordingly.
Enabling BIOS emulation mode
A complete mess: the way to enter BIOS emulation mode depends on the UEFI version. On Sony VAIO (1) you need to activate the "Legasy" option, on ASUS Zenbook (2) - "Launch CSM".
Configuring UEFI
Each manufacturer uses its own version of UEFI in laptops and ultrabooks. However, it does not provide access to all the necessary functions. Often, when a PC or laptop is booted, the name of the button is not displayed on the display, with which you can call the UEFI settings menu. We propose to proceed as follows: in the Metro interface, go to the Options | Changing computer settings "on the sidebar and activate the item" General | Special download options ”. After restarting, the OS boot manager will appear, which will allow you to open the UEFI menu. The exception is HP's UEFI, which does not have this option. The following will help here: while loading, hold down the "Esc" key. In any case, you must first inquire which button allows you to enter the UEFI menu. If you change the boot mode to CSM or Legasy BIOS in order to boot from an emergency flash drive, you must switch from CSM to UEFI again after the restore operation, otherwise Windows 8 will not start. But there are exceptions here: Aptio Setup Utility on ASUS computers activates UEFI automatically if there is no BIOS compatible bootable media, so you just need to disconnect the USB flash drive.
Disabling Secure Boot will be required if, in addition to the G8, you want to install a 64-bit version of Windows Vista or 7. Sometimes the so-called hybrid mode is supported, as in devices from HP, in which UEFI can boot from all bootable media and, if necessary switch to BIOS mode. In the widespread version of UEFI InsydeH2O, this depends on whether the laptop manufacturer has provided the option to disable Secure Boot or not. V Acer aspire S7, this function is not available, and to deactivate it, you need to switch from UEFI to BIOS mode and vice versa.
Difficulty with recovery
With the advent of UEFI, manufacturers have changed the way they deal with OS recovery. The Alt + F10 keyboard shortcut, which was previously used, for example, in Acer models, no longer works or is assigned to other functions. And the "F9" button loads on the new Zenbook not the ASUS Preload Wizard, but the program Windows recovery 8 with an extended boot menu.
VAIO Care recovery mode in Sony notebooks can be accessed from a similar menu by selecting Control Panel | Troubleshooting | Recovery". But if you start the OS boot manager and select "Diagnostics | Restore "or" Restore to its original state ", the device will ask you to insert the original Windows disk 8, which is not included in the package. On Acer models, the backup is performed using the preinstalled Windows program, and the restore from the backup is carried out from an external USB drive. However, you must first go to the UEFI menu and specify such a disk as bootable.
Go to the UEFI menu from Windows
If the function is activated Windows startup 8 with advanced settings, then by selecting the item "Diagnostics" (1) and " Extra options”(2), you can access the UEFI Firmware Settings menu (3).
Useful UEFI features
Each laptop manufacturer uses a different version of the UEFI interface and implements it in the system in accordance with their ideas. From the table by model, you can find out where the main features of UEFI are.
Solution to the problem: disabling Secure Boot
In some cases, Secure Boot cannot be deactivated directly. In the Acer Aspire S7, for example, this function is not available. But if you switch to "Legasy BIOS" (1) and back again (2), Secure Boot will be disabled.
Anything is possible in hybrid mode
The HP version of the UEFI interface has support for hybrid mode, in which, depending on the bootable media, one of two modes is launched - either UEFI or CSM. In this case, the Secure Boot function is disabled automatically.
Launch from a flash drive
Old flash media for emergency boot and recovery works only in BIOS mode... We will make them UEFI compliant.
USB sticks in recent times are increasingly used as bootable media for Windows recovery or installation. This is due to the fact that in modern laptops very rarely installed optical drives... If you have studied the UEFI settings on your computer, it is recommended that you upgrade your flash drives as well. With the advent of UEFI, all available bootable flash drives can no longer be used in the usual way. For example, if you created a bootable USB media in the UNetbootin program, you will need to start the PC in CSM mode. The same applies to all old flash drives, since the developers Linux distributions Live (for example, GParted) only in the latest, most recent versions of their applications began to add a bootloader with UEFI support and the Secure Boot function.
The simplest is the way in which Secure Boot is disabled in UEFI, then using free software Rufus creates a UEFI-compatible flash drive, after which it is copied to it latest version GParted.
Microsoft program is outdated
Slightly different rules apply to Windows bootable USB media. For UEFI compatibility, they must be formatted with the FAT32 file system. Many users even for Windows 8 create boot drives on flash drives formatted using a program from Microsoft, which is part of the "seven". but this application by default formats the drive in the NTFS file system, as a result of which the existing system on the media cannot subsequently be installed on a computer with UEFI. To avoid waiting for an updated program from Microsoft to release, you can manually create a bootable device. To do this, first format the USB stick using a free utility. Then open the ISO image in Windows 8 and copy the files it contains to the media.
But in order for a UEFI-compatible flash drive with 64-bit Windows 7 to boot without any problems, you will need to copy the UEFI bootloader to the desired directory on the flash drive. To do this, using the free 7-Zip archiver, find in ISO image which contains the installation Windows files 7, in the Sources folder, the Install.wim archive file and open it. After that, copy the bootmgfw.efi file from the 1 \ Windows \ Boot \ EFI directory. Then save it to a flash drive in the efi \ boot directory and rename it to bootx64.efi. After that, it will be possible to work with the USB-drive in UEFI mode, and you will be able to install Windows 7 from it without any problems.
Creating bootable USB sticks based on Live systems
For UEFI compatibility, flash drives must be formatted in FAT32. For example, UNetbootin (1) creates bootable media based on Linux Live distributions by formatting them to FAT. However, the Rufus (2) utility offers a more correct option.
UEFI PC Recovery Flash Drive
Flash drives based on fresh Live systems, such as GParted, are capable of accessing UEFI PCs without problems, as their built-in tools - such as GPart (1) and TestDisk (2) - can work with GPT partitions.
Formatting bootable flash drive with windows
Windows 7 64-bit can also be installed on UEFI PCs. If you want to perform this operation from a USB drive, you must format it using the Windows program DiskPart in the FAT32 file system and make it bootable.
Removing the UEFI Boot Loader
A UEFI-compatible flash drive running Windows 7 additionally needs a UEFI bootloader - bootmgfw.efi. It must be manually copied from the install.wim archive to a USB flash drive using the 7-Zip program or any other archiver.
A source
Majority modern computers instead of the usual primary I / O system, it is equipped with the latest management tool called UEFI. Not all computer and laptop users still know what it is. Some of the important aspects associated with this development will be discussed below. In addition, we will briefly touch on the issues related to installing operating systems through this interface using bootable USB media, and also determine how to disable UEFI if the use of this system for some reason is impractical. But first, let's figure out the primary understanding of what kind of system it is.
UEFI: what is it?
Many users are accustomed to the fact that to configure the primary parameters of a computer system, even before starting the OS, you need to use the BIOS. In fact, the UEFI mode, which is used instead of 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, immediately draws attention to the fact of mouse support and the ability to install a regional language for the interface. If you go further, you will notice that, unlike BIOS, UEFI can work with support network devices and display the optimal modes of operation of some components of the installed equipment.
Some people 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 the development of Intel, and BIOS systems are developed by many other brands, although they are not fundamentally different from each other. Secondly, BIOS and UEFI operate on slightly different principles.
The main differences between UEFI and BIOS
Now for another look at UEFI. What is this 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 BIOS, support for which is today announced by many motherboard manufacturers. But the differences are best viewed on the basis of the disadvantages of outdated BIOS systems.
The very first difference is that the primary input / output systems of the BIOS do not allow to work correctly with hard disks, the volume of which is 2 TB or more, which is that the system does not have the ability to fully use the disk space.
The second point concerns the fact that for BIOS systems there is a restriction on working with disk partitions, while UEFI supports up to 128 partitions, which becomes possible due to the presence of a GPT standard partition table.
Finally, completely new security algorithms are implemented in UEFI, which completely excludes the substitution of the bootloader at the start of the main OS, preventing even the effects of viruses and malicious codes, and provides a choice of the operating system to be loaded without using specific tools inside the bootloaders of the OS themselves.
A bit of history
This is the UEFI system. What it is is already a little clear. Now let's see how 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 the server Intel platforms the capabilities of standard BIOS systems were not enough. Therefore, it was developed completely new technology, which was first introduced in the Intel-HP Itanium platform. At first it was called Intel Boot Initiative, and soon it was renamed Extensible Firmware Interface or EFI.
The first modification of version 1.02 was presented in 2000, version 1.10 was released in 2002, and since 2005, an alliance of several companies formed at that time, called the Unified EFI Forum, began to be engaged in new development, after which the system itself became known as UEFI. Today, among the developers, you can find 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 able to prescribe their own malicious codes when introduced into the microcircuit itself, changing the initial algorithms of the input / output system, which leads to the emergence of the possibility of starting 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 due to the implementation of the mode secure boot called Secure Boot.
Without going into technical aspects, it is worth noting only that the protection (secure boot) algorithm itself is based on the use of special certified keys supported by some well-known corporations. But, as for some reason, it is believed that this option is supported only by operating Windows systems 8 and higher, as well as some Linux modifications.
Why is UEFI better than BIOS?
The fact that UEFI surpasses BIOS in its capabilities is noted by all experts. The fact is that new development allows you to solve some tasks even without loading the operating system, the start of which, by the way, when the optimal operating mode of the main "hardware" components is set, such as a processor or random access memory is much faster. According to some reports, the same Windows 8 boots within 10 seconds (although this figure 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 controls;
- work with disks 2 TB and higher;
- the presence of its own bootloader;
- the ability to work on the basis of 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, this support is mainly stated for some modifications of Linux and Windows, starting with the eighth version.
Theoretically, you can install Windows 7 as well (the UEFI installation distribution will recognize it). But no one will give a full guarantee that the installation will be completed successfully. Moreover, in the case using windows 7 UEFI interface and all related features new system will simply remain unclaimed (and often inaccessible). Thus, it is impractical to install this particular system on a computer or laptop with UEFI support.
Features of the 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 re-installed via UEFI, there will be no problems, provided that the installed system is close to the original previously installed to the maximum. Otherwise (which is not uncommon), an installation ban 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 few versions of UEFI themselves, and different manufacturers of computer equipment set their own options for starting the primary system. But sometimes, when trying to access the interface, problems may arise, such as the main settings menu not being displayed.
Basically, for most computers and laptops with UEFI support, you can use a universal solution - pressing the Esc key at login. If this option does not work, you can also use the native Windows tools.
To do this, you need to enter the parameters section, select the recovery menu and click on the "restart now" link in the special boot options line, after which several start options will appear on the screen.
As for the basic settings, from standard systems BIOS, they practically do not differ. 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, you should pay attention to the fact that when switching to the Legacy operating 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 in some there is a hybrid mode of launching either a BIOS emulator or UEFI, while in others there is no such possibility during normal operation. Sometimes this may also concern the inability to disable Secure Boot.
Bootable UEFI flash drive: prerequisites for creating
Now let's see how to create a bootable USB media for the subsequent installation of the operating system using the UEFI interface. The first and foremost condition is that the bootable UEFI flash drive must have a volume of at least 4 GB.
The second problem concerns the file system. Typically, Windows systems format removable drives using NTFS by default. But UEFI USB drives with file systems other than FAT32 does not recognize. Thus, at the first stage, formatting should be performed using this parameter.
Formatting and burning the distribution image
Now the most important point. Formatting is best done from the command line (cmd) running with administrator rights.
In it, the diskpart command is first entered, after which the list disk line is written, and with the select disk N command, where N is the serial number of the USB flash drive, the desired device is selected.
Next, the clean line is used for a complete cleanup, and then the create partition primary command creates a primary partition, which is activated by the active command. After that, the list volume line is used, the select volume N line (the above sequence number of the partition) selects the flash drive, and then the format fs = fat32 command activates the start of the formatting process. At the end of the process with the assign command, you can assign a specific letter to the medium.
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 you reboot, 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. Not one, but two flash drives will be displayed there. The boot must be started from the device whose name does not contain the abbreviation EFI. 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 developer's official website, and then run the downloaded file as administrator in Windows environment... The update process will take place after rebooting the system without user intervention.
Disable UEFI
Finally, let's see how to disable UEFI, for example, for cases where booting from removable media is impossible just 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 boot menu Boot in the Boot Priority line should be set to Legacy First. Next, from the list, you need to select the device that will be the first to boot ( HDD) and exit the settings after saving the changes (Exit Saving Changes). The procedure is completely similar to BIOS settings. You can use the F10 key instead of menu commands.
Brief summary
Here's all in a nutshell about UEFI systems that replaced BIOS. As you can see, they have a lot of advantages. Many users are especially happy graphical interface with support for the native language and the ability to control with the mouse. However, fans of the seventh Windows versions will have to upset. Its installation in computer systems with UEFI support, it looks not that unreasonable, and sometimes it becomes completely impossible. Otherwise, the use of UEFI looks very simple, not to mention some additional functions that can be used even without loading the operating system.
UEFI Secure Boot- this is standard protection on the BIOS, which limits the ability to run USB media as boot disk... This security protocol can be found on computers with Windows 8 and newer. Its essence is to prevent the user from booting from Windows Installer 7 and below (or an operating system from another family).
This function can be useful for the corporate segment, as it prevents unauthorized booting of the computer from unauthorized media that may contain various malware and spyware.
Ordinary PC users do not need this feature, on the contrary, in some cases it can even interfere, for example, if you want to install Linux together with Windows. Also, due to problems with the UEFI settings, an error message may appear while working in the operating system.
To see if you have enabled given protection, it is not necessary to go to the BIOS and look for information about this, it is enough to do a few simple steps without exiting Windows:
Depending on the motherboard manufacturer, the process for disabling this feature may look different. Consider options for the most popular motherboard and computer manufacturers.
Method 1: For ASUS
Method 2: For HP
Method 3: For Toshiba and Lenovo
Here, after entering the BIOS, you need to select the section "Security"... There should be a parameter Secure Boot, opposite which you want to set the value "Disable".
Method 4: For Acer
If everything was relatively simple with previous manufacturers, then the initially required parameter will not be available for making changes. To unlock it, you need to put a password on the BIOS. This can be done according to the following instructions:
Many users, who are not particularly versed in the settings of primary I / O systems, quite often come across the Legacy USB Support item among the huge number of various parameters. What is it in BIOS, why this option is needed, no one really understands, since its default value is usually set to Auto. However, sometimes you need to change this parameter. That is why it should be considered separately.
Legacy USB Support - what is it?
If we talk about the function itself based on its name, it is not difficult to guess its purpose. Simple enough to translate this term with of English language... The interpretation of this option assumes support for devices that connect to a computer or laptop through the appropriate interfaces and ports, just at the level of the primary system, as it was originally provided for all other hardware connected to motherboard.
But if we talk about the fact that this is Legacy USB Support, in this particular case we are talking exclusively about peripheral devices (mice, keyboards, etc.). Sometimes this parameter can also apply to removable storage devices. And although this is not directly stated, quite often the problems associated with the fact that some types of flash drives are not detected when they are installed as the first boot device are eliminated by just activating this option. However, as practice shows, these are isolated cases, and they are mainly associated with devices from little-known manufacturers or specific equipment that does not initially have support in the BIOS.
How do I enable Legacy USB Support?
Now a few words about what actions can be performed with such parameters. To get started, just look at its initial default value. This is usually the option to automatically select support (Auto).
But what is it? In Legacy USB Support, if you expand the list of all possible options set values, you can see both the activation (Enabled) and the deactivation (Disabled). What is it for? Only so that the user can choose for himself whether he needs such support. Of course, in the case of flash drives, if they are not detected even in the case of preliminary insertion into the port, after which the computer is turned on and then entered into the BIOS parameters, the activation of this parameter is mandatory. Roughly speaking, you need to first insert the flash drive into the USB port, and only then turn on the power for the download to begin.
Is it advisable to activate this option?
But, since the inclusion of the option is mostly related to the periphery (most often, as already mentioned, with mice and keyboards), many users have legitimate doubts about its activation. Is the system itself incapable of identifying such components? It goes without saying that if we are talking specifically about the operating system in which the operation of such devices is responsible installed drivers, there should be no questions. But few people pay attention to the moment that with disabled support, such devices become unavailable at the moment the computer or laptop is turned on (even before the main operating system is loaded).
In other words, an external USB keyboard cannot be used even to log into BIOS settings... This is why completely disable this parameter not recommended under any pretext. Generally speaking, it is better not to change the automatic value for choosing whether to enable or disable support at all! But if you work with outdated modifications of Windows like the network version of NT, this option must be enabled without fail.
When it is deactivated, it will often be possible to observe a loss peripherals operability, which will be stated in the properties of the equipment in the "Device Manager" (the device is disabled, it must be turned on, etc.). What is the saddest thing is that there is no way to activate disabled devices in the manager in such a situation.
Outcomes
What is Legacy USB Support, most likely, many have already figured out. As for the main conclusion, which can be drawn from all of the above, it should be noted that the default value of automatic activation or deactivation should not be changed if the specified support is necessary, otherwise you will not be able to enter the primary system later. You will have to additionally connect old PS / 2 keyboards and mice. But what if there are no such slots on the laptop, the main keyboard is out of order, and the USB ports also do not work with disabled support? Here's your answer!
BIOS is a well-known term among computer owners and has been used for many years. In the fall of 2017, Intel announced its plans to completely phase out BIOS on all of its platforms by 2020. Instead of BIOS, it will now use only UEFI, which may lead many to a logical question: what is UEFI better BIOS and what is the difference between them?
BIOS chip on a Gigabyte motherboard.
UEFI and BIOS belong to the category of so-called "low-level" software, which starts even before the computer starts to load the operating system. UEFI is more modern solution and it supports many convenient features that are useful on modern computers. It often happens that manufacturers call UEFI on their computers the traditional word “BIOS” so as not to confuse the user. Still, there is a big difference between UEFI and BIOS, and modern computers are mainly equipped with UEFI.
What is BIOS
BIOS is short for “ BasicInput-OutSystem" or " basic input-output system "... It lives on a special chip inside the motherboard (pictured above) and does not depend on whether it is installed in computer hard disk. When you turn on the computer, the first thing to do is to turn on the BIOS. This system is responsible for "waking up" the hardware components of your computer, checking their normal functioning, activating the bootloader and then starting the operating system.
As old as the BIOS world.
The user can configure a large number of different parameters within the BIOS. Component configuration, system time, boot order, and so on. You can enter the BIOS using a special key while turning on the PC. It can be different for different computers. For example, Esc, F2, F10, or Delete. The manufacturer decides which one to choose. After changing the settings, all parameters are written to the motherboard itself.
The BIOS is also responsible for a process called POST - “ Power-OnSelf-Test” or " power-on check "... POST verifies the suitability of the computer configuration and the health of the hardware components. If something goes wrong, a corresponding error is displayed on the screen, or the computer starts emitting a number of certain sounds (there is also the concept of POST codes and some motherboards even have a corresponding display installed to display them). The intensity of these sounds depends on the type of error, and to decipher them, you need to refer to the manufacturer's website or to the user manual.
After the POST completes, the BIOS looks for a Master Boot Record (MBR) or "Master Boot Record" that is stored on the computer's media. Then the bootloader (bootloader) is initialized and the operating system starts. The BIOS also often uses the term CMOS, which stands for “ ComplementaryMetal-OxideSemiconductor" or " auxiliary metal oxide semiconductor". This designation special memory, which is powered by a battery built into the motherboard. The memory keeps in itself various settings BIOS and often to reset BIOS parameters are advised to remove the battery from the motherboard. In modern computers, flash memory (EEPROM) has replaced CMOS.
Why BIOS is outdated
BIOS is a very old system that existed back in 1980 (and was developed even earlier), at the time start MS-DOS... Of course, over time, the BIOS has evolved and improved, but the concept and basic principles of operation have remained the same. The development of BIOS is virtually zero when compared with the development of computers and technology in general.
The traditional BIOS has many serious limitations. For example, he can start the system only from a partition with a volume of no more than 2.1 TB (maximum 4 partitions) or less. In modern realities, users buy very capacious drives, the volume of which often exceeds 4 or even 8 TB. BIOS will not be able to work with such media. This is due to the way the MBR works (the master boot record uses 32-bit elements). In addition, the BIOS operates in 16-bit mode (since it was developed back in the 70s) and has only 1 MB of addressable space for operation. The BIOS also has problems initializing a large number of components at once, which leads to a slow start of the computer.
The BIOS has been in need of replacement for a long period of time. Intel started development of EFI (Extensible Firmware Interface) back in 1998 and Apple switched to EFI in 2006 with the move to Intel architecture. In 2007 Intel, AMD, Microsoft and various manufacturers computers have approved the UEFI specification - " Unified Extensible Firmware Interface" or " unified extensible firmware interface"Windows got UEFI support in Windows Vista SP1 and Windows 7. Today, almost all computers use UEFI instead of BIOS.
Why UEFI is better than BIOS
UEFI is installed instead of BIOS on various PCs that you can find in electronics stores. It should be noted right away that the user cannot switch from BIOS to UEFI on existing hardware. To do this, you need to purchase new hardware that supports UEFI. The vast majority of UEFI computers include BIOS emulation (often called Legacy BIOS) so that the user can install and boot an older operating system that requires a BIOS to run. In other words, UEFI is backward compatible.
Much more modern and user-friendly UEFI interface.
The new standard has gotten rid of the nasty BIOS limitations. A computer with UEFI can boot from drives larger than 2.2TB. In theory, the maximum storage capacity for UEFI is 9.4 ZTB (9.4 trillion gigabytes). This is a lot. The whole point is that UEFI uses a GPT scheme with 64-bit elements ..
UEFI runs in 32 and 64 bit modes, and also has more memory to run. This in turn translates into faster CPU usage and usability. UEFI systems often have beautiful interfaces that support mouse input (pictured above). There are a number of other benefits as well. For example, UEFI supports Secure Boot. it special procedure, which checks the operating system being loaded and makes sure that during its boot, malicious or simply third-party software will not interfere. Also in UEFI there is support for various network functions, which is useful when solving technical problems with a computer. In the traditional BIOS, the user must have physical access to the computer, while in UEFI there is the possibility remote access for configuration.
All in all, UEFI is such a small operating system. It can be stored in the flash memory of the motherboard, or it can be loaded from the hard / network drive. Different computers with different UEFIs have no less different interfaces and capabilities. It all depends on the preferences of your computer manufacturer.
UEFI has been a big update for modern computers, but the vast majority of users are unlikely to notice any significant difference. And many are not interested in this question at all. Still, you need to understand that the arrival of UEFI instead of BIOS has become an extremely positive evolutionary change in the world of modern computers, even if all its charms and innovations remain hidden deep in the computer's motherboard. Now the industry is still in a transition from BIOS to UEFI, so all the delights of the new standard will be revealed in the near future. To speed up this process, Intel decided to ditch the BIOS entirely until 2020, which is a good thing.