BIOS is a firmware on a computer system that functions to initialize hardware when the computer is turned on (boot) and provides services (runtime service) to run hardware to the operating system or other software when the computer is on. BIOS (spelled: By-oss) stands for “Basic Input Output System”.
BIOS was first introduced by “Gary Kidal” in 1975 in the C/PM (Control/Program Monitor) operating system, he also explained the BIOS functions from initialization to booting technically in a documentation.
The computer BIOS firmware is stored in the BIOS chip located on the motherboard, in the form of a Flash ROM, EEPROM, or NAND Flash.
Firmware is a kind of small piece of software that is stored in a specific piece of hardware (usually some kind of ROM) and written in a machine programming language to provide speed when interacting with the hardware.
B. BIOS Function on Computer
The following are 4 BIOS functions on a computer, including operating functions, extension functions, operating system service functions, and configuration functions.
B1. Operation Function
The operating function is the use of the BIOS to initialize the computer system when it is turned on to enable bootable devices, such as the hard drive that contains the operating system. Here are some of the things the BIOS does regarding operating functions.
Startup System Management (Startup System)
Early series Intel processors had a physical address (000FFFF0h) in the computer’s memory to run the BIOS. The next development, computer processors can generate artificial addresses (logical addresses) to run the BIOS from the ROM that stores it.
- When the BIOS is activated in memory by the processor after pressing the power button (“cold boot”), the BIOS performs a power-off self test (POST). This process aims to check the devices on the computer system including: verification of the BIOS code, RAM, CPU, VGA, identification of input/output hardware, to detecting other existing devices, such as hard drives. This information is usually displayed on a computer screen.
Running the Boot Process (Boot Process)
After the BIOS has finished checking the POST firmware to other hardware, it is continued by detecting the drive and disk (storage) devices that allow storing boot files such as hard drives, room-drives, to flash disks. BIOS performs checks on each drive/disk and sorts each drive/disk.
Checks are carried out on the boot-sector of each drive/disk, and when detected to save the boot-sector, a device is called a bootable device/disk. The BIOS then activates the bootable device/disk, for example the operating system that has been installed on the hard drive or the operating system DVD inserted in the DVD-ROM. This is adjusted to the configuration sequence and availability of the bootable device/disk.
In addition, the BIOS can also enable non-storage devices as bootable, such as network adapters. For example, a GNU/Linux installation can use a network adapter as a bootable installer.
Setting Boot Priority (Boot Priority)
The BIOS can set the bootable device/disk priority and can give the user options when it detects more than one bootable device/disk available to run during the boot process. More modern BIOSes provide a custom boot configuration menu that is accessible to the user.
Boot Error Management (Boot Failure)
The BIOS gives various error messages when the computer does not boot properly. At first IBM computers display the message “No ROM Basic”, then more modern computers usually display the message “No Bootable Disk Found”
B2. Extension Function
The extension function is the use of the BIOS for the management of connected hardware such as several installed hard drives, some existing VGA, mouse, keyboard, and others. The management of these enhancements is connected via a ROM extension chip which provides different functions according to the device. The extension function is directly connected to the ports and other firmware chips on the motherboard.
B3. Operating System Service Functions
The following are some of the operating system service functions provided by the BIOS.
Provide Hardware Input Output Access
The main function of the operating system service BIOS is to provide services to the operating system or other software in the form of a small library of input and output functions to access hardware (hardware), such as: running the keyboard, mouse, monitor, writing disk/drive, and other hardware functions. connected.
Granting Boot Access
Initially the boot process before entering the operating system, everything is done by the BIOS. On modern computers after performing a power-off self test, the BIOS can immediately provide boot access to the operating system, for example Windows 10 which uses fast boot technology. This causes the boot process to run faster, because the BIOS no longer needs to read the bootable drive when the power button is pressed and system RAM access is also directly handed over to the operating system.
Granting Access to Microcode Updates
On modern computers, the BIOS can give the operating system access to updating the firmware of a piece of hardware. The firmware version of a device is called microcode and is stored as a machine code in the device’s special memory. This memory can be EEPROM, Flash Chip, PLCC, and others.
Providing System Identification Access
BIOS can provide access to the operating system to identify system devices, newly installed devices, and perform device monitoring. For example, to read the processor name, heat the processor, detect new hardware, read memory usage, and others.
Giving Clocking Access
BIOS can give access to the operating system to set the clock speed of a hardware device such as CPU and VGA. It is usually used by gamers to overclock the system to speed up the running of a game. Clocking is not only limited to setting the speed, setting the use of electricity is also provided by the BIOS.
4. Configuration Function
Providing a Setup Utility Interface
Initially on IBM computers, the BIOS did not provide an interface (User Interface) to configure the BIOS which was called the “Setup Utility”. Along with the development of technology, this feature is embedded in the BIOS to simplify the configuration of the computer system. To access Setup Utility, it is common to use the F1, F2, F10, F12, or DEL keys when the BIOS displays a POST message. The following are some of the features provided in the Setup Utility interface.
- Manage hardware configuration, including additional configuration, features, and speed
- Setting the date and time, the BIOS uses the CMOS battery to store configuration data and calculate the time.
- Enable or disable a hardware
- Setting the boot process including the order
- Provides security features such as BIOS password and disk password
Provides Monitoring Features
Modern BIOS provides additional features for monitoring the system, such as processor temperature, case temperature, voltage, processor fan speed control, and others. This feature is usually named “PC Health Status” or “Hardware Monitoring”.
BIOS Firmware Reprogramming
Reprogramming firmware is a feature that serves to reinstall the BIOS microcode data or update the BIOS chip. Users can update via a flash disk containing BIOS microcode data through the “Setup Utility” interface. BIOS data is usually referred to as a “BIOS Image” which can be obtained from the motherboard manufacturer’s site or the BIOS manufacturer’s website. A BIOS update error can cause the computer to completely shut down and it is necessary to flash the BIOS chip with a flashing tool. More modern motherboards may provide a BIOS image backup feature to mitigate the risk of BIOS firmware update failure.
C. How to Setup BIOS Configuration
The following is an example of a computer’s BIOS configuration settings.
- Restart Computer
- Quick read the instructions from the BIOS POST message regarding the key to access the “press key to enter BIOS Setup Utility” , “press key to enter CMOS Setup Utility” , or similar message
- Press the key continuously ( usually F1, F2, F10, F12, or DEL ) until “BIOS Setup Utility” opens
- Refer to the keyboard key instructions (bottom) for navigating the “BIOS Setup Utility” interface and menu information (right)
- The “Main” menu contains computer information regarding BIOS version, date configuration, installed drives, system information
- The “Advanced” menu contains available advanced configurations such as VGA Adapter, Sound Adapter, LAN, PATA, SATA, PS/2 Mouse, etc.
- The “Security” menu contains configuration of security passwords, disk passwords, secure boot menus, and more.
- The “Boot” menu contains the configuration of the bootable device priority order
- The “Exit” menu contains commands related to exiting the BIOS and saving configuration settings (Save Changes and Exit) , cancel settings (Exit Without Saving), or use standard settings (Load Defaults Setting and Exit)
Please to also read about how to enter BIOS menu on Windows computer.
D. Computer BIOS Type
There are 2 types of computer BIOS, namely UEFI and Legacy BIOS.
- UEFI (Unified Extensible Firmware Interface)UEFI is the traditional BIOS replacement firmware used on modern computers, with an interactive interface that is smoother, faster, and capable of handling drives over 2.1 TB. Most computers that support UEFI can enable legacy BIOS mode. In 2020, the manufacturing company Intel stopped using Legacy BIOS in its new motherboard products and used UEFI in its entirety.
- Legacy BIOSLegacy BIOS is a type of BIOS used by older computers that only has a text interface and is only capable of handling a maximum of 2.1 TB drives. Some modern computers that support UEFI BIOS usually enable Legacy BIOS as the default interface.
E. Popular Computer BIOS Manufacturing
Here are some of the popular computer BIOS manufactures that many computer manufacturers use.
- American Megatrends Inc. (AMI BIOS)
- Phoenix Technologies BIOS
- Ali BIOS
- Winbond BIOS
So the article “BIOS | Understanding Computer BIOS and its Functions”. Look forward to other interesting articles and please be willing to share and like the Advernesia page. Thank you.