Booting process

 

How booting process works 

Concept of Booting:

Booting :

        Booting is basically the process of starting the computer. When the CPU is first switched on it has nothing inside the Memory. In order to start the Computer, load the Operating System into the Main Memory and then Computer is ready to take commands from the User. Learn the types of booting.

What happens in the Process of Booting?

        Booting happens when you start the computer. This happens when we turned ON the power or the computer restarts. The system BIOS (Basic Input/Output System) makes the peripheral devices active. Further, it requires that the boot device loads the operating system into the main memory.

Boot Devices :

        Booting can be done either through hardware (pressing the start button) or by giving software commands. Therefore, a boot device is a device that loads the operating system. Moreover, it contains the instructions and files which start the computer. Examples are the hard drive, floppy disk drive, CD drive, etc. Among them, the hard drive is the most used one.

Types of Booting :

There are two types of booting:

Cold Booting :

        A cold boot is also called a hard boot. It is the process when we first start the computer. In other words, when the computer is started from its initial state by pressing the power button it is called cold boot. The instructions are read from the ROM and the operating system is loaded in the main memory.

Warm Booting :

        Warm Boot is also called soft boot. It refers to when we restart the computer. Here, the computer does not start from the initial state. When the system gets stuck sometimes it is required to restart it while it is ON. Therefore, in this condition the warm boot takes place. Restart button or CTRL+ALT+DELETE keys are used for warm boot.

Booting Process :

We can describe the boot process in six steps:



Step 1: BIOS is loaded :When we turn on the power, the first step in the booting process is to load the BIOS. The power supply provides electricity to essential components, including the processor and BIOS.
Step 2: BIOS: Power on Self-Test :After loading the BIOS, it performs a Power on Self-Test (POST). This test checks the computer's main memory, disk drives, input/output devices, and other hardware components. If errors are detected during the test, the system emits beep sounds or displays on-screen notifications to alert the user.
Step 3: Loading of OS :Once the POST is successfully completed, the BIOS reads the bootable sequence stored in the CMOS (Common Metal Oxide Semiconductor). Based on the bootable sequence, the BIOS searches for the Master Boot Record (MBR) on bootable devices such as floppy disks, CD-ROMs, and hard disks.
If the MBR is not found on bootable devices, the system displays a message saying "No Boot Device Found" and crashes. However, if the MBR is found, the BIOS launches a boot loader, a specialized application software that loads the operating system.
Step 4: System Configuration :After the operating system is loaded, device drivers are loaded into memory to ensure the proper operation of the computer's hardware components. These device drivers act as intermediaries between the operating system and the hardware, allowing them to communicate effectively.
Step 5: Loading System Utilities :In this step, the booting in operating system process involves loading system utilities into memory. System utilities, such as antivirus software and volume control, are essential tools that enhance the functionality and security of the operating system.
Step 6: User Authentication :If any user authentication is configured, the system prompts users to input their credentials. Once the system receives valid credentials, it typically launches the graphical user interface (GUI) shell or the command-line interface (CLI) shell, providing the user access to the system's resources and applications.

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