What Is Booting Process In Operating System? Understand The Concept Of Booting
Table of content:
- What is Booting?
- Sequencing Booting
- Steps of Booting Process in OS
- Steps Of Booting Process in DOS OS
- What Is Secure Boot?
- What is Dual Booting?
- Boot Configuration Data
- Frequently Asked Questions
When our computer is turned on, it can start by hardware like pressing a button, or by software command. CPU does not have any software stored in its main memory. There is a process that must load the software into the main memory before it is able to be executed.
When the computer is switched on, a particular program must be loaded into the memory of the computer that is called the Operating System.
In the procedure of booting it will scan all the Hardware and Software that are connected or installed to the system, as well as all the files that are needed to run a system. and also load them into memory.
ROM also reads the information contained in the files. When the system is booting, all the Instructions are read to begin the system. Discussing all the things about booting but the important question is What is booting?
What is Booting?
Booting is the process of beginning a computer. It is initiated either by hardware like the press of a button, or the software command. When it is turned on, the CPU has no software installed in its primary memory, and therefore certain processes require loading software into memory prior to execution. This can be accomplished by hardware devices, software, or firmware within the CPU or by a separate processor inside your computer.
Restarting computers is also known as rebooting. It may happen “hard”, e.g. the power supply on the CPU has been switched off to on as well as “soft”, where the power is not interrupted. In some systems, a soft reboot can also clear the RAM down to zero. Soft and hard booting can be initiated via hardware, like a button press or a command from software. Booting is complete once the operating runtime system usually the operating system as well as some applications, are reached.
Types of Booting Process
There are two types of the Booting process, this category of booting process that OS holds at the time of booting:
1. Hard Booting/Cold Booting
2. Soft Booing/Warm Booting
1) Hard (Cold) Booting
Restarting a computer can be also known as rebooting. it can happen “hard” or “cold”, e.g. when the power supply on the CPU has been switched off and on. In this case, beginning the boot process, the computer begins from an unresponsive state.
In Cold booting when a power failure, when we hit the Power Button, the system begins in the initial configuration. It reads the entire information to be stored within the Read-Only Memory (ROM) and instantly that Operating System will be loaded into the main memory of the system.
2) Soft (Warm) Booting
When you boot in “soft” or warm booting there is no power shut off. On some systems soft booting, it is possible to be able to clear RAM down to zero.
Soft Boot can also be called warm booting. This refers to the time when the computer is restarted. The computer is not able to start from its initial state. Sometimes the computer will not start if it gets stuck. In this situation, the warm boot is activated. When we require rebooting we must install hardware and software.
Hardware configuration changes the system. The warm/Hot Booting process is when computer systems come to no response or hang state, and then the system is allowed to restart during on condition. The hot booting process can be accessed by pressing CTRL+ALT+DELETE or the Restart button.
When a computer is turned on, it starts its operating system by booting. The computer’s initial set of operations when it turns on is called a boot sequence. Each computer has a boot sequence.
1. Boot Loader: The central processing unit cannot execute code stored in the system’s memory. Modern operating systems, application program code, and data are being used by non-volatile memory. The code and data in the nonvolatile memory must be used when a computer is turned on for the first time. The operating system is not loaded and the hardware of the computer cannot perform complex system actions, at the time of booting which is called boot time.
This is the program that initiates the chain reaction that results in the entire operating system being loaded. The boot loader is responsible for loading other software and it allows the operating system to begin.
2. Boot Devices: This is the device that loads the operating system. Modern PC BIOS (Basic Input/Output System), supports booting in various devices. These devices include a local hard drive, optical drive, and floppy disk drive. The BIOS allows the user to set a secure boot.
- CD Drive
- Hard Disk Drive
The BIOS will attempt to boot first from the DVD drive. If that fails, it will then try to boot using the hard drive. If that fails it will then try to boot via the network.
3. The Boot Sequence: All personal computers follow a common boot sequence. The CPU first runs an instruction stored in memory that is used for the BIOS. This instruction includes a jump instruction that transfers to the BIOS startup program. The program performs a power-on self-test (POST), to ensure that the devices it will depend on are working properly. Next, the BIOS runs the boot sequence to find a bootable device. After BIOS finds a bootable device it loads the boot section and transfers execution to that boot sector. If the boot device is a drive, it will be a master boot record (MBR).
The MBR code checks for active partitions in the partition table. The MBR boot code checks for an active partition, it loads the boot object. Although the boot sector can be specific to an operating system, it is primarily responsible for loading and running the operating system kernel. This allows for a continued start-up.
If there is no active partition or the boot sector of an invalid active partition, then this is what you do. The MBR can load a secondary bootloader that will load the boot sector of the selected partition. This usually loads the operating system kernel.
Steps of Booting Process in Operating System
If our computer is turned on, it is initiated by hardware like pressing a button, or by software commands, the computer’s central processing unit (CPU) does not have any software in its main memory There is a process that must load the software into the main memory before it is able to be executed. The following are the six steps for describing the boot procedure in the operating system. For instance:
Step 1: When the computer system has been switched off, BIOS (Basic Input /Output System) runs a set of functions or tests for programs stored in ROM, referred to as the POST (Power-on Self-Test) that tests to determine whether the peripherals on your system have been in good condition or not.
Step 2: Once the BIOS is completed with tests for functionality or pre-boot it reads the bootable sequences from the CMOS (Common Metal Oxide Semiconductor) and searches for the master boot record on the physical first sector on the bootable disk according to the boot device sequence defined in the CMOS. For instance when it is the sequence of the boot device:
- Floppy Disk Drive or Floppy Drive
- Hard Disk
Step 3: Following this, your master boot record will look first on the Floppy disk drive. If it is not found, the drive on the hard disk will look to find the master boot file. If it is found that the master boot data does not present on the disk then that’s when the CDROM drive will be searching. If the system can’t access the master boot file using any of the above sources, then ROM will display “ No Boot device was found” and halted the system. After finding the master boot record of a specific bootable disk drives an operating system loader often known as Bootstrap loader loads from the section that contains the boot sector of that bootable drive into memory. The bootstrap loader is a specific program that is located inside the partition for booting of the drive that is bootable.
Step 4: Bootstrap loader initially loads it with the IO.SYS file. Then, MSDOS.SYS file is loaded. This is the main file of the DOS operating system.
Step 5: After that, MSDOS.SYS file searches to locate Command Interpreter in CONFIG.SYS file and, if it locates it, it is loaded into memory. If there is no Command Interpreter is listed within the CONFIG.SYS file, then the COMMAND.COM file is loaded as the default Command Interpreter of the DOS operating system.
Step 6: the last document that needs to be downloaded and run is an AUTOEXEC.BAT file, which contains a sequence of DOS commands. The prompt will be displayed. The drive’s letter for bootable drives is shown on the computer system which means that the operating system is successfully running on the system via the drive.
Steps Of Booting Process in DOS Operating System
For DOS it starts the process of booting at the time we boot our computer and continues until the DOS prompt appears. The booting process in DOS is mostly focused on loading three of the main system files from DOS in memory. These include IO.SYS, MSDOS.SYS and COMMAND.COM.
The booting process for DOS these steps are followed every time we boot a PC -
Step 1: When the computer system is powered up, BIOS (Basic Input/Output System) runs a set of functions or tests on programs in ROM. This is known as the “Power-on Self Test” (POST) tests to verify whether the peripherals on the system are functioning properly or not.
Step 2: After the BIOS This is accomplished by the pre-boot process or a functional test is done by reading the bootable sequence from CMOS (Common Metal Oxide Semiconductor) and searches for master boot record within the initial physical segment of the bootable disk, according to the boot device sequence as specified in CMOS. For instance, if the initial boot sequence of the device is the following:
- Hard Disk Drive
- Floppy Disk Drive
Step 3: The master boot record is searched first on a Floppy disk drive which is a bootable disk drive. If it is not found, the hard disk drive is searched for the master boot record. If it is found that the master boot records aren’t found on the hard disk and the CDROM drive is not found, then the drives will also be searched. If the system isn’t capable of reading the master boot records from one of these resources, ROM displays the message “ No Boot device was found” and the system is stopped. When it finds the master boot record on the removable disk, the operating system loader also referred to as Bootstrap loader is loaded from its boot sector on that bootable drive into memory. The bootstrap loader is a special program that is located in this boot sector on bootable drives.
Step 4: The bootstrap loader loads first its IO.SYS file. Then, MSDOS.SYS file is loaded, which is the core file of the DOS operating system.
Step 5: Then, MSDOS.SYS file seeks out Command Interpreter within the CONFIG.SYS file and when it does the file, it is loaded into memory. If there is no Command Interpreter was specified is specified in CONFIG.SYS file, CONFIG.SYS file, the COMMAND.COM file is loaded as the default Command Interpreter of the DOS operating system.
Step 6: The last file that needs to be downloaded and run is an AUTOEXEC.BAT file that is a set of DOS commands. Following this, the prompt appears, and we can view the letters for the drive that are bootable that is displayed on the computer to indicate that the operating system is running successfully running on the system via the drive.
What Is Secure Boot?
Secure Boot is a protocol that secures the boot process by preventing operating systems and drivers from starting up if they aren’t authentically signed with a genuine digital sign-off. In simple terms, it guarantees it’s the OS you’re running is genuine and not a fake one. as genuine.
Steps to Disable Secure Boot
The disabling of Secure Boot is only done by using UEFI (sometimes known as its precursor, BIOS (sometimes called BIOS). Follow the steps to enable it and disable Secure Boot:
- Restart your PC.
- As soon as it begins to boot up, you’ll be required to click the UEFI icon to input the code. It varies from system to system and it may require the help of a guide, but usually, it’s deleted, escaping F1 2 F2, F2, and F12.
- Search to Find an Search for a section, and then navigate there with your mouse or keyboard. Navigating to the different UEFI differs for every manufacturer, so be sure to read the manual for assistance if you need it.
- Look to find The Secure Boot alternative. Toggle it to disabled.
- Utilize the keyboard the F10 key to ensure that your preferences are stored, then restart your computer.
- It may take some time to start in. Secure Boot will be disabled.
For enabling Secure Boot to be enabled, you must first uninstall any hardware or software that could affect it. Follow the steps above in the same manner and change Secure Boot and off to Enabled instead.
What is Dual Booting?
If there are two different operating systems installed on a computer system, it is known as dual booting. On your systems, multiple operating systems may be installed. However, to determine which operating system will boot, you need a boot loader that can handle multiple file systems and operating systems could be in that boot disk.
After being loaded, it will start one or more operating systems that are available in the disc. The disk may have several partitions, each with an operating system. When a computer is turned on it, a boot manager application shows a menu that allows users to choose which operating system they wish to choose from.
Boot Configuration Data
Windows Boot options are saved inside the Boot Configuration Data (BCD) database on computers with EFI or BIOS.
BCD offers a standard software-independent boot option interface to all PCs operating Windows 10, Windows 8, Windows Server 2012, Windows 7, and Windows Server 2008. It’s more secure than the previous configurations for boot options storage since it allows secure lockdown for the BCD store, and allows administrators to give rights to manage the boot options. BCD is accessible at all times throughout the setup process. You can also use BCD when you are in power state changes and use it to specify the boot procedure to resume after hibernation.
It is possible to manage BCD remotely, and also manage BCD when your system is booted using a different medium than the one that the BCD store is stored. This is crucial to debugging and troubleshooting issues particularly when BCD is a BCD store that has to be restored during the process of operating Startup Repair from a DVD or storage media that is USB-based or even remotely.
It is the BCD store, which has its familiar object-and-element structure that makes use of GUIDs and names like “Default” to accurately identify the boot-related software.
Frequently Asked Questions (FAQs):
The basic boot interview questions company generally ask are:
Q1. What is booting?
Ans. Booting is the process of beginning a computer. It is initiated either by hardware like the press of a button, or the software command. When it is turned on, the CPU has no software installed in its primary memory, and therefore certain processes require loading software into memory prior to execution.
Q2. What is the boot device?
Ans. Booting devices are devices that have the operating system loaded inside them during the boot process. Some of the booting devices are
- Hard Disk Drive
- Disk Drive
- Floppy drive
Q3. What are the types of booting?
Ans. There are two types of booting
- Cold Boot/Hard Boot
- Warm Boot/Soft Boot
Q4. Why do we need booting?
Ans. In computing, it is the act of the computer’s start-up process. When the computer is turned on the computer’s central processing unit (CPU) does not have any software installed in its memory or Random access memory. Therefore, the process needs to load applications into its memory so that they are able to run.
We do this to ensure it is that operating systems and the first files and instructions are loaded onto the memory of the main. In the end, the computer begins.
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