What is booting ? Steps by step process of booting Explained

What is booting ? Steps by step process of booting

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Booting UP: -

Loading operating system files into main memory is called booting up or bootstrapping (which means getting ready) of the computer and then loading of operating system files in main memory.

Types of booting: -

1.    Cold booting: -It is the process that takes place when we first turn on computer. In cold booting all the below mentioned steps i.e., right from step 1 – POST onwards take place.

2.    Warm booting: - it is the booting process that takes place when we reset the computer by pressing Reset button. In this process, the first step of POST or RAM test or other diagnostic tests etc. is skipped; simply the OS files are reloaded. Warm booting can take only if computer was already running.

Steps of BOOTING: -

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1.    As soon as the machine is powered ON, POST (Power On Self-Test) is performed which are mainly diagnostic tests that check for integrity of all components (CPU, RAM, IO devices etc.) of a computer system. If any component is found faulty, am error message is displayed.

2.    A chip called ROM-BIOS (Read Only Memory – Basic Input Output Services) is read and executed. Then a check is performed for OS files’ presence on the disk. If nowhere OS files are located, following error message is displayed on the screen

                                   Non – system disk or disk error

3.    If OS files are found in drive, it’s very first sector (called MBR – Master boot Recorder or boot sector) is read which first looks for active partition.

4.    This secondary boot record now loads and runs the bootloader program. Every OS has a specific bootloader program that loads its specific OS files into main memory. Some popular bootloaders are:

·       NTLDR: - Bootloader for old WINDOWS Oss like Windows NT, Windows 2000, Windows XP, and Windows server 2003.

·       BOOTMGR: - Bootloader for newer WINDOWS Oss like Windows Vista, Windows 7, Windows 8, Windows 8.1, and Windows 10, as well as Windows server 2012.

·       GRUB & GRUB2: - Bootloader for an old and new Linux versions.

·       BOOTX: - Bootloader for MAC OS.

Advantages of cold reboot: -

The advantage of Cold reboot is that it releases anything that is stuck in memory. If you are getting error messages or other issues, it might be because something is stuck in memory. When you do a cold reboot, it clears the memory. A warm reboot doesn’t release items stuck in memory, only a cold reboot does. Thus, there might be some data loss or damage in a warm reboot.

- JAI HIND