Operating System.pptx

Ppt of Os

1. Operating System ISHA GOSWAMI Roll- 80 Univ. Roll- 10900120082 Operating System CSE 3rd Year, Sec-B Netaji Subhash Engineering College

2. BOOTING: In   computing ,  booting  is the process of starting a  computer  as initiated via  hardware  such as a button or by a  software  command. After it is switched on, a computer's  central processing unit  (CPU) has no software in its  main memory , so some process must load software into memory before it can be executed. This may be done by hardware or  firmware  in the CPU, or by a separate processor in the computer system. Restarting a computer also is called  rebooting , which can be "hard", e.g. after electrical power to the CPU is switched from off to on, or "soft", where the power is not cut. On some systems, a soft boot may optionally clear  RAM  to zero. Both hard and soft booting can be initiated by hardware such as a button press or by a software command. Booting is complete when the operative  runtime system , typically the  operating system  and some applications, [ nb 1]  is attained. The process of returning a computer from a state of  sleep  (suspension) does not involve booting; however, restoring it from a state of  hibernation  does. Minimally, some  embedded systems  do not require a noticeable boot sequence to begin functioning and when turned on may simply run operational programs that are stored in ROM. All computing systems are  state machines , and a reboot may be the only method to return to a designated zero-state from an unintended, locked state.

3. Concept of 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.

4. 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.

5. Steps of Booting: We can describe the boot process in six steps : The Startup: It is the first step that involves switching the power ON. It supplies electricity to the main components like BIOS and processor. BIOS : Power On Self Test: It is an initial test performed by the BIOS. Further, this test performs an initial check on the input/output devices, computer’s main memory, disk drives, etc. Moreover, if any error occurs, the system produces a beep sound. Loading of OS: In this step, the operating system is loaded into the main memory. The operating system starts working and executes all the initial files and instructions. System Configuration: In this step, the drivers are loaded into the main memory. Drivers are programs that help in the functioning of the peripheral devices. Loading System Utilities: System utilities are basic functioning programs, for example, volume control, antivirus, etc. In this step, system utilities are loaded into the memory. User Authentication: If any password has been set up in the computer system, the system checks for user authentication. Once the user enters the login Id and password correctly the system finally starts.

6. Thank You!!