How Computer Boots up?
HAVE YOU EVER THINK WHATS HAPPENED BEHIND THE LOGO OF WINDOWS 7/10 OR LINUX? WHEN YOU BOOT UP YOUR COMPUTER, From the pressing of the power button there are more than hundred components that are initialized and million lines of code is executed during the process of booting. But what is booting?
What is Booting?
Booting is a process or set of operations that loads and hence starts the operating system, starting from the point when user switches on the power button.
– Turn on the Power button.
– CPU pins are reset and registers are set to specific value.
– CPU jump to address of BIOS (0xFFFF0).
– BIOS run POST (Power-On Self Test) and other necessary checks.
– BIOS jumps to MBR(Master Boot Record).
– Primary Bootloader runs from MBR and jumps to Secondary Bootloader.
– Secondary Bootloaders loads Operating System.
These are the tasks that are carried during booting process. Now let us discuss them in detail.
1.Electricity goes from Socket to the POWER SUPPLY
Power Supply converts the alternate currant into a direct current and then delivers proper voltage and electricity to other computer components
2.Signal goes to the CPU as we cll it PROCESSOR
CPU ( Central Processing Unit ) looks into BIOS (Basic Input-Output System)contained in the ROM (Read Only Memory)for the first instructions.
The first instruction is to run a POST. Basically,it checks if everything in its place and working fine.
– Checks the real-time clock (RTC) and the computer system bus.
– Check the CMOS, Where the system time and hardware into is kept.
– Begins comparing the system setting with hardware.
– Tests the computer memory (RAM) and then the POST will test each floppy. Optical, and hard drive.
4. Operating System
When the POST is successfully completed, the whole control is handed over to the Operating System (OS). According to statistic, post probably,your OS is Windows .