Booting (or Bootstrapping) is the process, or chain of stages of loading the basic software, usually the Operating System into the memory of a device during power-on or general reset.

Booting process involves a chain of stages, in which at each stage a smaller, simpler application loads and then executes the larger, more complicated application of the next stage. Typically this process starts with execution of hardware-based procedures and may then hand-off to firmware and software which is loaded into main memory. Booting often involves processes such as performing self-tests, loading configuration settings, loading a BIOS, resident monitors, a hypervisor, an Operating System, or utility Applications.

Booting Process#

Booting varies depending on the Device however, most Personal Computer type Devices follow this general outline:


The BIOS is a resident application such as BIOS, UEFI, U-Boot or Coreboot is executed from Firmware on power on or reset.

The POST process is part of the BIOS

Find a bootable Device#

The BIOS after the POST must then locate the bootable Devices. Typically this is performed by reading the Master Boot Record of the Storage devices that it has identified.

Load the Operating System#

Transfer Control Operating System#

Once the previous steps are complete and the Operating System is safely loaded into RAM, the Booting process relinquishes control to the Operating System and the User Interface

More Information#

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