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PC's have a different boot sequence, first a ROM BIOS starts that give minimal configuration to peripherals, usually just configuring the screen and keyboard. It then looks in its tables (CMOS RAM) for a boot device.
From the specified boot device it loads to RAM the first stage (from MBR)
control is transferred to first stage.
First stage bootloader loads the second stage that usually displays the boot menu. The user selects the OS to boot or a default OS is booted after a speficied time. In this stage the user have the option to add boot parameters to kernel. In several cases, the bootloader does not know how to load the OS and transfers the control to another bootloader, this is called chain loading, this is usually done when LILO or GRUB needs to load windows.
Prepare parameters for OS loading
Allow manual intervention
|Prepared by Ori Idan Helicon technologies|