Linux Boot Process

Power-On Self Test (POST) that is performed by the compter's Basic Input/Output System (BIOS)
-- FOR - -- an internal check of the system's internal components checking normally involves the system RAM, CPUs, video card, hard drives,
-Will chk from BIOS for media to boot.
-the BIOS reads the MBR on the hard disk and loads the program that is found there into memory.
-The Master Boot Record (MBR) is the first 512 bytes of the boot drive that is read into memory by the BIOS.The first 446 bytes of that 512 will normally contain a low-level boot code that points to a boot loader somewhere else on the disk
-The GRUB bootloader is a program written in /boot partition of a hard drive that loads the operating system.
-GRUB transfers control to the kernel and the kernel is booting,
-What is actually going on at this time is that the kernel is probing your hardware and configuring itself for your hardware. The kernel is also loading modules in the initrd image that it needs to operate your hardware
-Once the kernel is done with its initialization, it starts the system's first process, which is /sbin/init.
-Init is the first process running on your system with a Process ID (PID) of 1.It reads the /etc/inittab file, executes /etc/rc.d/rc.sysinit, then boots into the runlevel as defined in /etc/inittab.
-Init will also normally start several instances of /sbin/getty or /sbin/mingetty, which are your virtual terminals.