Linux Boot Sequence

Note:-   The BIOS tests the system, looks for and checks peripheral devices, and then looks for a drive to use to boot the system. The BIOS looks for a Master Book Record (MBR) starting at the first sector on the first hard drive, loads its contents into memory, and then passes control to it. First 512 bytes.The MBR then find and loads the GRUB Boot Loader GRUB finds the necessary boot file, which initializes the kernel and the initial ram disk.
Once the kernel has successfully loaded, it executes /sbin/init. Init parses its connfiguraiton file (/etc/inittab) and finished the boot process according to its configuration. 


Bios Intialization

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Boot Loader (GRUB or LILO)

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Kernel Intialization

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Init Starts and enter desired runlevel by executing(/etc/inittab).

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/etc/rc.d/rc.sysinit  [Entering Runlevel [0-6] ]

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/etc/rc.d/rc   &   /etc/rc.d/rc[0-6].d/

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/etc/rc.d/rc.local

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Virtual Consoles

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X display manager