I'm studying a little for an interview next week, and I've compiled this list as a way of summarizing the Linux Boot process. I've consulted various resources online, although, I would like to hear another human's opinion. I'm trying to keep this short, yet as descriptive as possible on all of the main functions. Any input will be greatly appreciated.
1. BIOS does Power On Self Test
2. BIOS retrieves information from CMOS like the time, date, and system information
3. BIOS determines primary boot device (PXE, HDD, CD, USB)
4. BIOS searches for valid MBR on boot device, once found BIOS loads MBR to RAM
5. MBR points to valid primary partition marked “bootable"
6. MBR points to the boot loader, either GRUB or LILO
7. Boot loader lists available boot options (user choice or starts default kernel)
8. Boot loader decompresses kernel into RAM. Then starts essential hardware and memory paging
9. start_kernel performs system setup (interrupts, memory management, device initialization, drivers, etc.)
10. start_kernel then begins the init process in user space
11. Init determines the default run level from /etc/inittab
12. Init runs all boot scripts in /etc/rc* directories
13. Init starts TTY sessions and user is presented with a login prompt
Last edited by rogue (2012-04-25 06:03:11)