Hello, Thanks for visiting RvKmR.blogspot.in You may be curious about what happens in background when you press an power button of an Linux PC/server. Well in this post I am going to explain about how Linux systems boots. I gone thorough lot of tutorials and came with below boot steps. Before going to process you must to be aware of ROM, RAM, CPU etc. OK, let's start !!! As soon as power button pressed system performs system integrity check, we call it as POST and load and execute boot loader to RAM. The module for performing POST and loading boot loader in RAM is available in ROM and which wont be lost when you power off the systems so that we call it as Read only memory. Then the cpu/processor comes in picture. processor having registers, some of them are AX, BX, CX, ISP etc. each of them having there own purpose. For now we are interested in ISP only, which is an instruction pointer in RAM. It means it holds address of instruction to run next. Loaded m