# Terminology in Embedded OS ### 1. U-Boot Linux needs a bootloader process to boot after power on. The bootloader would initialize the processor. After that, it would load the kernel to DDR and ready to run it. ### 2. kernel Kernel is the lowest layer in whole OS. It takes responsibility for hardware drivers, and provide the core functionality required by various systems. ### 3. root file system The root file system is first of all a file system. This file system not only has the function of storing data files like an ordinary file system, but relative to ordinary file systems, it is the first file system mounted when the kernel starts. The image file of the kernel code is stored in the root file system. The system boot program will load some initialization scripts (such as rcS, inittab) and services into the memory for running after the root file system is mounted.