1, bootloader:BootLoader runs before the operating system kernel runs. You can initialize hardware devices and establish memory space mapping, so that the software and hardware environment of the system can reach a suitable state and prepare the correct environment for eventually calling the operating system kernel.

2. The basic Linux system provides a basic framework for the development of complex application software systems, with corresponding and convenient development and maintenance management tools.

3. File system is used to manage the storage space of embedded system. It should be considered as a part of the operating system, but because there are a lot of file system support parts in Linux source code, and the storage space of embedded system is limited, only one can be reserved, so this part needs more complicated processing.

4. Graphical user interface library, whose function is to provide a graphical environment for applications. Although it can also be regarded as a part of the operating system, due to the particularity of embedded systems, it often needs customization.

5. Device driver, because each embedded device may have its own unique device, it is necessary to develop a driver for it.

6. Application program, which specifically realizes the software required by users. Application programmer refers to the software developed through the development interface provided by the operating system to realize the functional utilization of the computer.