In recent years, with the development of embedded computers as well as the appearance of various kinds of heterogeneous embedded hardware, it is a trend to improve the portability of operating systems and the code reusability of application programs. In this paper, we introduce a platform abstraction layer with strong universality, which is designed for Linux and ReWorks operating systems and hardware platforms. Specially, the platform abstraction layer redesigns the application programming interface to provide a unified interface to users to develop various embedded applications. It is proved that the platform abstraction layer can improve the portability of operating systems and the code reusability of application programs. At the same time, it has reliability in terms of real-time performance.