# Preface
Some embedded Linux also supports network ports, such as RGMII. The embedded system resources support hardware platforms (board or system-on-chip) with Ethernet and other basic interfaces. There are sufficient NOR or NAND Flash memories to accommodate OS, lib library, fileSystem file system, APP application, Bootloader guide program, etc. Embedded Linux is open source, modifiable, and written in C. Drivers can be added according to the added hardware chip devices as needed for use by upper application layer applications.
Because embedded Linux is designed for specific applications, you must have some specific development tools when starting a system design that requires an open source OS. A good starting point is to use the right libraries, a powerful cross-compiler, and an efficient bootloader to pair with the Linux kernel. An example is a cross-compiler, which is a compiler that executes code written to run on a machine other than the one on which the compiler is built. For example, a cross-compiler running on a desktop or PC laptop can generate code written for embedded systems such as Android smartphones.
The C library provides the interface between the kernel and applications and therefore must be part of the cross-compilation process. Any program in an embedded Linux system, whether written in python, java or other languages, must call C at runtime. Library to access hardware resources through the Linux kernel. like