Embedded system is a dedicated computer system as part of a device or device. Generally, an embedded system is an embedded processor control board whose control program is stored in ROM. In fact, all devices with digital interfaces, such as watches, microwave ovens, video recorders, automobiles, etc., use embedded systems. Some embedded systems also contain operating systems, but most embedded systems implement the entire control logic by a single program.
The widely accepted definition of embedded system in China is: application-centered, computer technology-based, software and hardware can be tailored to meet the strict requirements of application system on function, reliability, cost, volume, power consumption, etc. The core of an embedded system consists of one or several microprocessors or single-chip processors that are pre-programmed to perform a few tasks. Unlike common computers that can run user-selected software, software on embedded systems is usually temporarily unchanged; So it is often referred to as firmware.
Linux is a free and open source Unix-like operating system. There are many different versions of Linux, but they all use the Linux core. Linux can be installed on a variety of computer hardware devices, such as mobile phones, tablets, routers, video game consoles, desktops, mainframes and supercomputers. Linux is a leading operating system and the 10 fastest supercomputers in the world run on it. Strictly speaking, the term Linux itself only refers to the Linux core, but actually people have become accustomed to using Linux to describe the entire Linux-based core and to using GNU to engineer tools and databases for operating systems.
Linux is a set of free-to-use and free-spread Unix-like operating system. It is a multi-user, multi-task, multi-threaded and multi-CPU operating system based on POSIX and UNIX. It runs the major UNIX tool software, applications, and network protocols. It supports 32-bit and 64-bit hardware. Linux inherits Unix network-centric design idea and is a stable multi-user network operating system. It is mainly used on the computer based on Intel x86 series CPU. This system is designed and implemented by thousands of programmers around the world. The goal is to create Unix compatible products that are free to use around the world and are not subject to copyright restrictions on any commercialized software.
Linux is known for its efficiency and flexibility. The modular design structure of Linux enables it to run on expensive workstations as well as realize all Unix features on inexpensive PC computers with the capability of multi-task and multi-user. Linux is freely available under GNU public license and is a POSIX compliant operating system. The software package of Linux operating system includes not only the complete Linux operating system, but also the application software such as text editor and high-level language compiler. It also includes an X-Windows graphical user interface with multiple window managers that allow us to operate the system using windows, icons and menus, just as we do with Windows NT.
Embedded Linux system is to apply it to embedded system by utilizing many characteristics of Linux itself. With the emergence of microprocessors, low-cost, compact CPU and peripheral connections provide a stable and reliable hardware architecture, so the bottleneck restricting the development of embedded systems is highlighted in software. Although some embedded operating systems have appeared since the end of the 1980s, the more famous ones are Vxwork, pSOS, Neculeus and Windows CE. But these proprietary operating systems are commercial products whose high prices keep many small companies away from low-end products. Moreover, source code closure greatly limits developer motivation. In addition, in combination with domestic facts, the current country’s strong support for the autonomous operating system also provides a broad development prospect for the promotion of LINUX with open source. Also, for the upper application developers, an embedded system requires a highly concise, user-friendly, reliable, widely used, easily developed, multi-tasked and inexpensive operating system. In the near future, processors will be built into everything from refrigerators to radios. Because of the openness of Linux, many people think it is very suitable for most Internet devices. They believe that Linux supports different devices and different configurations.
The advantages of Linux as an embedded system are firstly that it is open source and does not have black box technology. Many Linux enthusiasts all over the world are powerful technical support of Linux developers. Secondly, the core of Linux is small and efficient, and the update speed of the core is very fast. Third, Linux is a free OS that is very competitive in price.
Linux also has many features needed by embedded operating system. The outstanding feature is that it is a cross-platform system which is suitable for many CPUs and hardware platforms. So far, it can support twenty or thirty CPUs. In addition, it has stable performance, good tailoring, easy development and use. Many CPUs, including household electrical chips, have started to migrate Linux platforms. Porting is much faster than the Java development environment. That is, if you develop your product in a Linux environment today, you won’t have any problems changing CPUs in the future. At the same time, the structure of the Linux core is very complete in the aspect of network. Linux supports the most common TCP/IP protocol in the network. Provides support for Ethernet networks including 10, 100, and gigabytes, as well as wireless networks, Toker ring, optical fibers and even satellites. So Linux is very suitable for the development of information appliances.
There are also a growing number of developers using Linux to develop wireless connection products. A very important advantage of Linux in the rapidly growing home field of wireless connection applications is that it develops fast enough. This is because LInux has many tools and Linux is familiar to many programmers. Therefore, we need to use the Linux operating system in the embedded system.
The size of Linux makes this easy due to the modularity, adaptability and configurability inherent in the embedded operating system, Linux. In addition, the practicability of the Linux source code and the eagerness of thousands of programmers to use it in countless embedded applications have led to the emergence of many embedded Linux, including Embedix, ETLinux, LEM, Linux Router Project, LOAF, uCLinux, muLinux, ThinLinux, FirePlug, Linux and PizBox Linux.