In-depth analysis and comparison of the three embedded operating systems

1. embedded systems and embedded operating systems 11 embedded systems are based on embedded computers, designed for users, products, applications, and software and hardware.

1. embedded systems and embedded operating systems

1.1 Embedded System

Embedded systems are based on embedded computers. they are user-oriented, product-oriented, and application-oriented, and their hardware and software can be reduced, it is applicable to specialized computer systems that have strict requirements on functions, reliability, cost, volume, power consumption, and other features.

Embedded systems have the following features: high reliability; the system can still work normally in harsh environments or when a sudden power failure occurs; many embedded applications require real-time performance, this requires the embedded operating system to have real-time processing capabilities. the embedded system and specific applications are organically combined, and its upgrading is also carried out in synchronization of specific products; software code in embedded systems requires high quality and high reliability, and is generally solidified in read-only memory or flash memory. that is to say, software requires solid-state storage instead of stored in disks and other carriers.

1.2 embedded operating system

The Embedded Operating System (EOS) is a widely used System software. in the past, it was mainly used in industrial control and defense systems. EOS is responsible for allocating and scheduling all software and hardware resources embedded into the system, controlling and coordinating concurrent activities. it must reflect the characteristics of the system, it can achieve the functions required by the system by loading and unloading certain modules. At present, we have launched some successful EOS product series. With the development of Internet technology, the popularization and application of information appliances, and the miniaturization and specialization of EOS, EOS began to develop from a single weak function to a highly specialized and powerful function. Embedded operating systems have outstanding features in real-time system efficiency, hardware dependence, software solidification, and application specialization. Compared with general operating systems, EOS has the following features in addition to the most basic functions of general operating systems, such as task scheduling, synchronization, interrupt processing, and File Processing:

① Maintainability. An open and scalable architecture.

② Strong real-time performance. EOS is generally highly real-time and can be used in various device controls.

③ Unified interface. Provides various device driver interfaces.

④ Easy to operate, simple, and friendly GUI and GUI.

⑤ Provides powerful network functions, supports TCP/IP and other protocols, supports TCP, UDP, IP, and PPP protocols, and provides unified MAC access layer interfaces, reserved interfaces for various mobile computing devices.

⑥ Strong stability and weak interaction. once an embedded system starts to run, there is no need for too much user intervention. This requires the system-managed EOS to be highly stable, user interfaces of embedded operating systems generally do not provide operation commands. they provide services to user programs through system calling commands.

7. fixed the code. in an embedded system, the embedded operating system and application software are solidified in the ROM of the embedded system computer. Auxiliary memory is rarely used in embedded systems. Therefore, the file management function of embedded operating systems should be easily disassembled and various memory file systems should be used.

Middleware provides better hardware adaptability, that is, good portability.

There are about 40 types of embedded operating systems used for information appliances internationally. Currently, the most popular EOS products on the market, including the Palm OS of 3Com subsidiaries, account for 50% of the world's share, microsoft's Windows CE is only 29%. in the U.S. market, Palm OS shares more than 80% of Windows CE. open-source Linux is suitable for the development of information appliances, for example: the Xlinux-based embedded operating system "quark" developed by Hongqi embedded Linux and meishang net Tiger developed by CKE Hongqi Software Technology Co., Ltd., which is currently the world's smallest Linux, it has two outstanding features: small size and GCS encoding.