Linux is an embedded operating system, which can run on PDA, set-top box or game machine. And it can run on various hardware platforms, such as platforms with x86, 680x0, SPARC, Alpha and other processors.
Embeddedoperationsystem(EOS) refers to the operating system used in embedded system. Embedded operating system is a widely used system software, which usually includes hardware-related underlying driver software, system kernel, device driver interface, communication protocol, graphical interface, standardized browser and so on.
What is the startup process of embedded linux system?
1) Initialize RAM Because Linux kernel usually runs in RAM, Bootloader must set and initialize RAM before calling Linux kernel to prepare for calling Linux kernel. The tasks of initializing RAM include setting the control register parameters of CPU so that RAM can be used normally and detecting the size of RAM.
2) Initialization serial port plays a very important role in the startup process of Linux, and it is one of the ways for Linux kernel to interact with users. Linux can output information through serial port during the startup process, so that we can clearly understand the startup process of Linux. Although it is not a task that Bootloader must complete, outputting information through serial port is a powerful tool for debugging Bootloader and Linux kernel, so generally Bootloader will initialize a serial port as a debugging port when executing.
3) Detecting the processor type Bootloader must detect the processor type of the system before calling the Linux kernel, and save it in a constant and provide it to the Linux kernel. When the Linux kernel is started, it will call the corresponding initialization program according to the processor type.
4) Setting Linux startup parameters Bootloader must set and initialize Linux kernel startup parameters during execution.
5) Calling the Linux kernel image Bootloader is the last task to be completed. If the Linux kernel is stored in Flash and can run directly on it (Flash here means NorFlash), then it can jump directly into the kernel for execution. However, due to various restrictions on executing code in Flash, the speed is far less than that of RAM, so the general embedded system copies the Linux kernel into RAM, and then jumps to RAM for execution.
What is the major of embedded technology application?
Computer software science major. Embedded technology and application mainly learn the basic knowledge and skills of embedded technology and embedded product software development, and carry out the production, management and after-sales maintenance of embedded products. For example, the application and development of embedded technologies such as HDTV, routers and automotive electronics, and the production and testing of products such as mobile phone equipment software.
What does linux embedded development do?
The definition of embedded system is "a device used to control, monitor or assist the operation of machines and equipment" (formerly: a device controlled to control and monitor the operation of equipment, machines or plants). This is mainly defined from the application object, from which we can see that embedded system is a combination of software and hardware, and can also cover auxiliary equipment such as machinery.
It is generally believed in China that the embedded system is a special computer system which is application-centered, based on computer technology, and can be tailored in software and hardware to meet the strict requirements of the application system on function, reliability, cost, volume and power consumption.
Embedded mainly uses C language and C++, but JAVA is also used in embedded technology, mainly for embedded game development and mobile development. , focusing on the J2ME direction of Java.
The development prospect and employment prospect of embedded system are very good, but there is a shortage of talents in this field in China at present. So you'd better study this major.
Embedded system is mainly divided into three parts:
1. embedded Linux system development: focusing on development environment construction, kernel principle, cross-compilation, etc.
2. Embedded Linux application development: focus on Linux application programming, kernel compilation and system call.
3. Embedded Linux driver development: Focus on driver development and deeply analyze the kernel of embedded Linux system.
At present, there are many professional embedded training in the market, because it was developed in recent years. As far as I know, the most authoritative and professional is the Oriental Saifu Embedded Training College, which is located at the East Gate of Tsinghua and has a deep relationship with Tsinghua. Teachers, in particular, are the best in the whole embedded training field. 80% of the teachers come from Tsinghua University, Fortune 500 companies and top IT companies in China.
If time and economic conditions permit, the training is still very good, which can not only learn professional knowledge, but also solve the employment problem, and the employment unit is much better than you find! If you need training, they are the best choice!
How to develop programs in embedded linux operating system environment?
Due to the inherent advantages of LINUX, embedded development mostly adopts LINUX system:
1. Open source, open code, save the trouble of writing by yourself, save the cost, and do not involve patent and property rights disputes.
2. Full-featured, many hardware devices have rich drivers, which only need to be transplanted and do not need to be changed too much.
3. Stability, linux is indeed more stable than windows.
4. For most chips, there are customized configuration files. Under the Linux kernel source code, there are many chip configuration files in arch/arm/configs.
5. The concept of divide and rule is in 5. Linux can make drivers and applications develop in parallel and speed up development.