Introduction to the concept and features of the embedded Linux operating system

Introduction to the concept and features of the embedded Linux operating system

Author: Wei Min Source: Automated Expo Release Date: 2005.01.24

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Introduction Application-centered, computer technology-based, software and hardware can be tailored to the application system's dedicated computer system with strict requirements on functions, reliability, cost, volume, and power consumption, it is called an embedded system. The basic components of a minimal embedded system are: ① An available facility (Tool) for guidance; ② a Linux microkernel with memory management, process management, and timer services; (3) An initial process; (4) hardware driver; (5) one or several application processes to provide necessary application functions. Features of Embedded Linux • Comparison Some people think that Linux is too big to be used as an embedded system, which is incorrect. There are many Linux Release versions for PC, which are not available at all, or even exceed the needs of a PC user. Therefore, a practical embedded operating system can be formed by rationally cutting Linux. The comparison between the embedded Linux operating system and the dedicated embedded real-time operating system is as follows. • Memory usage in Embedded Linux In a simple system, after the system is started, the kernel and various application processes reside in the memory. This is the way most traditional embedded systems work, including Linux. But it can also use another method: Linux has the ability to load and uninstall programs, all applications are stored in the Flash file system as files and loaded into the memory as necessary to save Ram. • Debugging methods for developing embedded Linux When developing an embedded Linux system for a new hardware, the sequence and steps of the typical debugging tools to be used are as follows: ① Modify the code to enable reading and writing the serial port and run the program using GDB. This will allow it to communicate with another Linux host that is running the gdb program. GDB sessions the gdb target code on the test computer through the serial port and provides all the C source code-level debugging information; ② Execute the remaining hardware and software initialization code with GDB until the Linux kernel begins to take over; ③ Once the Linux kernel is started, the above serial port becomes the Linux Console port, which can be used for subsequent development, and the gdb kernel debugging version kgdb can be used. • Portability of Embedded Linux Porting linux to a new microprocessor system is fast. Generally, it is transplanted to a new type of target board, which contains unique peripherals. Most of the kernel code is the same, because they have nothing to do with the microprocessor, so the porting work is mostly concentrated on some memory management and interrupt processing programs. Once completed, they will be very stable. Embedded Linux applications Embedded systems cover a wide range of fields, including information appliances such as set-top boxes, digital TVs, visual telephones, and home networks. The industrial market includes industrial control equipment and instruments; the commercial market includes handheld computers, thin clients, and POS terminals. The communication market includes WAP mobile phones and wireless PDAs. Currently, the information home appliance market is widely favored. Many domestic development vendors are increasing investment, developing and developing new products. Embedded Linux will be their preferred operating system.