The computer system hierarchy bare metal, window operating system, qq,
Operating system (os) refers to the hardware and software resources control and management of computer systems and computer rational organization of work and allocation schedule resources, to provide convenience to users and other software interfaces and environment, are the most basic computer systems software.
Management software for hardware management
Functions and objectives
Function as a resource manager provides the processor, memory functions, file management, device management target efficiency, safety
Added: process is the execution of a program, before executing the program needs to be put into memory, in order to be processed by the CPU
With the process of QQ video chat with friends:
step1: Found QQ installation positions (e.g. D: / Tencent / QQ / Bin) in the respective folders (folders opened layer by layer, the location to which the program is QQ.exe)
step2: Double-click to open the QQ (the need to process the relevant data into the memory)
step3: QQ program running (corresponding to the process is processed processors)
step4: start a video chat with friends (needs to be allocated to the process camera equipment)
As an interface between the user and the computer hardware
Command Interface: allows users to directly use
Interface: program allows the user to indirectly through
GUI: modern operating system is the most popular graphical user interfaces
Note: The system calls = = generalized system call command instruction
GUI: Graphical user interface, the user can use the image of a graphical interface to operate without the need to memorize complex commands, parameter.
Examples: Windows operating system, deleting a file just need to drag and drop files to the Recycle Bin
As the closest to the hardware level
Functions and objectives need to provide: an extension to the hardware of the machine to achieve
No software support computer called bare metal. On bare metal operating system installed can provide a user-friendly resource management and service functions, will be transformed into a bare metal
More powerful, easier to use the machine.
Usually covers software called machine expansion machine, also known as virtual machine
Analogy: Hardware: hammer, saw, wood, nails, operating system: good carpenter
Extended operating system to the hardware of the machine: good carpenter by these simple materials can be organized into a house, Sailing
Knowledge Review
operating system
Work computer resources concepts (definitions) 1. Coordination is responsible for managing hardware, software, etc. 2. 3. Provide a simple service for the upper user, the application is a software system
1. The management target functions and resources management processor 1.1 1.3 1.2 Memory Management File Management 1.4 Management Device
2.向用户提供服务 2.1命令接口 联机命令接口、脱机命令接口
2.2程序接口 由一组系统调用组成
2.3GUI图形用户界面