Operating system design goals
1. Convenience
provides a user interface to make computer systems more convenient to use
2. effectiveness
be improved through effective management and distribution of software and hardware resources and rational organization of work processes computer resource utilization, improve system throughput
3. scalability
to adapt the rapid development of computer hardware and architecture of the higher performance and higher functionality and performance requirements of the corresponding
4 open
adaptation network integration and interoperability with different manufacturers and different types of computer equipment, to achieve the application portability and interoperability (and edit can run into the linux system on windows system too can run and edit)
The role of the operating system
An interface between (1) the user and the computer hardware system
Command mode (operating system shell)
- Intended for general audiences
- Command Line / menu-driven / command scripted / Graphical User Interface
- Offers users a convenient way to use a computer
The system is called (the operating system kernel)
- For application developers
- Formally similar procedure calls, programming used
- The basic mechanism to access operating system services
(2) computer system resource manager
Management Objects
- The processor, memory, peripherals, and information (software and data)
Content Management
-
Allocation of resources, recycling and access operations
-
The current state record of resources (quantity and usage), there will be a table record, the corresponding management strategies (sharing, protection and user rights)
(3) for the expansion of the machine (or virtual machine)
At first bare metal is not fully functional, the effect is not strong, installed after Caozuoxitong function more comprehensive
add on bare metal processor management, storage management, device management, file management, job management, graphical user interface and other functions, the computer system significantly enhanced functionality, more convenient to use
Composition and hierarchy of the operating system
- User Interface : command interface, program interface, graphical user interface
- Software manipulation and management of a collection of objects : processor / memory / device / file / job management software
- Operating system objects : processor, memory, devices, files and application
Definitions and examples of the operating system
**定义**：操作系统是最基本（重要）的系统软件，是一组有效管理和控制计算机硬件和软件资源、合理地对各类作业进行调度以组织和控制系统工作流程，并方便用户使用计算机的程序的集合
Operating system instance
Android is still the underlying Linux system IOS is based on the MAC OS
