1. The operating system status
The computer system consists of hardware and software of two parts. Usually computer is not configured software called bare metal. Direct use of bare metal is not only inconvenient, but also seriously reduce the efficiency and utilization of the machine.
Operating system (OS, Operation System) in order to bridge the gap between man and machine, that in order to establish an interface between the user and the computer , and configure a system to bare metal software. As can be seen in the figure below, the operating system is the first layer of software on the bare metal, is a function of the hardware system of the first extension.
Configuring the target operating system:
1. The computer provides an interface between a user and the computer system hardware, computer system easier to use .
2. effectively control and manage hardware and software resources of the computer system, so as to obtain more efficient use .
3. The computer system of rational organization of work processes to improve system performance (e.g., response time, systems throughput, etc.).
4. comply with international standards, design and build an open environment that supports scalable architecture that supports interoperability and portability of applications.
Look at the operating system from a different angle characteristics
1. user point of view - Convenience : providing good, consistent user interface to differences in the type and number, make up the hardware system.
2. The system administrators view - Effectiveness : management and distribution of hardware and software resources , rational organization of the computer work processes .
3. Scalability : refers to the operating system to add new features can be easily, the other part of the enhanced functionality of the system caused by the changes to be as small as possible . I.e. scalability allows the operating system with minimal changes to the enhanced performance .
4. Portability : the development of hardware manufacturing standards quickly and often unpredictable, so the operating system must have good portability, the portability of the entire operating system with minimal changes to migrate to a different processor or computer on different configurations .
5. Compatibility : refers to software or hardware capabilities applicable to other (few) types of computer systems, designed to protect existing hardware and software resources, save development investment. Operating System Compatibility include binary compatibility and source-level compatible
Note:
Binary compatibility is an executable program in an operating system can directly run successfully on a different operating system, without having to recompile or establishment, modify the source code.
Source-level compatibility is a source of an operating system under after recompilation can successfully run on a different operating system, without having to re-prepare and modify the source code .