The role of operating systems in managing computer devices

• Basic principles of building an OS .
• 1.1. Frequency principle
• 1.2. The principle of modularity.
• 1.3. The principle of functional selection.
• 1.4. Principle of OS generation.
• 1.5. The principle of functional redundancy .
• 1.6. The principle of standard states (by default).

• 1.7. The principle of displacement.
• 1.8. The principle of virtualization.
• 1.9. The principle of software independence from external devices.
• 1.10. Principle of proportionality (compatibility).
• 1.11. The principle of openness and inclusion.
• 1.12. The principle of mobility (portability).
• 1.13. Safety principle.

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Frequency principle.

software algorithms, it is based on the separation of operations and sizes in processed arrays according to their frequency of use. To ensure faster access to frequently used operations and data, they are placed in operational memory. The main means of such access is the organization of multi-level scheduling.

Modularity principle .

reflects the technological and operational characteristics of the system . If this principle is inherent in both the OS, applications, and hardware, then maximum efficiency of use is achieved. achieved

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Modularity principle

The system technological and exploitation to do properties reflection brings

Privileged

again

incoming

renewable

.....

privileged in mode works ( interruptions) will be deleted ) ҳ explanations consecutively​​ does not change

many times , parallel use ( disconnection) no )

many once , repeatedly , interruption other issues to work will be lowered

Functional selection principle

This principle involves separating modules that must be permanently in memory in order to increase computing performance. This part of the OS is called the kernel.

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The principle of generating OS

This principle defines

functional redundancy .

This principle takes into account the possibility of performing the same task with different tools. The OS includes several different monitors that manage resources and several systems and libraries that manage files .

The principle of displacement.

This principle assumes that the execution of modules does not depend on their location in memory . The text of a module is adjusted to its location in memory by special mechanisms, or during its execution.

The principle of virtualization

This system uses a single centralized schema to describe the system structure as a set of process planners (schedulers) and resource allocators (monitors).

The principle of software independence from external devices .�

This principle is based on the fact that the connection of a program to a specific device is made not at the level of translation of the program, but at the time of its use. When programs work on new devices, they do not need to be recompiled. This principle is implemented in many operating systems.

Principle of proportionality

This principle states that software (SD) created for one OS can be run on other OSs and earlier versions of that OS.

The principle of openness and inclusion .

Openness implies that not only system specialists but also users have access to analysis. It allows for the addition of additional capabilities, the addition of new modules to the OS, and the modification of existing ones.

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The principle of mobility (transferability).

This principle implies the possibility of porting an OS from one platform to another type of platform.

Safety principle.

It protects one user's resources from another user, and protects the entire system from being occupied by only one user. In addition, this principle also includes protection against unauthorized access.

Security principle

One user resources other from users protection

Resources according to quota installation

Orajevaya kniga - safety about standards 1998​ USA

Systems 7​ security divided

D – the most lower level

C 1

C 2

B1

B 2

B3

A most protected class

Category S 2 typical features

• Confidential input tools , user identification provides
• The application selectively control to do
• Audit tools – events to list to take
• Memory again from use before initialization to do