Privilege level, whether the CPU or the operating system manages it

The management of the processor boils down to the management of the process.

It has two privilege levels (also known as two rings) of 0 and 3

The components in Ring 0 are the underlying layers of the operating system, including support for low-level internal memory management, and the software in Ring 0 is the most powerful in the entire system, including almost all microprocessor instructions and access to key data structures such as page tables. Therefore, the software in ring 0 is the most reliable.

Rings are also called hierarchical protection domains, and some are also called user modes. It is a mechanism to protect data and block malicious behavior (keeping your computer safe). The computer's operating system provides resources with different levels of privilege access.

There are 4 levels of privilege level, privilege level.

Only privilege level 0 and privilege level 3 are used in Windows. The highest privilege is generally privilege level 0, which can directly manipulate hardware, such as CPU and memory. Typical operating systems and drivers run at this level.

Privilege level 3 is used by general programs and can invoke basic CPU instructions. Instructions at privilege level 0 cannot be invoked at privilege level three, and if they are called, they are displayed as invalid instructions.

The concept of privilege is used to protect the computer, and some dangerous instructions can only be executed by the operating system, preventing ordinary programs from abusing the resources of other programs. For example, if spyware wants to turn on the camera, it must ask the driver of privilege level 0 to turn it on, otherwise it will not be allowed.

Privilege sets are an important part of instruction set architectures and are a mechanism to protect data and block malicious behavior.

That is, the right click has a "run as administrator", which is the privilege level.

The five major functions of an operating system are the processor.

Management, storage management, device management, file management, and job management.

1. Processor management.

The most basic function of processor management is to handle interrupt events, and once the operating system is configured, various events can be handled. Another function of processor management is processor scheduling, which adopts different scheduling strategies for different situations.

2. Memory management.

Memory management mainly refers to the management of internal memory. The main task is to allocate memory space, ensure that the storage space occupied by each job does not contradict, and ensure that each job does not interfere with each other in its own storage area.

3. Equipment management.

Device management refers to the management of various peripheral devices, including allocation, startup, and troubleshooting. The main task is that when the user uses an external device, it must be requested, and it can only be used after the operating system has been uniformly assigned.

4. Document management.

File management refers to the management of information resources by the operating system. In the operating system, the part of the administrative information that is responsible for accessing is called the file system. File management supports operations such as storing, retrieval, and modifying files, as well as file protection functions.

5. Operation management.

Each user requests a computer system to complete a separate action called a job. Job management includes the input and output of jobs, and the scheduling and control of jobs, which control the operation of jobs according to the needs of users.

And then there's processor management.

The five major functions of the operating system are processor management, memory management, device management, file management, and job management.

In order to make the computer system work coordinatedly, efficiently and reliably, and also to give users a convenient and friendly environment to use the computer, in the computer operating system, there are usually functional modules such as processor management, memory management, equipment management, file management, and job management, which cooperate with each other to jointly complete all the established functions of the operating system.

The five functions of the operating system include: process and processor management, job management, storage management, device management, and file management.

The function of the operating system is mainly embodied in the management of the five major computer resources of computer resources, microprocessor, memory, peripheral equipment, files and jobs, and the operating system sets this management function into the corresponding program management module respectively, and each management module is in charge of a certain function. That is, the five major functions of the operating system.

a) Processor Management.

The most basic function of processor management is to handle interrupt events. The processor can only detect and produce interrupt events, and cannot process them. After the operating system is configured, all types of events can be processed.

Another feature of processor management is processor scheduling. The processor can be one or more, and different types of operating systems will have different scheduling strategies for different situations.

b) Memory management.

Memory management mainly refers to the management of memory. The main task is to allocate memory space, ensure that the storage space occupied by each job does not conflict, and that each job does not interfere with each other in its own storage area.

3) Equipment management.

Device management refers to the management of various peripherals, including allocation, booting, and troubleshooting. The main task is this: when a user uses an external device, they must make a request that the operating system be uniformly assigned before use.

When a user's program runs using a peripheral, the operating system is responsible for driving the peripheral. The operating system also has the ability to handle peripheral interrupt requests.

4) Document management.

File management refers to the management of information resources by the operating system. In an operating system, the part of the administrative information that is responsible for access is called the file system. A file is an ordered collection of logically complete collections of related information, each with a file name.

File management supports the storage, retrieval, and modification of files, as well as the protection of files. Operating systems typically provide powerful file systems, and some also provide database systems for information management.

5) Business management.

Each user requests an independent operation that is done by a computer system known as an operation. Job management includes job input and output, job scheduling, and control.

(1) Operation management: including tasks, interface management, human-computer interaction, graphical interface, voice control and virtual reality, etc.;

2) Document management: also known as information management;

3) Storage management: the essence is the management of storage "space", mainly referring to the management of main memory;

4) Equipment management: the essence is the management of hardware equipment, including the allocation, start-up, completion and ** of input and output equipment;

5) Process management: It is essentially the management of "time" performed on the processor, that is, how to allocate the CPU to each task really and reasonably.

Operating system (OS) is a computer program that manages and controls computer hardware and software resources, and is the most basic system software that runs directly on "bare metal", and any other software must be supported by the operating system to run.

The operating system is the interface between the user and the computer, as well as the interface between the computer hardware and other software. The functions of the operating system include managing the hardware, software and data resources of the computer system, controlling the operation of programs, improving the human-computer interface, providing support for other application software, maximizing the use of all resources of the computer system, providing various forms of user interface, enabling users to have a good working environment, and providing necessary services and corresponding interfaces for the development of other software.

In fact, the user does not need to touch the operating system, the operating system manages the computer hardware resources, and at the same time allocates resources according to the resource requests of the application, such as: dividing CPU time, opening up memory space, calling printers, etc.

The operating system has five main functions:

1. Processor management: mainly control and manage the work of the CPU.

2. Storage management: mainly for memory allocation and management.

3. Equipment management: mainly manage basic input and output devices.

4. File management: responsible for the organization, storage, operation and protection of computer files.

5. Process management: also known as job management, refers to the management of the operations carried out by the computer.

In "Run", enter Open Group Policy, select -- Computer Configuration -- Windows Settings -- Security Settings -- Local Policies -- User Rights Assignment -- Change System Time -- Local Security Settings -- Add Users or Groups, select users in the object, and add your current users to them.

Do the following: Click Run in the Start menu--- enter the policy group--- click Windows Settings--- Security Settings--- Local Policies--- User Assignment Entitlements--- double-click to change the system time.

Click Add Users and Groups--- Point Object Type--- Put the built-in security principle, users and groups are marked with a check point to determine--- solve the computer name of your computer (if you can't find it, you can basically not choose) --Fall back and select the user and group that option Point Advanced --- Point Find Now--- a whole bunch of users and groups will appear below (this is the key)--Select administrators, click OK--- and then find a user, This user is the name of the user you log in to the system and want to change the time.,Normally it should be in the immediate search.,The last one in the user.。 After selecting these two users, confirm the exit and restart the machine, and the time should be changed.

The CPU cache stores the data and instructions that the CPU is most likely to use in the near future, and the corresponding algorithms are required to determine which instructions and data enter the cache.

The BOIS motherboard can be set up. It is best not to modify it, as changing the value to a smaller value will affect the performance of the computer.

The lowest level of the computer is the hardware, and the hardware keeps running from the moment it is turned on. It's the kernel that's directly aimed at the hardware, but it's generally binary and can't be understood. Then use scripts to deal with it at the upper level of the kernel, which is **.

It is also difficult for non-professionals. Well, turning a program into a script for a certain function is a bunch of written ** to implement this function. You just need to enter some key information.

It still doesn't look comfortable, the graphical interface, the graphics card will beautify those things, so that you can see more comfortably in the display. In fact, whether it is in a marquee with a background and a dot label next to it, or a pure command line, it is necessary to type the keyboard or mouse on the screen coordinates to obtain information. This implementation process will not be described.

In short, the Windows operating system is such a full graphic, and Linux has a command line and also supports graphics. Then a bunch of things add up to the operating system. This kind of description is very unprofessional, you have to read books to be professional, and it is not enough to ask a few questions.