Basic knowledge about operating system hardware

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Related Knowledge: digital logic circuit, computer composition principle, operating system

The switch is on, giving a certain voltage, power, 1.

The switch is in the off status, power-off, 0.

Memory, controller, memory, input device, and output device

The control bit is used to achieve line multiplexing, and registers are used to solve the data coverage problem caused by line multiplexing (temporary storage ).

ROM:

Ram: Memory

The interrupt mechanism solves the problem of CPU polling on Io devices, reducing the number of CPU interruptions and improving performance.

North Bridge (high-speed bus controller): Memory

The current memory directly transmits data with the CPU

Nanqiao (low speed bus controller): IO Device

Nanqiao connects to the CPU through beiqiao

SSD is directly connected to beiqiao to improve transmission speed.

The cache solves the problem that the CPU does not match the memory speed. The closer the cache is to the CPU, the smaller the capacity, the faster the speed, the higher the cost.

Principle of program locality: temporal locality and spatial locality (optimizable programs)

Machine language-assembly language-advanced language (uses the middle layer API to solve the differences between underlying chips)

Hardware architecture: Arm (Android, IOS), x86, x64, Anta, power, Alpha, ultraspace, m68000, m68k, powerpc

The production process for clock speed improvement has reached the bottleneck. At present, the CPU performance is improved by increasing the number of cores.

OS: wiindows, Linux, Unix

Manual Input and offline batch processing (TAPE)

CPU is divided into slice and memory segments

32-bit operating system supports up to 4 GB memory: virtual address space used for programming

The operating system is a set of general software, which is not responsible for specific work, but to coordinate the work.

The program must use the System Call (kernel) to operate the hardware and encapsulate the library generated after the system call.

Software-database-System Call-hardware

Shell: Human-Computer Interaction Interface (graphical GUI and command line cli), which translates human operations into commands that can be understood by machines.

Different shells implement the same functions, and the usage is similar.

The Linux learning curve is steep, intelligent, and stable.

Protection Mechanism: applications cannot access operating system segments in memory.

Power-on self-check-loading the Operating System (kernel space)-Applications

Program startup Methods: self-start and On-Demand startup

Kernel functions: process management, memory management, file system, network functions, hardware drivers, and security mechanisms