Front

OS là gì?

Back

Là phần mềm trung gian giữa người dùng và phần cứng, quản lý tài nguyên hệ thống.

Front

• User Mode vs Kernel Mode:

Back

• User Mode: hạn chế quyền truy cập phần cứng.

• Kernel Mode: toàn quyền truy cập tài nguyên hệ thống.

Front

System call

Back

Cơ chế gọi dịch vụ của OS fork(), read(), write().

Front

What is an Operating System (OS)?

Back

An operating system is a system program that acts as an intermediary between the user and the computer hardware.

It manages hardware resources such as CPU, memory, and I/O devices, and provides an interface so application programs can operate efficiently and safely.

Front

User Mode vs. Kernel Mode

Back

• User Mode: Limited access to hardware; cannot directly interact with critical system memory or devices.

• Kernel Mode: Full access to all system resources; only OS code runs in this mode.

 

Front

What is a System Call?

Back

A system call is a mechanism that allows a user program to request services from the operating system.
Examples: fork(), read(), write(), open(), exec(), exit().

Process:
User calls → Trap (software interrupt) → Kernel handles the request → Control returns to user mode.