PA2: System Call System calls are interfaces that allow user applications to request various services from the operating system kernel. This project aims to explore and understand how system calls are implemented in the xv6 operating system.git-hub: https://github.com/snu-csl/os-pa2/ 📌 start.cxv6 kernel boot up code 리눅스 커널의 초기화 과정을 담당 커널이 부팅될 때 가장 먼저 실행되어, 초기 환경을 설정#include "types.h"#include..

4.3 Context SwitchingThe kernel switches among threads in an effort to share the CPU effectively; this activity is called context switching. When a thread executes for the duration of its time slice or when it blocks because it requires a resource that is currently unavailable, the kernel finds another thread to run and context switches to it. The system can also interrupt the currently executin..

Run-Time OrganizationThe kernel can be logically divided into a top half and a bottom halfThe top half of the kernel provides services to processes in response to system calls or traps. This software can be thought of as a library of routines shared by all processes. The top half of the kernel executes in a privileged execution mode, in which it has access both to kernel data structures and to t..

3.1 Kernel OrganizationThe FreeBSD kernel can be viewed as a service provider to user processes. Processes usually access these services through system calls. Some services, such as process scheduling and memory management, are implemented as processes that execute in kernel mode or as routines that execute periodically within the kernel.In this chapter, we describe how kernel services are provi..