ProcessA process is an instance of an application. Each process has its own independent execution context and resources, such as a virtual address space. Practical operating systems provide the execution context as a separate concept called a "thread". For simplicity, in this book we'll treat each process as having a single thread.   Process control block The following process structure defines ..

Memory AllocationBefore implementing a memory allocator, let's define the memory regions to be managed by the allocator . = ALIGN(4); . += 128 * 1024; /* 128KB */ __stack_top = .; . = ALIGN(4096); __free_ram = .; . += 64 * 1024 * 1024; /* 64MB */ __free_ram_end = .;} This adds two new symbols,  __free_ram and __free_ram_end. This defines a memory area after the stack space. ..

ExceptionException is a CPU feature that allows the kernel to handle various events, such as invalid memory access (aka. page faults), illegal instructions, and system calls.  Exception is like a hardware-assisted try-catch mechanism in C++ or Java. Until CPU encounters the situation where kernel intervention is required, it continues to execute the program. The key difference from try-catch is ..

Kernel PanicA kernel panic occurs when the kernel encounters an unrecoverable error, similar to the concept of panic in Go or Rust. Have you ever seen a blue screen on Windows? Let's implement the same concept in our kernel to handle fatal errors. The following PANIC macro is the implementation of kernel panic#define PANIC(fmt, ...) \ do ..

C Standard LibraryIn this chapter, let's implement basic types and memory operations, as well as string manipulation functions. In this book, for the purpose of learning, we'll create these from scratch instead of using C standard library. The concepts introduced in this chapter are very common in C programming, so ChatGPT would provide solid answers. If you struggle with implementation or under..

Say "hello" to SBI- SBI is an "API for OS". - To call the SBI to use its function, we use the ecall instruction#include "kernel.h"extern char __bss[], __bss_end[], __stack_top[];struct sbiret sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long fid, long eid) { register long a0 __asm__("a0") = arg0; register long a1 __asm__("a1") = arg1; ..

2024. 01. 13. Monday 우선 프로젝트를 원격으로 연결해두었다. :) GitHub Desktop 앱도 오랜만에 들어가본다 , , https://github.com/SohyeonKim-dev/OperatingSystem GitHub - SohyeonKim-dev/OperatingSystem: OS 만들기 프로젝트OS 만들기 프로젝트 . Contribute to SohyeonKim-dev/OperatingSystem development by creating an account on GitHub.github.com          👩‍💻 brew로 qemu 설치 brew install llvm lld qemu     Let's boot OpenSBI     OpenSBI: Open Sourc..

2025. 01. 10 Friday 어제 Geek News에서 재미있어 보이는 프로젝트를 찾게 되었다.!     👩‍💻제대로 된 코딩을 한 게 . . 지난 겨울 방학때 한창 앱 개발하던 그 시절이 마지막인 것 같거등요 ^^.. ...💥무언가 만들고 싶은게 있어서,파바박 밤새 개발하던 때가 그립기도 하고,, 요즘은 하고 싶은 일보다 해야하는 일을 더 많이 하게 되는 것 같네요 ..   .·⋆(⌒_⌒)⋆·.          https://operating-system-in-1000-lines.vercel.app/en/ Intro | OS in 1,000 Lines operating-system-in-1000-lines.vercel.app세상에는 대단한 개발자가 너무너무많으셔 -              ..

2024. 10. 22 TuesdayVisualizatinon - Text memory + CPU Cycle    # Summary 정적으로 컴파일 된 코드 -> objdump로 확인 동적으로 연결 -> 코드 상에서 프린트 찍어서 확인 동적이냐 정적이냐 구분해서 분석하는 것 중요DLL이랑은 다른 내용 Rust 코드에서 print 구문으로 text 주소 확인하기 16진수 메모리 -> 100 단위도 매우 큰 scale csv 파일 -> Python으로 시각화 at Web - Plotly    https://plotly.com/python/ PlotlyPlotly'splotly.com  https://github.com/plotly/plotly.py GitHub - plotly/plotly.py: The in..

https://stackoverflow.com/questions/32026456/how-can-i-specify-an-area-of-code-to-instrument-it-by-pintool How can i specify an area of code to instrument it by pintool?There are four levels of granularity in Pin: routine, instruction and image, trace. Can i specify an limits/area to start and stop inserting instrumentation code. may by like directive like ( # startstackoverflow.com      # 자주 썼던..