CrisOS v2 is an experimental, freestanding 32-bit operating system built from scratch in C and Assembly for the i386 architecture. It boots via GRUB using the Multiboot standard, initializes a protected-mode kernel, and drops into a Linux-like interactive shell — all without any standard library dependency. Whether you’re studying OS internals, hardware initialization, or kernel design patterns, CrisOS v2 provides a readable, well-structured codebase to learn from and extend.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/CRISTOP-bot/cris-os-v2/llms.txt
Use this file to discover all available pages before exploring further.
Introduction
Understand what CrisOS v2 is, what it includes, and how its modules fit together.
Quickstart
Build the kernel, generate the ISO, and boot CrisOS v2 in QEMU in minutes.
Architecture
Explore the boot sequence, protected mode setup, GDT, IDT, and kernel entry point.
Shell Commands
Full reference for every built-in shell command — file I/O, system info, and more.
What’s Inside
CrisOS v2 is organized as a collection of independent kernel subsystems, each implemented in dedicated C source files.Virtual File System
A tree-based in-memory VFS with custom CRFS flat-image rootfs support.
Interactive Shell
A built-in shell with ~25 Linux-like commands and output redirection.
Service Manager
An init-style service manager that parses unit files at boot.
Drivers
PS/2 keyboard (US/ES/DE), mouse, PIT timer, PIC, and VGA console drivers.
LCP Package Manager
A dual-mode package manager: in-kernel C version and host-side Python CLI.
Kernel API Reference
C function signatures for the VFS, string utilities, assembly routines, and allocator.
Get Up and Running
Install prerequisites
Install
gcc (i686-elf cross-compiler recommended), make, qemu-system-i386, and grub-mkrescue.CrisOS v2 is an educational project. It runs in 32-bit protected mode with no standard library. It is designed to be studied, extended, and experimented with — not for production use.