Toy minimal micro-kernel OS for education demo. Single-threaded, simple custom filesystem, bootloader support. No network. Just a hobby teaching toy OS.
- What Is This
- Features
- Tech Stack
- Directory Structure
- Build & Run
- Web Demo
- Known Limitations
- Learning Value
- Documentation
- License
TurboxOS is a minimal micro-kernel operating system built for educational purposes. It is not a production system, not a Unix clone, not a performance benchmark. It exists to answer one question:
What happens between pressing the power button and seeing a shell prompt?
Every layer is implemented from scratch, with readability prioritized over performance.
| Feature | Description |
|---|---|
| Micro-kernel Structure | Kernel only keeps process, IPC, scheduling, memory. Filesystem runs as a separate service process |
| Cooperative Scheduling | Single-threaded, no preemption, processes are coroutines |
| Bitmap Physical Allocator | 4KiB pages, first 1MiB reserved, double-free detection |
| Free-list Heap Allocator | First-fit with block splitting and adjacent coalescing |
| Custom Filesystem | TurboxFS: static file table, create/write/read/run/list |
| Bootloader Support | Two-stage boot, real mode → protected mode → C++ kernel |
| System Call Layer | int 0x80 trap, unified ABI, user-side API wrappers |
| IPC | Simplified Minix-style rendezvous, single-word mailbox |
| Web Terminal | Browser-based terminal emulator with dual-mode sync/fallback |
| Layer | Tech | Responsibility |
|---|---|---|
| boot | NASM assembly | Real-mode boot, A20, GDT, protected-mode jump |
| kernel | C++ / assembly | Process, IPC, scheduling, syscall dispatch |
| mm | C++ | Physical page allocator, kernel heap |
| fs | C++ | Memory filesystem + mini script interpreter |
| drv | C++ | VGA text output, PS/2 keyboard |
| hal | C++ | Hardware abstraction + PIT timer |
| middle | C++ | VFS adapter + IPC filesystem service |
| user | C++ | Shell and demo user programs |
| tools | Python | Build scripts, image packing, data bridging |
| web | HTML/CSS/JS | Terminal emulator |
TurboxOS/
├── boot/ # Boot sector and loader
├── drv/ # Device drivers
├── fs/ # TurboxFS memory filesystem
├── hal/ # Hardware abstraction layer
├── hw/ # GDT/IDT/ports
├── kernel/ # Micro-kernel core
├── middle/ # VFS and IPC adapter
├── mm/ # Memory management
├── runtime/ # Custom string/memory functions
├── syscall/ # System call wrappers
├── tools/ # Build and bridge tools
├── user/ # Shell and demo programs
├── web/ # Web terminal
└── linker.ld # Linker script
- NASM
- i686-elf cross-compilation toolchain (gcc/g++/ld)
python tools/build.py
python tools/pack_image.pyOutputs: turbox.bin kernel binary, turbox.img bootable image.
qemu-system-i386 -fda turbox.imgAfter boot, you'll enter a shell. Type help to see available commands.
You can try the terminal without booting the kernel:
python tools/bridge.py --demoThen open web/index.html in a browser. The terminal supports create, write, run, ls, cat commands, emulating TurboxFS.
- No network
- No preemptive scheduling
- No user/kernel address space isolation
- No disk filesystem
- No graphical interface
- Physical memory capped at 64MiB
- File table fixed at 64 files, max 4096 bytes per file
These are deliberate teaching trade-offs, not bugs.
This project walks through the core path of an operating system:
BIOS → bootloader → protected mode → C++ kernel → process
→ IPC → filesystem → user program
Each layer keeps only the minimal implementation. Code is readable, auditable, and easy to experiment with. Suitable for:
- Understanding x86 boot flow
- Understanding micro-kernel and Minix-style IPC
- Understanding memory management and heap allocation
- Understanding system calls and user API design
- Understanding filesystem abstraction
- SPEC.md — Complete system specification
教学演示用的微型内核操作系统。单线程，极简自定义文件系统，支持引导加载。无网络。只是一个兴趣向的教学玩具 OS。
TurboxOS 是一个为教学目的而写的微型内核。它不是生产系统，不是 Unix 克隆，也不是性能测试。它只回答一个问题：
从按下电源键到看到 shell 提示符，中间发生了什么？
每一层都从零实现，可读性优先于性能。
| 特性 | 说明 |
|---|---|
| 微内核结构 | 内核只保留进程、IPC、调度、内存。文件系统作为独立服务进程运行 |
| 协作式调度 | 单线程，无抢占，进程即协程 |
| 位图物理页分配器 | 4KiB 页，前 1MiB 保留，带双重释放检测 |
| 空闲链表堆分配器 | 首次适配，支持块分裂和相邻合并 |
| 自定义文件系统 | TurboxFS：静态文件表，支持 create/write/read/run/list |
| Bootloader 支持 | 两阶段启动，实模式 → 保护模式 → C++ 内核 |
| 系统调用层 | int 0x80 陷入，统一 ABI，用户态 API 封装 |
| IPC | 简化版 Minix 风格 rendezvous，单字信箱 |
| Web 终端 | 浏览器终端模拟器，支持同步/回退双模式 |
| 层 | 技术 | 职责 |
|---|---|---|
| boot | NASM 汇编 | 实模式引导，A20，GDT，保护模式跳转 |
| kernel | C++ / 汇编 | 进程、IPC、调度、系统调用分发 |
| mm | C++ | 物理页分配、内核堆 |
| fs | C++ | 内存文件系统 + mini 脚本解释器 |
| drv | C++ | VGA 文本输出、PS/2 键盘 |
| hal | C++ | 硬件抽象 + PIT 定时器 |
| middle | C++ | VFS 适配 + IPC 文件系统服务 |
| user | C++ | Shell 和 demo 用户程序 |
| tools | Python | 构建脚本、镜像打包、数据桥接 |
| web | HTML/CSS/JS | 终端模拟器 |
TurboxOS/
├── boot/ # 引导扇区和加载器
├── drv/ # 设备驱动
├── fs/ # TurboxFS 内存文件系统
├── hal/ # 硬件抽象层
├── hw/ # GDT/IDT/端口
├── kernel/ # 微内核核心
├── middle/ # VFS 和 IPC 适配
├── mm/ # 内存管理
├── runtime/ # 自研字符串/内存函数
├── syscall/ # 系统调用封装
├── tools/ # 构建和桥接工具
├── user/ # Shell 和 demo
├── web/ # 网页终端
└── linker.ld # 链接脚本
- NASM
- i686-elf 交叉编译工具链（gcc/g++/ld）
python tools/build.py
python tools/pack_image.py产物：turbox.bin 内核二进制，turbox.img 启动镜像。
qemu-system-i386 -fda turbox.img启动后进入 shell，输入 help 查看命令。
不启动内核也能体验终端：
python tools/bridge.py --demo然后打开 web/index.html。浏览器里的终端支持 create、write、run、ls、cat 等命令，模拟 TurboxFS。
- 无网络
- 无抢占式调度
- 无用户态/内核态地址空间隔离
- 无磁盘文件系统
- 无图形界面
- 物理内存上限 64MiB
- 文件表固定 64 个文件，单文件最大 4096 字节
这些都是刻意的教学取舍，不是缺陷。
这个项目完整走了一遍操作系统最核心的路径：
BIOS → bootloader → 保护模式 → C++ 内核 → 进程
→ IPC → 文件系统 → 用户程序
每一层都只保留最小实现，代码可读、可审计、可实验。适合：
- 理解 x86 启动流程
- 理解微内核和 Minix 风格 IPC
- 理解内存管理和堆分配
- 理解系统调用和用户 API 设计
- 理解文件系统抽象
- SPEC.md — 完整系统规范
保持好奇，保持学习。理解底层，才能走得更远。