X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/74926d2db1d9f3228acdfca03013a8ba0ac1d8c0..1171754ec28161647e916c3339f8da3d1804e1be:/README.md

diff --git a/README.md b/README.md
index f1cf6b6..8135165 100644
--- a/README.md
+++ b/README.md
@@ -3,333 +3,438 @@
 </p>
 
 <p align="center">
-  <span>简体中文</span> | <a href="docs/README_en.md">English</a>
+  <a href="docs/README.cn.md">简体中文</a> | <a href="#the-lunaixos-project">English</a>
 </p>
 
-# LunaixOS Project
+# The Lunaix Project
+
+The Lunaix kernel (or soon-to-be LunaixOS) is a hobby kernel, started in 2022, 
+written entirely from scratch. With a big ambition of being POSIX-compliance, 
+and designed with performance and modernity in mind, with some independent 
+thoughts being applied in architectural design.
+
+
+This project is built entirely from first principles - meaning no code was 
+copy-pasted or recycled from other OS projects or tutorials. Lunaix didn't begin 
+as an attempt to outperform anything; it started as a personal challenge to 
+learn OS theory and explore advanced kernel features through original design 
+and implementation. Everything you see here was developed solo, part-time, 
+with only hardware specs and my beloved **Modern Operating Systems** as guidance.
+
+If you're a kernel hobbyist looking for a fresh take or tired of mass-produced, tutorial-style 
+projects, then welcome, you're in the right place!
+
+
+| ![showcase_lunaix-over-serial.png](docs/img/showcase_lunaix-over-serial.png) |
+|:--:|
+| *Lunaix over serial* (`console=/dev/ttyS0`) |
+
+| ![showcase_lunaix-over-serial.png](docs/img/showcase_lunaix-over-vga-text.png) |
+|:--:|
+| *Lunaix over VGA text mode* (`console=/dev/ttyVCON0`) |
+
+> By the way, do you know there is an online video course  by the author on the design of lunaix? [Check it out](https://space.bilibili.com/12995787/channel/collectiondetail?sid=196337) (although it is in Chinese!)
+
+## Features
+
+Lunaix is a multi-architecture, general-purpose kernel built with performance, 
+modularity, and robustness in mind. Its design emphasizes advanced abstractions, 
+proactive error detection, and subsystem isolation. Lunaix is
+
++ **Fully-preemptive** for responsive multi-tasking
++ **Modular** with compile-time configurable components and extensible 
+  subsystems
++ **High-performance**, leveraging modern caching strategies and efficient 
+  infrastructures.
++ **Fault-tolerant**, with built-in error handling and stack backtracing
++ **Robust by design**, using mechanisms like proactive deadlock detection 
+  and driver isolation
+
+A significant amount of effort has gone into crafting clean abstractions, 
+implementing advanced kernel features, and applying performance optimizations 
+throughout the system.
+
+To better illustrate the scope of work already done, the following non-exhaustive 
+list outlines currently supported features in Lunaix:
+
+### List of All Features
+<details>
+
+<summary>Click to Expand</summary>
+
++ Multi-ISA
+  + x86_32
+  + x86_64
+  + Aarch64 (WIP)
++ Boot protocol
+  + abstraction for different protocol
+  + configurable kernel boot-time parameters
++ Platform resource management and definition
+  + read-only ACPI table interpretation
+  + full devicetree implementation
++ Memory management
+  + architecture-neutral abstraction
+  + highmem
+  + copy-on-write
+  + page sharing
+  + explicit huge page
+  + on-demand paging
+  + compound page
+  + reverse mapping (rmap)
+  + memory compaction (WIP)
+  + slab-style object allocator
+  + inter-process address space access
++ Multi-tasking
+  + fully preemptive
+  + protection levels
+  + process isolation
+  + native threading
+  + signal mechanism
+  + round-robin scheduler (for now)
+  + kernel level multi-tasking (i.e. kernel threads)
+  + taskfs: file system interface to process and threads
++ File system
+  + POSIX-compliant interface
+  + virtual file system framework
+  + file system mounting mechanism
+  + page cache for file IO
+  + inode/dnode caching
+  + ext2 (rev.0, rev.1)
+  + iso9660 (rock-ridge)
+  + twifs: kernel state fs interface.
++ Device management and interrupt handling
+  + unified IRQ framework
+  + unified driver framework for heterogenous devices
+  + modular driver model allow compiled-time toggling
+  + asynchronous operation model supported
+  + devfs: device fs interface.
++ Block I/O (blkio)
+  + unified block IO interface
+  + IO request packets caching
+  + asynchronous IO operation
++ Serial I/O
+  + POSIX-compliant serial IO model
++ Caching Infrastructure
+  + LRU replacement policy and pooling
+  + kernel daemon for dynamic and transparent cache managements
++ Error handling and detection
+  + stack backtracing with symbol resolution
+  + stack unwinding for nested exception
+  + CPU state dumping
+  + deadlock/hung-up detection
+
+</details>
+
+### List of Built-in Drivers
+
+<details>
+
+<summary>Click to Expand</summary>
+
++ Architecture Neutral
+  + UART 16650-compatible driver
+  + Serial ATA AHCI
+  + PCI 3.0
+  + PCIe 1.1
+  + Standard VGA
++ Intel x86
+  + RTC (Intel PCH)
+  + IOAPIC IRQ controller
+  + APIC Timer
+  + Legacy i8042 keyboard controller
++ ARM
+  + GICv3
+  + PL011 (WIP)
+</details>
+
+## Documentations
+
+There are documentations avaliable if you want to dig deeper. Keep in mind they are still work in progress and missing localisation.
+
++ [Luna's Tour - Into Lunaix's Inner Workings](docs/lunaix-internal.md)
++ [Syscall Number Assignments](docs/lunaix-syscall-table.md)
+
+## Compile and Build
+
+Building lunaix is simple, no more bloated dependencies to install, basic 
+`build-essentials` installation plus a python are sufficient.
+
++ gcc (recommend v12+)
++ binutils
++ make
++ python (recommend v3.11+)
 
-LunaixOS - 一个简单的，详细的，POSIX兼容的（但愿！），带有浓重个人风格的操作系统。开发过程以视频教程形式在Bilibili呈现：[《从零开始自制操作系统系列》](https://space.bilibili.com/12995787/channel/collectiondetail?sid=196337)。
+And also one should have environment variable `ARCH=<arch>` exported, where 
+`<arch>` is one of the supported arhcitecture (`x86_32`, `x86_64`, `aarch64`).
 
-## 当前进度以及支持的功能
+For cross compilation, also export `CX_PREFIX` to the gcc prefix for the 
+corresponding `<arch>`.
 
-该操作系统支持x86架构，运行在保护模式中，采用宏内核架构，目前仅支持单核心。内存结构采用经典的3:1划分，即低3GiB为用户地址空间（0x400000 ~ 0xBFFFFFFF），内核地址空间重映射至高1GiB（0xC0000000 ~ 0xFFFFFFFF）。内存的详细布局可参考[LunaixOS内存地图](docs/img/lunaix-os-mem.png)
+The following `make` actions are then available to use.
 
-在下述列表中，则列出目前所支持的所用功能和特性。列表项按照项目时间戳进行升序排列。
+| Make command | Usage |
+| ---- | ---- |
+| `make all`               | Build the kernel bin |
+| `make rootfs`            | Build the stock rootfs |
+| `make clean`             | clean |
+| `make config`            | run configuration tool |
+| `make reconfig`          | revert to default and restart configuration |
 
-+ 使用Multiboot进行引导启动
-+ APIC/IOAPIC作为中断管理器和计时器
-+ ACPI
-+ 虚拟内存
-+ 内存管理与按需分页（Demand Paging）
-+ 键盘输入
-+ 多进程
-+ 50个常见的Linux/POSIX系统调用（[附录1](#appendix1)）
-+ 用户模式
-+ 信号机制
-+ PCI 3.0
-+ PCIe 1.1 (WIP)
-+ Serial ATA AHCI
-+ 文件系统
-  + 虚拟文件系统
-  + ISO9660
-    + 原生
-    + Rock Ridge拓展 (WIP)
-+ 远程GDB串口调试 (COM1@9600Bd)
+A successful build will give `build/bin/kernel.bin`.
 
-已经测试过的环境：
+> Please note: this is the kernel, not a bootable image, it require a bootloader 
+> to boot and specify the rootfs.
 
-+ QEMU (>=7.0.0)
-+ Bochs（SATA功能不支持）
-+ Virtualbox
-+ Dell G3 3779
+## Get Started
 
-## 目录结构
+If you are impatient, or just want something to run and don't want to went 
+through tedious process of configuring rootfs and tweak kernel parameters. You 
+can use the `live_debug.sh` provided in the lunaix root directory to quickly 
+bring up the system with default parameters (also used by the author for 
+debugging).
 
-|                                           |                              |
-| ----------------------------------------- | ---------------------------- |
-| [lunaix-os](lunaix-os/)                   | LunaixOS源代码               |
-| [slides](slides/)                         | 视频中所用的幻灯片和补充材料 |
-| [reference-material](reference-material/) | 标准，技术文档和参考文献     |
+### Quick Start
 
-## 编译与构建
+This will get you up and running real quick. We will use `x86_64` as example.
 
-构建该项目需要满足以下条件：
+Assuming a Linux or other Unix-like shell environment. We also expect you to be able to sort out trivial issues like missing packages.
 
-+ gcc (目标平台: i686-elf)
-+ binutils
-+ make
-+ xorriso
-+ grub-mkrescue
-
-**注意：gcc不能是本机自带的，必须要从源码编译，并配置目标平台为：`i686-elf`，以进行交叉编译。配置过程可参考[附录二：编译gcc作为交叉编译器](#appendix2)。**
-
-假若条件满足，那么可以直接执行`make all`进行构建，完成后可在生成的`build`目录下找到可引导的iso。
+**Select your target**
+```sh
+$ export ARCH=x86_64
+```
 
-本项目支持的make命令：
-| 命令                     | 用途                                            |
-| ------------------------ | ----------------------------------------------- |
-| `make all`               | 构建镜像（`-O2`，但禁用CSE相关的优化项 **※** ） |
-| `make instable`          | 构建镜像（`-O2`，开启CSE相关优化）              |
-| `make all-debug`         | 构建适合调试用的镜像（`-Og`）                   |
-| `make run`               | 使用QEMU运行build目录下的镜像                   |
-| `make debug-qemu`        | 构建并使用QEMU进行调试                          |
-| `make debug-bochs`       | 构建并使用Bochs进行调试                         |
-| `make debug-qemu-vscode` | 用于vscode整合                                  |
-| `make clean`             | 删除build目录                                   |
+**Check Python**
+```sh
+$ python --version
+```
 
-**※：由于在`-O2`模式下，GCC会进行CSE优化，这导致LunaixOS会出现一些非常奇怪、离谱的bug，从而影响到基本运行。具体原因有待调查。**
+Ensure at least `3.11`
 
-## 运行以及Issue
+**Check compiler**
+```sh
+$ gcc -dumpmachine
+```
 
-运行该操作系统需要一个虚拟磁盘镜像，可以使用如下命令快速创建一个：
+Ensure `x86_64-linux-gnu` or anything resemble `x86_64`
 
-```bash
-qemu-img create -f vdi machine/disk0.vdi 128M
+**Check QEMU**
+```sh
+$ which qemu-system-x86_64
 ```
 
-如果你想要使用别的磁盘镜像，需要修改`configs/make-debug-tool`
+Should display a valid installation path
 
-找到这一行：
+**Optional: Setting up Cross-Compiler**
 
+```sh
+$ export CX_PREFIX=x86_64-linux-gnu-
 ```
--drive id=disk,file="machine/disk0.vdi",if=none \
+
+**Run Configuration**
+```sh
+make config
 ```
 
-然后把`machine/disk0.vdi`替换成你的磁盘路径。
+Then hitting `q` in the interactive shell to accept default setting.
 
-有很多办法去创建一个虚拟磁盘，比如[qemu-img](https://qemu-project.gitlab.io/qemu/system/images.html)。
+**Build stock rootfs**
 
-在大多数情况下，我都会尽量保证本机运行无误后，push到仓库中。同时，该系统是经过虚拟机和真机测试。如果发现在使用`make all`之后，虚拟机中运行报错，则一般是编译器优化问题。这个问题笔者一般很快就会修复，如果你使用别的版本的gcc（笔者版本11.2），出现了此问题，欢迎提issue。请参考[附录3：Issue的提交](#appendix3)
+```sh
+make rootfs
+```
 
-下面列出一些可能会出现的问题。
+Note, this requires root for creating fs image. You can check script `lunaix-os/scripts/mkrootfs` if you feel uncertain.
 
-#### 问题#1： QEMU下8042控制器提示找不到
+**Build & Run**
+```sh
+./live_debug.sh
+```
 
-这是QEMU配置ACPI时的一个bug，在7.0.0版中修复了。
+you should see gdb now take control of your shell
 
-#### 问题#2：多进程运行时，偶尔会出现General Protection错误
+**Connect to serial via telnet**
 
-这很大概率是出现了竞态条件。虽然是相当不可能的。但如果出现了，还是请提issue。
+Open up another window or session
+```sh
+telnet localhost 12345
+```
 
-#### 问题#3：Bochs无法运行，提示找不到AHCI控制器
+**Commence simulation**
 
-正常，**因为Bochs不支持SATA**。请使用QEMU或VirtualBox。
+Back to the gdb session and type `c` to countine
 
-## 参考教程
 
-**没有！！** 本教程以及该操作系统均为原创，没有基于任何市面上现行的操作系统开发教程，且并非是基于任何的开源内核的二次开发。
+**Watch Lunaix booting!**
 
-为了制作LunaixOS，作者耗费大量时间和精力钻研技术文档，手册，理论书籍以及现行工业标准，从而尽量保证了知识的一手性。（这样一来，读者和听众们也算是拿到了二手的知识，而不是三手，四手，甚至n手的知识）。
+Congrats, enjoy your lunaix! (or submit an issue)
 
-大部分的文档和标准可以在上述的[reference-material](reference-material/)中找到。
 
-当然，您也可以参考以下列表来了解现阶段的LunaixOS都使用了哪些资料（本列表会随着开发进度更新）：
+### Not so Quick Start
 
-#### 手册，标准，技术文档
+Here is a slower and yet more verbose steps:
 
-+ [Intel 64 and IA-32 Architecture Software Developer's Manual (Full Volume Bundle)](https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html)
-+ [ACPI Specification (version 6.4)](https://uefi.org/sites/default/files/resources/ACPI_Spec_6_4_Jan22.pdf)
-+ IBM PC/AT Technical Reference
-+ IBM VGA/XGA Technical Reference
-+ 82093AA I/O Advanced Programmable Controller (IOAPIC) (Datasheet)
-+ MC146818A (Datasheet)
-+ Intel 500 Series Chipset Family Platform Controller Hub (Datasheet - Volume 2)
-+ PCI Local Bus Specification, Revision 3.0
-+ PCI Express Base Specification, Revision 1.1
-+ PCI Firmware Specification, Revision 3.0
-+ Serial ATA - Advanced Host Controller Interface (AHCI), Revision 1.3.1
-+ Serial ATA: High Speed Serialized AT Attachment, Revision 3.2
-+ SCSI Command Reference Manual
-+ ATA/ATAPI Command Set - 3 (ACS-3)
-+ [ECMA-119 (ISO9660)](https://www.ecma-international.org/publications-and-standards/standards/ecma-119/)
-+ Rock Ridge Interchange Protocol (RRIP: IEEE P1282)
-+ System Use Sharing Protocol (SUSP: IEEE P1281)
+1. Select an architecture `<arch>`
+2. Check the compilation prerequisites and presence of `qemu-system-<arch>`
+3. Optionally export `CX_PREFIX` if you are building for another architecture.
+4. Run `make ARCH=<arch> rootfs` to build stock rootfs image, require support 
+   of `dd`，`mkfs.ext2`, `mount -o loop`, `mktemp`.
+5. Run `ARCH=<arch> live_debug.sh` to boot in QEMU with gdb hooked (one should 
+   see a gdb session)
+6. telnet to `localhost:12345`, this is QEMU emulated serial port
+7. type `c` in the active gdb session and commence emulation.
+8. Congrats, enjoy your lunaix!
+(or submit an issue)
 
-**免责声明：PCI相关的标准最终解释权归PCI-SIG所有。此处提供的副本仅供个人学习使用。任何商用目的须向PCI-SIG购买。**
 
-#### 理论书籍
+## Booting the kernel
 
-+ *Computer System - A Programmer's Perspective Third Edition (CS:APP)* (Bryant, R & O'Hallaron, D)
-+ *Modern Operating System* (Tanenbaum, A)
-+ 《汇编语言》（王爽） - 用于入门Intel语法的x86汇编（对于AT&T语法，推荐阅读CS:APP）
-+ ~~《微机原理与接口技术》 - 用于大致了解x86架构的微机体系（更加细致的了解可以阅读Intel Manual）~~ （已过时，推荐阅读CS:APP）
-
-#### 网站
-
-+ [OSDev](https://wiki.osdev.org/Main_Page) - 杂七杂八的参考，很多过来人的经验。作者主要用于上古资料查询以及收集；技术文献，手册，标准的粗略总结；以及开发环境/工具链的搭建。
-+ [FreeVGA](http://www.osdever.net/FreeVGA/home.htm) - 98年的资源！关于VGA编程技术的宝藏网站。
-+ GNU CC 和 GNU LD 的官方文档。
-+ [PCI Lookup](https://www.pcilookup.com/) - PCI设备编号查询
-
-#### 其他
-
-+ Linux Manual - 用于查询*nix API的一些具体行为。
-
-## 附录1：支持的系统调用<a id="appendix1"></a>
-
-**Unix/Linux/POSIX**
-
-1. `sleep(3)`
-1. `wait(2)`
-1. `waitpid(2)`
-1. `fork(2)`
-1. `getpid(2)`
-1. `getppid(2)`
-1. `getpgid(2)`
-1. `setpgid(2)`
-1. `brk(2)`
-1. `sbrk(2)`
-1. `_exit(2)`
-1. `sigreturn(2)`
-1. `sigprocmask(2)`
-1. `signal(2)`
-1. `kill(2)`
-1. `sigpending(2)`
-1. `sigsuspend(2)`
-2. `read(2)`
-2. `write(2)`
-2. `open(2)`
-2. `close(2)`
-2. `mkdir(2)`※
-2. `lseek(2)`
-2. `readdir(2)`
-2. `readlink(2)`※
-2. `readlinkat(2)`※
-2. `rmdir(2)`※
-2. `unlink(2)`※
-2. `unlinkat(2)`※
-2. `link(2)`※
-2. `fsync(2)`※
-2. `dup(2)`
-2. `dup2(2)`
-2. `symlink(2)`※
-2. `chdir(2)`
-2. `fchdir(2)`
-2. `getcwd(2)`
-2. `rename(2)`※
-2. `mount(2)`
-2. `unmount` (a.k.a `umount(2)`)※
-2. `getxattr(2)`※
-2. `setxattr(2)`※
-2. `fgetxattr(2)`※
-2. `fsetxattr(2)`※
-2. `ioctl(2)`
-2. `getpgid(2)`
-2. `setpgid(2)`
-2. `mmap(2)`
-2. `munmap(2)`
-2. `execve(2)`※
-
-**LunaixOS自有**
-
-1. `yield`
-2. `geterrno`
-3. `realpathat`
-4. `syslog`
-
-( **※**：该系统调用暂未经过测试 )
-
-## 附录2：编译gcc作为交叉编译器<a id="appendix2"></a>
-
-注意，gcc需要从源码构建，并配置为交叉编译器，即目标平台为`i686-elf`。你可以使用本项目提供的[自动化脚本](slides/c0-workspace/gcc-build.sh)，这将会涵盖gcc和binutils源码的下载，配置和编译（没什么时间去打磨脚本，目前只知道在笔者的Ubuntu系统上可以运行）。
-
-**推荐**手动编译。以下编译步骤搬运自：<https://wiki.osdev.org/GCC_Cross-Compiler>
-
-**首先安装构建依赖项：**
-
-```bash
-sudo apt update &&\
-     apt install -y \
-        build-essential \
-        bison\
-        flex\
-        libgmp3-dev\
-        libmpc-dev\
-        libmpfr-dev\
-        texinfo
-```
+Since lunaix is a kernel, much like linux. It requires additional setup to do 
+the magic. And, as in "much like linux", methods to make linux kernel boot can 
+also apply to lunaix without or with little translation, as we will discuss 
+below.
 
-**开始编译：**
+The bootloader part is generic, any bootloader, for example GRUB will work (not 
+tested for UEFI, but I expect this would be an exception), or booting up in QEMU 
+using `-kernel` option
 
-1. 获取[gcc](https://ftp.gnu.org/gnu/gcc/)和[binutils](https://ftp.gnu.org/gnu/binutils)源码
-2. 解压，并在同级目录为gcc和binutil新建专门的build文件夹
+The kernel command line, is however, a bit differentiated.
+The syntax is similar, both takes form of space-separated array of `<key>=<val>` 
+pairs or boolean `<flag>`.
 
-现在假设你的目录结构如下：
+Currently, lunaix support the following options
 
-```
-+ folder
-  + gcc-src
-  + binutils-src
-  + gcc-build
-  + binutils-build
-```
+| Option | Default Value | Optional | Usage |
+| ------ | ----          |  -----   | ----  |
+| console | `/dev/ttyS0`   | No | Specify the system console device, path within lunaix's devfs |
+| rootfs | `/dev/block/sda` | No | Specify the device contain rootfs image, path within lunaix's devfs |
+| init | `/init` | Yes | Path within rootfs of the `init` |
+
+
+## Submit an Issue
 
-3. 确定gcc和binutil安装的位置，并设置环境变量：`export PREFIX=<安装路径>` 然后设置PATH： `export PATH="$PREFIX/bin:$PATH"`
-4. 设置目标平台：`export TARGET=i686-elf`
-5. 进入`binutils-build`进行配置
+If one ran into bug, one can submit an issue by filling up the following template
 
-```bash
-../binutils-src/configure --target="$TARGET" --prefix="$PREFIX" \
- --with-sysroot --disable-nls --disable-werror
 ```
+1. Describe the problem
+    "How does it look like, anything descriptive: visual, sonic, emotional experience"
 
-然后 `make && make install`
+2. Steps to reproduce
+    "How you ran into this mess?"
 
-6. 确保上述的`binutils`已经正常安装：执行：`which i686-elf-as`，应该会给出一个位于你安装目录下的路径。
-6. 进入`gcc-build`进行配置
+3. Expected behaviour
+    "What do you intended/expected to achieve/to be"
 
-```bash
-../gcc-src/configure --target="$TARGET" --prefix="$PREFIX" \
- --disable-nls --enable-languages=c,c++ --without-headers
+4. Lunaix's panic trace (if applicable)
+
+5. Other clues that you think might be helpful
 ```
 
-然后编译安装（取决性能，大约10~20分钟）：
 
-```bash
-make all-gcc &&\
- make all-target-libgcc &&\
- make install-gcc &&\
- make install-target-libgcc
-```
+## Limitations
+
+The development process is still in motion, any limitation can be categorised as 
+a feature yet to be. However, some features that the author considered to be the 
+most urgent and wish the matters to be discussed.
 
-8. 验证安装：执行`i686-elf-gcc -dumpmachine`，输出应该为：`i686-elf`
+Lunaix is under impression of uniprocessor and not capable of running in SMP 
+environment. This is major held back of being a modern operating system. It has 
+the highest priority among all other tasks
 
-**将新编译好的GCC永久添加到`PATH`环境变量**
+Lunaix do not have a mature (or even, an infant) user space ecosystem, mainly 
+because the lack of a proper and sophisticated libc. Efforts need to be done for 
+porting one to the target. However, given the author's tight schedule, this task 
+is unfortunately still beyond the horizon.
 
-虽然这是一个常识性的操作，但考虑到许多人都会忽略这一个额外的步骤，在这里特此做出提示。
+## Acknowledgement
 
-要想实现这一点，只需要在shell的配置文件的末尾添加：`export PATH="<上述的安装路径>/bin:$PATH"`。
+Albeit one must realise that the author has mentioned it in the very beginning, 
+the author would like to emphaise **again** on the nature of this project.
 
-这个配置文件是取决于你使用的shell，如zsh就是`${HOME}/.zshrc`，bash则是`${HOME}/.bashrc`；或者你嫌麻烦的，懒得区分，你也可以直接修改全局的`/etc/profile`文件，一劳永逸（但不推荐这样做）。
+As a personal challenge, this project is independently developed by the author 
+single-handly, which means:
 
-至于其他的情况，由于这个步骤其实在网上是随处可查的，所以就不在这里赘述了。
++ No reference to existing tutorials, books, online courses or any open source 
+  project that might provide any example, hint or working prototype on the 
+  design and implementation of kernel, subsystems or anythings that can be 
+  contributed towards a working prototype.
++ The author has no prior knowledge on Linux kernel through out 90% of the 
+  project time.
++ All knowledge on the kernel design is coming from the basic textbook on 
+  operating system theory, that is, *Modern Operating System* by Tanenbaum.
++ All knowledge on the system programming is coming from the basic textbook, 
+  that is, *Computer System - A Programmer's Perspective Third Edition*
++ All knowledge on the generic framework design and driver development are 
+  ingested from various technical specifications gathered across the Internet.
 
-## 附录3：Issue的提交<a id="appendix3"></a>
+## References
+
++ Intel 64 and IA-32 Architecture Software Developer's Manual (Full Volume Bundle)
++ ACPI Specification (version 6.4)
++ Devicetree Specification
++ ARM® Generic Interrupt Controller (v3)
++ Arm® Architecture Reference Manual (Profile-A)
++ Procedure Call Standard for the Arm® 64-bit Architecture (AArch64)
++ IBM PC/AT Technical Reference
++ IBM VGA/XGA Technical Reference
++ 82093AA I/O Advanced Programmable Controller (IOAPIC) (Datasheet)
++ MC146818A (Datasheet)
++ Intel 500 Series Chipset Family Platform Controller Hub (Datasheet - Volume 2)
++ PCI Local Bus Specification, Revision 3.0
++ PCI Express Base Specification, Revision 1.1
++ PCI Firmware Specification, Revision 3.0
++ Serial ATA - Advanced Host Controller Interface (AHCI), Revision 1.3.1
++ Serial ATA: High Speed Serialized AT Attachment, Revision 3.2
++ SCSI Command Reference Manual
++ ATA/ATAPI Command Set - 3 (ACS-3)
++ ECMA-119 (ISO9660)
++ Rock Ridge Interchange Protocol (RRIP: IEEE P1282)
++ System Use Sharing Protocol (SUSP: IEEE P1281)
++ Tool Interface Standard (TIS) Portable Formats Specification (Version 1.1)
++ *Computer System - A Programmer's Perspective Third Edition* (Bryant, R & O'Hallaron, D), a.k.a. CS:APP
++ *Modern Operating System* (Tanenbaum, A)
++ Free VGA, http://www.osdever.net/FreeVGA/home.htm 
++ GNU CC & LD online documentation.
++ PCI Lookup, https://www.pcilookup.com/
++ Linux man pages
 
-由于目前LunaixOS没有一个完善强大的内核追踪功能。假若Lunaix的运行出现任何问题，还请按照以下的描述，在Issue里面提供详细的信息。
+## Appendix 1: Supported System Call<a id="appendix1"></a>
 
-最好提供：
+Refer to [Lunaix Syscall Table](docs/lunaix-syscall-table.md)
 
-+ 可用于复现问题的描述和指引（如Lunaix运行平台的软硬件配置）
-+ 错误症状描述
-+ （如可能）运行截图
-+ 错误消息（如果给出）
-+ 寄存器状态的dump
-+ （如可能）提供错误发生时，EIP附近的指令（精确到函数）。如果使用`make all-debug`，会提供`build/kdump.txt`，你可以在这里面定位。或者也可以直接`objdump`
-+ （如可能）虚拟内存映射信息（QEMU下可使用`info mem`查看）。
+## Appendix 2: Debugging with GDB remotely via UART
 
-## 附录4：串口GDB远程调试
+**(((( Broken after a refactoring years ago, need rework ))))**
 
-LunaixOS内核集成了最基本的GDB远程调试服务器。可通过串口COM1在9600波特率上与之建立链接。但是，在将GDB与内核链接起来之前，还需要让内核处在调试模式下。
+<details>
+<summary> Click to expand </summary>
+The LunaixOS kernel comes with a built-in GDB debugging server, which runs on 
+COM1@9600Bd. However, LunaixOS must be in debug mode before involving GDB.
 
-要进入调试模式，需要往串口（波特率如上）写入字节串 `0x40` `0x63` `0x6D` `0x63`。此时，如果屏幕底部出现一条品红色背景的`DEBUG` 字样，那么就说明LunaixOS已处在调试模式下。
+One could trigger the debug mode by writing a byte sequence `0x40` `0x63` `0x6D` 
+`0x63`, to the same serial port. A text "DEBUG MODE" with magenta-coloured background shall be present at the bottom of the screen.
 
-注意，在这个时候，LunaixOS会开始在`COM1`上监听GDB协议信息，并且暂停一切的活动（如调度，以及对外部中断的一切响应）。用户此时需要将GDB与其挂载，并使用GDB的工作流来指示内核下一步的动作。
+Note that, whenever the text appears, the LunaixOS always halt all activities 
+other than the debugging server, which means no scheduling and no external 
+interrupt servicing. Users are now recommended to attach their GDB and drive 
+the kernel with the debugging workflow.
 
-在目前，为了防止代码过于臃肿，LunaixOS实现的是GDB远程协议要求的最小服务端命令子集：`g`, `G`, `p`, `P`, `Q`, `S`, `k`, `?`, `m`, `M`, `X`。足以满足大部分的调试需求。
+Currently, LunaixOS implements the required minimal server-side command subset 
+required by GDB Remote Protocol, namely, `g`, `G`, `p`, `P`, `Q`, `S`, `k`, `?`, 
+`m`, `M`, `X`. Which should be enough to cover most debugging activities.
 
-当结束调试的时候，请使用GDB的`kill`指令进行连接的断开。注意，这个指令会使得LunaixOS恢复所有暂停的活动，进入正常的运行序列，但并不会退出调试模式。GDB的挂载请求依然在LunaixOS中享有最高优先权。如果需要退出调试模式，需要往串口写入字节串：`0x40` `0x79` `0x61` `0x79`。
+When debugging is finished, one shall disconnect with `kill` command. This 
+command will not force LunaixOS to power down the computer, instead it just 
+resume the execution (identical behavior as `c` command). However, disconnecting 
+does not means exiting of debug mode. The debug mode is still actived and any 
+subsequent GDB attaching request shall remain the highest priority amongst all 
+other activity. One shall deactivate the debug mode by writing byte sequence 
+`0x40` `0x79` `0x61` `0x79` to the port, after GDB detached.
 
-### GDB调试注意事项
+### Limitations
 
-在调试中，请避免使用`info stack`，`bt`或者任何涉及 **栈展开（Stack Unwinding）** 或者 **栈回溯（Stack Backtracing）** 的指令。否则，LunaixOS很有可能会出现 **不可预料的行为** 。
+Currently, one should avoid the use of `info stack`, `bt` or any other command 
+that involves stack unwinding or stack backtracing. As it will somehow corrupt 
+the stack layout and result in undefined behaviour. This issue should be 
+addressed in future releases.
+</details>
\ No newline at end of file