# lyos

**Repository Path**: jimxue/lyos

## Basic Information

- **Project Name**: lyos
- **Description**: 微内核类Unix操作系统内核，支持x86/x86_64，arm64和RISC-V
- **Primary Language**: C
- **License**: GPL-3.0
- **Default Branch**: develop
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 68
- **Forks**: 12
- **Created**: 2015-03-29
- **Last Updated**: 2025-07-25

## Categories & Tags

**Categories**: os

**Tags**: None

## README

#+HTML:<div align=center>

* Lyos
#+HTML: <a href="https://ci2.jimx.codes/job/lyos/"><img src="https://ci2.jimx.codes/buildStatus/icon?job=lyos"></a>

#+HTML: <a href="https://ci2.jimx.codes/job/lyos-nightly/"><img src="https://ci2.jimx.codes/buildStatus/icon?job=lyos-nightly"></a>

#+HTML: <a href="https://github.com/Jimx-/lyos"><img alt="screenshot" src="https://i.imgur.com/pSLgqXh.png"></a>

#+HTML:</div>


Lyos is an open source microkernel multitasking operating system, it runs
on 64-bit x86-based PCs. It is distributed under the GNU General Public License.

** Trying out Lyos
To try out Lyos without building the whole system, you can download a xz-compressed [[https://lyos.jimx.codes/nightly/lyos-i686.img.xz][nightly image]], uncompress the image and run it with QEMU:

#+BEGIN_SRC shell
qemu-system-x86_64 -smp 2 -drive id=hda,file=lyos-i686.img,format=raw,if=none -device virtio-blk-pci,drive=hda -m 2048 -serial stdio -vga virtio -display sdl -cpu host,pmu=true --enable-kvm  -netdev user,id=net0,hostfwd=tcp::5555-:22 -device virtio-net,netdev=net0
#+END_SRC

** Features
Lyos has many standard features:

- Microkernel
  + Kernel only handles message passing, interrupts and task scheduling, other things like reading/writing files, memory managing and device operations are handled by servers.
  + Servers are single executables(not modules) that are loaded by kernel at boot time, running in user privilege level and their own address space.
- Multitasking
  + BFS scheduler
- Symmetric multiprocessing
- ELF loading
- Interprocess Communication
  + Servers and user programs communicate using fixed length message(80 bytes)
  + Interrupts are converted into messages and sent to userspace servers
  + Unix signals
- Virtual file system
  + Ext2 filesystem support
  + procfs, sysfs, ...
- Userspace
  + Newlib
  + GCC, binutils, bash, ...
  + [[https://github.com/wayland-project/weston][Weston]] Wayland's reference compositor

** Building Lyos
*** Preparation
First we will clone the repository into the ~lyos~ directory:
#+BEGIN_SRC shell
git clone https://github.com/Jimx-/lyos.git
cd lyos
#+END_SRC

Since Lyos requires various build-time dependencies, it is recommended to set up a Docker instance as the build environment to make sure the correct versions of these dependencies are installed:
#+BEGIN_SRC shell
docker build -t lyos_build .
#+END_SRC

After building the Docker image, start a container:
#+BEGIN_SRC shell
docker run -v $PWD:/workspace/lyos -it lyos_build
#+END_SRC

If everything is set up properly, you should see the bash prompt and a ~lyos~ directory under ~/workspace~ containing the source files in the repository:
#+BEGIN_SRC shell
root@2519c5bdfad9:/# ls /workspace
lyos
#+END_SRC

Now you can switch to the ~/workspace/lyos~ directory and proceed to the Building section.
#+BEGIN_SRC shell
cd /workspace/lyos
#+END_SRC

Alternatively, you can install the dependencies manually if you prefer to build Lyos on the host system directly. The complete list of required dependencies is in ~Dockerfile~. You can install the dependencies with a standard package manager (e.g. ~apt~ on Ubuntu).

*** Building
Make sure that you are in the root directory of this repository (~/workspace/lyos~ if you are using a Docker container). First we need to create the build configuration file and install some userspace headers to the cross-compile system root:
#+BEGIN_SRC shell
make <SUBARCH=x86_64> defconfig objdirs install-headers
#+END_SRC
The optional ~SUBARCH~ environment variable specifies which architecture to build Lyos for. Currently only ~x86_64~, ~i686~ and ~riscv64~ are supported. If not specified, Lyos will be built for the architecture of the host system.

Set up the toolchain and userspace packages for building Lyos:
#+BEGIN_SRC shell
cd toolchain
./download.sh
BUILD_EVERYTHING=true ./setup.sh <-m x86_64>
cd ..
#+END_SRC
Similar to ~SUBARCH~, the ~-m~ option of ~setup.sh~ specifies the architecture to build the toolchain and packages for.

Now build the kernel and servers:
#+BEGIN_SRC shell
make SUBARCH=x86_64

#+END_SRC
(Optionally) ~setup.sh~ only builds some core userspace packages like ~bash~ and ~coreutils~. You still need to build some extra packages if you want to use graphical interface:
#+BEGIN_SRC shell
cd toolchain
BUILD_EVERYTHING=true ./setup-x11.sh -m x86_64
BUILD_EVERYTHING=true ./setup-extra.sh -m x86_64
cd ..
#+END_SRC

*** Creating Disk Image
Now you can create the disk image for Lyos:
#+BEGIN_SRC shell
sudo ./scripts/setup-disk.sh
#+END_SRC
This will create a disk image ~lyos-disk.img~ under the current directory which can be launched with QEMU.