https://github.com/yhzhang0128/egos-2000
Envision a future where every student can read all the code of a teaching operating system.
https://github.com/yhzhang0128/egos-2000
education operating-system
Last synced: 1 day ago
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Envision a future where every student can read all the code of a teaching operating system.
- Host: GitHub
- URL: https://github.com/yhzhang0128/egos-2000
- Owner: yhzhang0128
- License: other
- Created: 2022-04-18T18:25:26.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2025-04-08T02:09:10.000Z (about 1 month ago)
- Last Synced: 2025-04-11T02:51:51.557Z (about 1 month ago)
- Topics: education, operating-system
- Language: C
- Homepage: https://egos.fun/
- Size: 24.8 MB
- Stars: 2,260
- Watchers: 32
- Forks: 163
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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- my-awesome - yhzhang0128/egos-2000 - system pushed_at:2025-04 star:2.3k fork:0.2k Envision a future where every student can read all the code of a teaching operating system. (C)
README
📢 [Feb 3, 2025] The first draft of the [EGOS book](https://egos.fun/book/overview.html) has been released which contains 9 course projects.
## Vision
This project's vision is to help **every** student read **all** the code of a teaching operating system.
With only **2000** lines of code, egos-2000 implements every component of a teaching operating system that runs on both QEMU and RISC-V boards.
The [EGOS book](https://egos.fun/book/overview.html) further contains 9 course projects based on egos-2000.
```shell
# The cloc utility is used to count the lines of code.
> cloc egos-2000 --exclude-ext=md,txt,toml,json # excluding text files
...
github.com/AlDanial/cloc v 1.94 T=0.05 s (949.3 files/s, 62349.4 lines/s)
-------------------------------------------------------------------------------
Language files blank comment code
-------------------------------------------------------------------------------
C 30 427 594 1594
C/C++ Header 9 66 106 256
Assembly 3 15 45 95
make 1 16 8 55
-------------------------------------------------------------------------------
SUM: 43 524 753 2000 (exactly!)
-------------------------------------------------------------------------------
```
## Earth and Grass Operating System
The **egos** part of egos-2000 is named after its three-layer architecture.
* The **earth layer** implements hardware-specific abstractions.
* tty and disk device interface
* timer and memory management interface
* The **grass layer** implements hardware-independent abstractions.
* process control block and system call interface
* The **application layer** implements file system, shell and user commands.
The definitions of `struct earth` and `struct grass` in header file [egos.h](library/egos.h) specify the layer interface.
Please read [USAGES.md](USAGES.md) for running egos-2000 and
the [instruction set manuals](https://github.com/riscv/riscv-isa-manual/releases) for the RISC-V privileged ISA.
## Acknowledgements
Many thanks to Meta for a [Facebook fellowship](https://research.facebook.com/blog/2021/4/announcing-the-recipients-of-the-2021-facebook-fellowship-awards/).
Many thanks to [Robbert van Renesse](https://www.cs.cornell.edu/home/rvr/), [Lorenzo Alvisi](https://www.cs.cornell.edu/lorenzo/), [Shan Lu](https://people.cs.uchicago.edu/~shanlu/), [Hakim Weatherspoon](https://www.cs.cornell.edu/~hweather/) and [Christopher Batten](https://www.csl.cornell.edu/~cbatten/) for their support.
Many thanks to [Cheng Tan](https://naizhengtan.github.io/) and [Yu-Ju Huang](https://yuju-huang.github.io/) for providing valuable feedback to the [EGOS book](https://egos.fun) and using egos-2000 in [Northeastern CS4973/6640](https://naizhengtan.github.io/25spring/) and [Cornell CS4411/5411](https://www.cs.cornell.edu/courses/cs4411/2025sp/).
Many thanks to [Haobin Ni](https://haobin.cx/) and [Hongbo Zhang](https://www.cs.cornell.edu/~hongbo/) for [porting egos-2000 to mriscv](https://github.com/0x486F626F/mriscv/tree/egos), a simple processor written in SystemVerilog.
Many thanks to [Brandon Fusi](https://www.linkedin.com/in/brandon-cheo-fusi-b94b1a171/) for [porting egos-2000 to Allwinner D1](https://github.com/cheofusi/egos-2000-d1) and Sipeed's [Lichee RV64 - Nezha compute module](https://wiki.sipeed.com/hardware/en/lichee/RV/RV.html).
For any questions, please contact [Yunhao Zhang](https://dolobyte.net/).