xv6-public
penpot
xv6-public | penpot | |
---|---|---|
25 | 227 | |
7,408 | 28,134 | |
1.3% | 7.0% | |
0.0 | 10.0 | |
5 days ago | 3 days ago | |
C | Clojure | |
GNU General Public License v3.0 or later | Mozilla Public License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
xv6-public
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Challenging projects every programmer should try
+1 for mini operating system.
Us, application developers, rely on many OS features: memory management, filesystem, etc. I'm sure eventually we'll ask "how such things are done behind the scene?"
That's why I tinker with xv6 (https://github.com/mit-pdos/xv6-public) during sparetime. Learning various process scheduling algorithms from textbook is a thing. Implementing it is another thing. I learn a lot. And it's definitely fun, even though there's almost zero chance the knowledge gained is relevant for my job (I'm a mobile app dev).
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xv6 compile error
Recently I compiled xv6 using gcc 7.5.0 on Ubuntu 18 , everything is ok. But when I try to compile it using gcc 13.2.1 on latest Arch, it's failed: result
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How could the early Unix OS comprise so few lines of code?
https://github.com/mit-pdos/xv6-public has under 10,000 lines of C and assembly including some user space programs.
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The rxv64 Operating System: MIT's xv6, in Rust, for SMP x86_64 machines
xv6 was originally written for 32-bit x86; the RISC-V port is a relatively recent development. See e.g. https://github.com/mit-pdos/xv6-public for some of the earlier history.
rxv64 was written for a specific purpose: we had to ramp up professional engineers on both 64-bit x86_64 and kernel development in Rust; we were pointing them to the MIT materials, which at the time still focused on x86, but they were getting tripped up 32-bit-isms and the original PC peripherals (e.g., accessing the IDE disk via programmed IO). Interestingly, the non sequitur about C++ aside, porting to Rust exposed several bugs or omissions in the C original; fixes were contributed back to MIT and applied to the original (and survived into the RISC-V port).
Oh, by the way, the use of the term "SMP" predates Intel's usage by decades.
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Some were meant for C [pdf]
I'd define an arena as the pattern where the arena itself owns N objects. So you free the arena to free all objects.
My first job was at EA working on console games (PS2, GameCube, XBox, no OS or virtual memory on any of them), and while at the time I was too junior to touch the memory allocators themselves, we were definitely not malloc-ing and freeing all the time.
It was more like you load data for the level in one stage, which creates a ton of data structures, and then you enter a loop to draw every frame quickly. There were many global variables.
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Wikipedia calls it a region, zone, arena, area, or memory context, and that seems about right:
https://en.wikipedia.org/wiki/Region-based_memory_management
It describes history from 1967 (before C was invented!) and has some good examples from Apache ("pools") and Postgres ("memory contexts").
I also just looked at these codebases:
https://github.com/mit-pdos/xv6-public (based on code from the 70's)
https://github.com/id-Software/DOOM (1997)
I looked at allocproc() in xv6, and gives you an object from a fixed global array. A lot of C code in the 80's and 90's was essentially "kernel code" in that it didn't have an OS underneath it. Embedded systems didn't run on full-fledges OSes.
DOOM tends to use a lot of what I would call "pools" -- arrays of objects of a fixed size, and that's basically what I remember from EA.
Though in g_game.c, there is definitely an arena of size 0x20000 called "demobuffer". It's used with a bump allocator.
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So I'd say
- malloc / free of individual objects was NEVER what C code looked like (aside from toy code in college)
- arena allocators were used, but global vars and pools are also very common.
- arenas are more or less wash for memory safety. they help you in some ways, but hurt you in others.
The reason C programmers don't malloc/free all the time is for speed, not memory safety. Arenas are still unsafe.
When you free an arena, you have no guarantee there's nothing that points to it anymore.
Also, something that shouldn't be underestimated is that arena allocators break tools like ASAN, which use the malloc() free() interface. This was underscored to me by writing a garbage collector -- the custom allocator "broke" ASAN, and that was actually a problem:
https://www.oilshell.org/blog/2023/01/garbage-collector.html
If you want memory safety in your C code, you should be using ASAN (dynamically instrumented allocators) and good test coverage. Arenas don't help -- they can actually hurt. An arena is a trivial idea -- the problem is more if that usage pattern actually matches your application, and apps evolve over time.
- Run Linux Programs on DOS
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The Magma operating system
Magma is proudly licensed under the MIT license, and uses code from Xv6 and Yagura.
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User Space vs Kernel Space Development (For an experienced Dev)
My OS classes used xv6, a reimplementation of Unix Version 6 for a RISC-V architecture. Accompanying that was the OSTEP textbook.
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MINIX is an awesome way to learn a wide range of CS concepts
Check out xv6 if you are only getting started with operating systems and want something simpler.
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I am getting an undefined reference despite including the source file when compiling
Here is kernel.ld.
penpot
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Release Radar · April 2024 Edition: Major updates from the open source community
Imagine designers and coders working seamlessly together. That's what Penpot aims to do. It's a tool where designers can create stunning designs, interactive prototypes, and design systems at scale. Developers then have ready-to-use code, which makes their workflows faster and more efficient. Penpot's latest version receives a new grid CSS layout, new UI, new components system, and more components. Oh and there's now light AND dark mode 🎉.
- Figma OSS Alternative
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Rama is a testament to the power of Clojure
This is how I see things also. Clojure is extremely practical and naturally attracts people that want to ship products.
The "Figma OSS Alternative" post that's also on the HN homepage right now doesn't mention Clojure anywhere (no comments about it either!), but Penpot is clearly also yet another app successfully shipped using Clojure: https://github.com/penpot/penpot
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Penpot 2.0 Released
Really neat. I was mainly curious to know when they are planning to release the self hosted docker versions of Penpot 2.0. Looks like its coming in the next couple days hopefully [1].
[1]: https://github.com/penpot/penpot/issues/4380
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What Design Tool Should I Use?
Website • Getting Started • User Guide • Tutorials & Info • Community • Twitter • Instagram • Mastodon • Youtube
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15 open-source tools to elevate your software design workflow
Link | Free Trial | Github | License
- Ask HN: How would you build Figma?
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Open Source alternatives to tools you Pay for
Penpot - Open Source Alternative to Figma
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CEO of Figma is a Zionist and supports the occupation of Palestine
- Penpot (open source) - penpot.app/
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Just paying Figma $15/month because nothing else fucking works
A colleague had a quick presentation on Penpot[1] a few weeks back. Was a real contender I think.
[1]: https://penpot.app/
What are some alternatives?
xv6-riscv - Xv6 for RISC-V
pencil - The Pencil Project's unique mission is to build a free and opensource tool for making diagrams and GUI prototyping that everyone can use.
homebrew-i386-elf-toolchain - Homebrew formulas for buildling a valid GCC toolchain for the i386-elf target.
Tkinter-Designer - An easy and fast way to create a Python GUI 🐍
minixfromscratch - Development and compilation setup for the book versions of MINIX (2.0.0 and 3.1.0) on QEMU
excalidraw - Virtual whiteboard for sketching hand-drawn like diagrams
foam3 - FOAM: Feature-Oriented Active Modeller, Version 3 (unstable)
drawio-desktop - Official electron build of draw.io
stumpwm - The Stump Window Manager
Taiga - Agile project management platform. Built on top of Django and AngularJS
lispe - An implementation of a full fledged Lisp interpreter with Data Structure, Pattern Programming and High level Functions with Lazy Evaluation à la Haskell.
Akira - Native Linux App for UI and UX Design built in Vala and GTK