What is best BSD system for learning how operating system work?

[HopingStar]

I don't know but choosing between FreeBSD, OpenBSD and NetBSD for a deep learning system and turn out, it is seem like a hard task for me.

It is hardly to tell what I want to aim because I don't like performance code, portable code or security code right now. I don't say it isn't important at all and I want to say thing I need right now is a great BSD system for learning how a operating system should work. Kinda ridicilous but I like simple code so that I can easily read it also it is must be good code so that I can improve my C knowledge how to write a great C code. I like clean base system.

One who know "how to drive car" but one who know "deeply about how many parts of the car have and how it will work". And I want to the the second guy.

If someone can explain me "why in some case portable, performance or security is important?" I would listen to your point of view since I am lack of knowledge
Maybe I would realize something and know how to choose thing clearly. :D

And I like networking through. But I am not sure which BSD have a great networking code. I am curious about it.

Also I am thinking of buying a 4.4BSD system design book, will that book have some knowledge that I can apply in modern BSD?

[jggimi]

Choose any of them. It doesn't matter which. Choose randomly, or choose the one with the best looking logo, or one with a Project website you prefer to use.

At this time you don't perceive that the differences between the OSes are important to you. So just pick one of them, and start your personal journey with it.

[shep]

Another tact is to peruse the handbook or FAQ's. You will invariably run into an issue and having official, up to date guides is priceless. With that in mind, here is my take:

FreeBSD Handbook: Easily the largest but some sections are out of date. For example, in setting up the sound card, the handbook still has you load a kernel module but since release 10, the most common sound drivers are statically compiled in the kernel. Also look at the FreeBSD Forums. What is not in the handbook can often be answered there.

OpenBSD FAQ: Succinct but updated for each new release. The OpenBSD section of this forum is the most active.

NetBSD Guide: Voluminous and even more out of date than FreeBSD. For example, section IV on setting up networking does not have any guidance on setting up Wifi with WPA2. You can find several ways to do it with a web search. To my knowledge, the NetBSD section in this forum is the only forum available and you can see with a glance it is not very active.

[vns3]

I am not sure what you mean by "deep learning" but I find that the whole OpenBSD ecosystem is much easier to navigate than the other 2. Another poster mentioned that their documentation is succinct and I find this to be on of the best features of the platform. It has been my experience that if i can't get what I need out of OpenBSD's man pages + FAQ, then it is most likely that I am missing some general knowledge in the technology space, not really having to do with the OS itself. In other words it seems like their documentation is written with the assumption that the reader has some knowledge of whatever topic it is already, and if I am not getting what I need from them, then I need to go out and learn more generic info about the topic at hand.

Also it seems to me that in OpenBSD there is an attempt to narrow the options for any particular type of software down to one or two "blessed" ways of doing things. This is helpful to me, because I tend to waste a lot of time, just looking at all the options, when trying out new technologies, and getting overwhelmed by the amount of options one has when working with FOSS.

I also appreciate the "sane defaults" concept that the OpenBSD developers have taken. I appreciate the fact that I can install it as a server or on my laptop and have a functioning device with very little configuration.

That being said, on my hardware, both FreeBSD and NetBSD are both faster that OpenBSD, but this difference gets smaller with each release of Open.

It seems like to me that on the FreeBSD, and NetBSD platforms there is more possibility available. For example I were going to deploy a product or try to get some not supported software to run on BSD I would chose one of those two, but if I am just needing a network node, or an OS for my laptop, I almost always chose Open.

So after much rambling, I would suggest OpenBSD as you are going to get a more streamlined system, and like I said i am not sure what you are trying to do, but you will will have less to wade through with Open, and up to date docs.

[IdOp]

My take on reading the first post is that the OP wants mainly to learn about OS programming and design by studying the source code.

[HopingStar]

Hmm, I think I understand something a little bit about thing happen in here. It would be better if I can learn operating system when they have enough documentation.

I don't think this isn't the only netbsd forum. I think I see others too like unitedbsd. But again, I still think that one who start with netbsd will have a lot of problems since netbsd lack of documentation and much stuff. Even sometimes, the less active of community make me feel like I have been left behind.

I appreciate that NetBSD still have their good point since it is pretty easy to work at lower level and tinker with your new kind of hardware to make it work. But again this operating system is not for a person who don't have enough knowledge. Maybe I will try to learn it again someday when I have enough knowledge about C.

FreeBSD and OpenBSD are good at documentation.
But I don't think I like FreeBSD when I don't have any purpose on it. Especially, I interest in sndio than OSS.
And I don't have reason to use ZFS. Urgh, I don't like Linux but I have to learn it instead of BSD system when I learn in my college.

I like OpenBSD because their FAQ tell me enough thing that I need to learn and understand. Well, I will let my feet wet with OpenBSD before looking for others system.

Problem is solved. OpenBSD I choose you.

And I think I should get a 4.4BSD design implement book. It will be better as a reference for how old school BSD work.

[Sehnsucht94]

Originally Posted by shep

NetBSD Guide: Voluminous and even more out of date than FreeBSD. For example, section IV on setting up networking does not have any guidance on setting up Wifi with WPA2.

That's succintly but clearly covered in 24.2.1. Connecting using IEEE 802.11 (Wi-Fi)

To my knowledge, the NetBSD section in this forum is the only forum available and you can see with a glance it is not very active.

In the last couple of years UnitedBSD has become by far the most active user forum in regard of NetBSD topics

[hitest]

Originally Posted by HopingStar

I like OpenBSD because their FAQ tell me enough thing that I need to learn and understand. Well, I will let my feet wet with OpenBSD before looking for others system.

Problem is solved. OpenBSD I choose you.

Good choice! I've used FreeBSD on and off since 5.x, NetBSD occasionally in VMs, and OpenBSD since 5.0. I appreciate the accurate documentation in OpenBSD.
This is my go to forum for all things related to OpenBSD. I'm no expert; I like and use OpenBSD. Thankfully this forum is populated with seasoned OpenBSD system administrators. I'm grateful for the kind help I've received here.

[Carpetsmoker]

I've gotten some good mileage at looking at some of the *ancient* Unix source code: https://github.com/dspinellis/unix-history-repo

While quite a few things have remained roughly identical, a great many things have changed as well of course. But for a very simple/minimalist overview of "how does an OS work at the most fundamental level" it's not a bad thing to look at. The code is either in Assembly or pre-ANSI C though, and is also not always the most clear code. Brevity indeed was a value.

Perhaps there are other very small examples which are better, maybe very early Linux releases would also be a good example. The old Unix stuff also has some historical value of course, which is the entire reason I looked at it in the first place.

*Edit*: I see now you're the same person who asked about learning C a few weeks ago, good to hear that's going well for you. However, since you seem to be somewhat new-ish to programming in general I'm actually not entirely sure if the old Unix code would really be a good fit, because like I said it's not the easiest code to follow by modern standards. I think there are some other more modern (but still small) "hobby OS's" out there.

[Carpetsmoker]

Happened to come across this today: https://github.com/vvaltchev/tilck

[HopingStar]

It is seem a great idea to read old Unix code like 4.4BSD. Maybe I could know how a basic BSD would work. I am not sure if old code are good practices and helpful for me like you said. But I will try to modernize my C knowledge to avoid insecure, unsafe and buggy code. Whatever happen next, I think I should try to look every modern system and old system to see how their design have and what I can learn from them. Thanks.