11 ms·

How to Make a Computer Operating System in C/C++

235 points by SamyPesse 13y ago

vezzy-fnord 13y ago
Obviously this is still in its very early stages, but I can see this becoming a very informative and practical course. I'll definitely be keeping an eye on this. Do you intend on turning this into a book and perhaps publishing physical copies?
- SamyPesse 13y ago
  Yes it's very early stages I'm looking for feedback on how to structure the course. No I don't think so, I just want to an informative resource from what I've learned.
  - sown 13y ago
    Thank you for building this. As weird as it sounds saying this out loud, you've made the world slightly better.
  - SyneRyder 13y ago
    In case you haven't heard of it, you might want to take a look at LeanPub, who specialize in books that are published while they are being written, have a particular focus on Software Development books, and accept manuscripts written in Markdown stored in a Dropbox folder. You can then take the finished LeanPub book to a print-on-demand company like Lulu or CreateSpace to created printed books as well: https://leanpub.com/authors I actually assumed you were making a LeanPub book, and was considering buying the work in progress.
tejasm 13y ago
Very interesting. A friend and I tried creating our own OS back in 2002 using interrupts to write the boot program. I wish I had this tutorial back then.
Spl3en 13y ago
Another very complete tutorial : http://www.brokenthorn.com/Resources/OSDevIndex.html http://www.brokenthorn.com/Resources/OSDevIndex.html
winocm 13y ago
I just wish more people dealt with ARM instead of x86. It's a far better architecture for people to learn system design.
- slunk 13y ago
  I've been looking for good OS dev tutorials for ARM. Does anyone know of any besides Baking Pi?
  - girvo 13y ago
    My research about 12months ago didn't give much, sadly.
- maaaats 13y ago
  Why? (I'm curious as I know little of these kinds of things, and because citing sources or giving arguments is always a good thing)
  - winocm 13y ago
    For example, look at all of the legacy stuff in an x86 system. You have the strange structure of the interrupt descriptor table/global descriptor table. You have the good old Intel 8042 keyboard controller, Intel 8259 programmable interrupt controller, old-style programmable interval timer, A20 gate and so much more. There's so much legacy baggage inherent in the x86 architecture, all because of software compatibility. (ROM-BASIC will still run on a modern PC!) ARM on the other hand has less to really worry about, sure there's some legacy infrastructure, such as the ARM vector table. Modern ARM architectures such as ARMv8-A remove old legacy baggage in favor of completely renovating it. (Look at the old coprocessor interface for instance. In A64 mode, it is completely gone. You must use 'mrs/msr' instructions compared to 'mrc/mcr'). There's also far less legacy software to worry about.
slunk 13y ago
Fyi, at least at first, this looks like it will be very similar to a few wonderful tutorials and projects I have been going through lately: * http://www.jamesmolloy.co.uk/tutorial_html/index.html http://www.jamesmolloy.co.uk/tutorial_html/index.html * http://www.osdever.net/tutorials/view/brans-kernel-development-tutorial http://www.osdever.net/tutorials/view/brans-kernel-developme... * https://github.com/klange/toaruos https://github.com/klange/toaruos ...and just in case anyone is curious, my own project (about half way through James M's tutorial - working on virtual memory management): https://github.com/slunk/Hobbyos https://github.com/slunk/Hobbyos Oh, and btw, this looks AWESOME. I am looking through the finished chapters right now!
deleted 13y ago
[deleted]
clarry 13y ago
It's not C/C++. C/C++ is not a language. The project's goal is to write a very simple UNIX-based operating system in C++ (does anyone else smell a contradiction?). The code is predominantly C++.
- Houshalter 13y ago
  I thought it was a reference to this* when I read the title, but after reading them both I'm not sure there is any connection. *http://i.imgur.com/fQ1ST8w.jpg http://i.imgur.com/fQ1ST8w.jpg
  - 10098 13y ago
    please tell me it was some kind of joke
    - Houshalter 13y ago
      Possibly but I think it's real. I believe it's the same guy from this: http://i.imgur.com/evPQL2S.jpg http://i.imgur.com/evPQL2S.jpg
      - 10098 13y ago
        Found that guy's facebook. It does seem real, I mean the person seems real, but I still really hope they're doing this as a joke or something.
- smnrchrds 13y ago
  You are correct. Usually I see this in CVs. It usually means that the person is proficient in C++ but knows a little C as well. But C/C++ can be a language. It could be a code written in C++ but looks more like C than C++. Some people e.g. use character arrays instead of string class, avoid STL as much as possible, don't use object-oriented aspects of the language, etc. The end result uses some C++ libraries, compiles on a C++ compiler but resembles C more than anything. I think it would be appropriate to call it C/C++.
zplesivcak 13y ago
Here [1] you can find another example of writing OS from scratch. Going through chapters progress is made iteratively by making limited changes in each step. This OS is intended to be (RT)OS for embedded computers, but example arch-level is implemented for x86. [1] https://github.com/l30nard0/Benu https://github.com/l30nard0/Benu
Jagat 13y ago
I am a graduate student, currently working on building a x86_64 unix like preemptive kernel from scratch, as part of a course. Most of the OS dev guides and books focus on 32 bit arch and I haven't found a single guide so far that is based on 64 bit arch. Since this this guide seems to be in its inception, I hope someone (hopefully me) will send a pull request for a 64 bit tutorial. Building an OS has been in my bucket list for long and it has been one heck of an experience so far. Here are some good step-by-step OS-from-scratch programming guides http://jamesmolloy.co.uk/tutorial_html/index.html http://jamesmolloy.co.uk/tutorial_html/index.html http://www.osdever.net/bkerndev/Docs/title.htm http://www.osdever.net/bkerndev/Docs/title.htm http://www.ijack.org.uk/ http://www.ijack.org.uk/ http://www.brokenthorn.com/Resources/OSDevIndex.html http://www.brokenthorn.com/Resources/OSDevIndex.html http://viralpatel.net/taj/operating-system-tutorial.php http://viralpatel.net/taj/operating-system-tutorial.php and here's a good wiki for reference http://wiki.osdev.org/Expanded_Main_Page http://wiki.osdev.org/Expanded_Main_Page
- mvanotti 13y ago
  I think that AMD Developer Guides & Manuals [1] are very good resources for x86_64 System Programming (better than Intel Manuals). They are better explained and focus on x86_64 arch. [1]: http://developer.amd.com/resources/documentation-articles/developer-guides-manuals/ http://developer.amd.com/resources/documentation-articles/de...
  - dkersten 13y ago
    I still have a soft spot for the intel manuals.. probably because I managed to get print copies right before they stopped giving them out :)
- csmuk 13y ago
  Building OS' is fun. I wish I could spend all day doing it but I've been pushed so far up the stack that I spend most of the time arguing with analysts and preparing documentation... I've built two so far which were (and I think still were until recently) used in production equipment. One Forth system (all 8k of it) that ran a PLC system and a tiny (16k) kernel for an M68k system that was a router for a modbus-like protocol over RS485. Nothing x86_64 but nevertheless the most fun I've ever had with a computer.
devhinton 13y ago
This is great. I am just jumping into open source from an academic background. I had assumed that open source was great for directly practical website creating and hosting (back-end, client side etc...) but weaker in terms of learning for OS / compilers. This post and its comments (with linked resources) are making me unsure about this assumption. What do you think?
djvu9 13y ago
For those who are interested in developing a realistically useful small OS in C++ (or even C++ 11), you may probably want to check out OSv https://github.com/cloudius-systems/osv/ https://github.com/cloudius-systems/osv/ developed by previous KVM guys.
waterside81 13y ago
Who remembers Nachos? https://en.wikipedia.org/wiki/Not_Another_Completely_Heuristic_Operating_System https://en.wikipedia.org/wiki/Not_Another_Completely_Heurist... 3rd year OS class we had to use Nachos as our base OS and build your usual file management, pipes etc. functionality on top of it. Really taught you how an OS works.
- austinz 13y ago
  Our school used Pintos, a derivative of Nachos. Taking the OS course there was an eye-opener for a student as technically immature and inexperienced as I was at that time, but it was also a tremendous learning experience. I've always wished I could go back and retake that course, the 'right way'...with these resources, though, maybe there's a better way.
rst 13y ago
Might also be worth looking at xv6, which is a rewrite of Unix v6 in modern C, and comes with an exegesis modelled on the classic Lions book: http://pdos.csail.mit.edu/6.828/2012/xv6.html http://pdos.csail.mit.edu/6.828/2012/xv6.html (Although if you want to run the original Unix v6, written in a now-archaic proto-C --- unsigned integer variables are declared as pointers because "unsigned" itself wasn't directly supported in the language yet --- PDP-11 emulators and system images are readily available.)
e12e 13y ago
Maybe a little irationally, the idea of programming an os in c++ strikes me as very opaque. I think the vipri[1] approach of layering dsls, or the smalltalk idea of a relatively simple vm to seem more understandable than an os that embeds a c++ runtime... As a side note, when looking up [1] I also ran across [2]. [1] http://piumarta.com/software/cola/ http://piumarta.com/software/cola/ [2] http://www.acm.uiuc.edu/sigops/roll_your_own/1.helloworld.html http://www.acm.uiuc.edu/sigops/roll_your_own/1.helloworld.ht...
- dnautics 13y ago
  BeOS was primarily written in C++, although the kernel was dominantly C. For actual parts that require user interaction, C++ and the object model makes a whole lot of sense, although there are probably more mature languages out that would be better candidates now.
  - crusso 13y ago
    I loved BeOS and the C++ application framework... except for the linking model. You had to provide re-linked executables for every new version of BeOS that came out. It was exceedingly lame to go to an application download page and have to select the version of the application that corresponded to the version of BeOS you installed. Then when you upgraded your OS, you had to upgrade ALL of your applications. Sure, there were some framework upgrades that didn't necessitate a re-linked application, but as a user you never really knew which those were so had to do a full upgrade of everything to be sure.
    - dnautics 13y ago
      Agreed. Although, I don't understand why they didn't provide "shim" .so files. I think this is what linux does, though in practice these days I just use ubuntu packages... And at the time to do the same thing in linux, or FreeBSD (which is what I migrated to when I left BeOS) you had to - or were encouraged to - recompile everything from source.
  - 10098 13y ago
stonewhite 13y ago
"It was written several years ago as one of my first projects when I was in High School" High school? Really? Are there any proper highschools like these? I am jealous now.
exDM69 13y ago
A hobby operating system project - everyone's gotta have one, right? There are many like it but this one is mine: https://github.com/rikusalminen/danjeros https://github.com/rikusalminen/danjeros It's an x86_64 bare bones kernel project, doesn't do much except for boot and handle some interrupts. There's a little multitasking and some related stuff. Unfortunately there's only a finite amount of time in the world, and not too much of it is available for me to dedicate to this project.
xradionut 13y ago
How about making a language, compiler, OS and applications and not use C or C++ ? https://news.ycombinator.com/item?id=6829464 https://news.ycombinator.com/item?id=6829464
- reirob 13y ago
  You forgot to add in your list: making a completely new processor ;) Which the linked project actually achieves.
  - xradionut 13y ago
    There's that too. Although I'd like to have the time to port Oberon to MIPS, maybe the PIC32 since the more powerful, modern MIPS chips are out of budget. Haven't done the analysis, but I think it would be a good match.
agumonkey 13y ago
Been reading Massalin's Thesis on Synthesis OS (partially evaluated, dynamically generated kernel code), it's a refreshing and very inspiring read: http://valerieaurora.org/synthesis/SynthesisOS/ http://valerieaurora.org/synthesis/SynthesisOS/

235 points by SamyPesse 13y ago

Obviously this is still in its very early stages, but I can see this becoming a very informative and practical course. I'll definitely be keeping an eye on this. Do you intend on turning this into a book and perhaps publishing physical copies?

SamyPesse 13y ago
Yes it's very early stages I'm looking for feedback on how to structure the course. No I don't think so, I just want to an informative resource from what I've learned.
- sown 13y ago
  Thank you for building this. As weird as it sounds saying this out loud, you've made the world slightly better.
- SyneRyder 13y ago
  In case you haven't heard of it, you might want to take a look at LeanPub, who specialize in books that are published while they are being written, have a particular focus on Software Development books, and accept manuscripts written in Markdown stored in a Dropbox folder. You can then take the finished LeanPub book to a print-on-demand company like Lulu or CreateSpace to created printed books as well: https://leanpub.com/authors I actually assumed you were making a LeanPub book, and was considering buying the work in progress.

tejasm 13y ago

Very interesting. A friend and I tried creating our own OS back in 2002 using interrupts to write the boot program. I wish I had this tutorial back then.

Spl3en 13y ago

Another very complete tutorial : http://www.brokenthorn.com/Resources/OSDevIndex.html http://www.brokenthorn.com/Resources/OSDevIndex.html

winocm 13y ago

I just wish more people dealt with ARM instead of x86. It's a far better architecture for people to learn system design.

slunk 13y ago
I've been looking for good OS dev tutorials for ARM. Does anyone know of any besides Baking Pi?
- girvo 13y ago
  My research about 12months ago didn't give much, sadly.
maaaats 13y ago
Why? (I'm curious as I know little of these kinds of things, and because citing sources or giving arguments is always a good thing)
- winocm 13y ago
  For example, look at all of the legacy stuff in an x86 system. You have the strange structure of the interrupt descriptor table/global descriptor table. You have the good old Intel 8042 keyboard controller, Intel 8259 programmable interrupt controller, old-style programmable interval timer, A20 gate and so much more. There's so much legacy baggage inherent in the x86 architecture, all because of software compatibility. (ROM-BASIC will still run on a modern PC!) ARM on the other hand has less to really worry about, sure there's some legacy infrastructure, such as the ARM vector table. Modern ARM architectures such as ARMv8-A remove old legacy baggage in favor of completely renovating it. (Look at the old coprocessor interface for instance. In A64 mode, it is completely gone. You must use 'mrs/msr' instructions compared to 'mrc/mcr'). There's also far less legacy software to worry about.

slunk 13y ago

Fyi, at least at first, this looks like it will be very similar to a few wonderful tutorials and projects I have been going through lately: * http://www.jamesmolloy.co.uk/tutorial_html/index.html http://www.jamesmolloy.co.uk/tutorial_html/index.html * http://www.osdever.net/tutorials/view/brans-kernel-development-tutorial http://www.osdever.net/tutorials/view/brans-kernel-developme... * https://github.com/klange/toaruos https://github.com/klange/toaruos ...and just in case anyone is curious, my own project (about half way through James M's tutorial - working on virtual memory management): https://github.com/slunk/Hobbyos https://github.com/slunk/Hobbyos Oh, and btw, this looks AWESOME. I am looking through the finished chapters right now!

deleted 13y ago

[deleted]

clarry 13y ago

It's not C/C++. C/C++ is not a language. The project's goal is to write a very simple UNIX-based operating system in C++ (does anyone else smell a contradiction?). The code is predominantly C++.

Houshalter 13y ago
I thought it was a reference to this* when I read the title, but after reading them both I'm not sure there is any connection. *http://i.imgur.com/fQ1ST8w.jpg http://i.imgur.com/fQ1ST8w.jpg
- 10098 13y ago
  please tell me it was some kind of joke
  - Houshalter 13y ago
    Possibly but I think it's real. I believe it's the same guy from this: http://i.imgur.com/evPQL2S.jpg http://i.imgur.com/evPQL2S.jpg
    - 10098 13y ago
      Found that guy's facebook. It does seem real, I mean the person seems real, but I still really hope they're doing this as a joke or something.
smnrchrds 13y ago
You are correct. Usually I see this in CVs. It usually means that the person is proficient in C++ but knows a little C as well. But C/C++ can be a language. It could be a code written in C++ but looks more like C than C++. Some people e.g. use character arrays instead of string class, avoid STL as much as possible, don't use object-oriented aspects of the language, etc. The end result uses some C++ libraries, compiles on a C++ compiler but resembles C more than anything. I think it would be appropriate to call it C/C++.

zplesivcak 13y ago

Here [1] you can find another example of writing OS from scratch. Going through chapters progress is made iteratively by making limited changes in each step. This OS is intended to be (RT)OS for embedded computers, but example arch-level is implemented for x86. [1] https://github.com/l30nard0/Benu https://github.com/l30nard0/Benu

Jagat 13y ago

I am a graduate student, currently working on building a x86_64 unix like preemptive kernel from scratch, as part of a course. Most of the OS dev guides and books focus on 32 bit arch and I haven't found a single guide so far that is based on 64 bit arch. Since this this guide seems to be in its inception, I hope someone (hopefully me) will send a pull request for a 64 bit tutorial. Building an OS has been in my bucket list for long and it has been one heck of an experience so far. Here are some good step-by-step OS-from-scratch programming guides http://jamesmolloy.co.uk/tutorial_html/index.html http://jamesmolloy.co.uk/tutorial_html/index.html http://www.osdever.net/bkerndev/Docs/title.htm http://www.osdever.net/bkerndev/Docs/title.htm http://www.ijack.org.uk/ http://www.ijack.org.uk/ http://www.brokenthorn.com/Resources/OSDevIndex.html http://www.brokenthorn.com/Resources/OSDevIndex.html http://viralpatel.net/taj/operating-system-tutorial.php http://viralpatel.net/taj/operating-system-tutorial.php and here's a good wiki for reference http://wiki.osdev.org/Expanded_Main_Page http://wiki.osdev.org/Expanded_Main_Page

mvanotti 13y ago
I think that AMD Developer Guides & Manuals [1] are very good resources for x86_64 System Programming (better than Intel Manuals). They are better explained and focus on x86_64 arch. [1]: http://developer.amd.com/resources/documentation-articles/developer-guides-manuals/ http://developer.amd.com/resources/documentation-articles/de...
- dkersten 13y ago
  I still have a soft spot for the intel manuals.. probably because I managed to get print copies right before they stopped giving them out :)
csmuk 13y ago
Building OS' is fun. I wish I could spend all day doing it but I've been pushed so far up the stack that I spend most of the time arguing with analysts and preparing documentation... I've built two so far which were (and I think still were until recently) used in production equipment. One Forth system (all 8k of it) that ran a PLC system and a tiny (16k) kernel for an M68k system that was a router for a modbus-like protocol over RS485. Nothing x86_64 but nevertheless the most fun I've ever had with a computer.

devhinton 13y ago

This is great. I am just jumping into open source from an academic background. I had assumed that open source was great for directly practical website creating and hosting (back-end, client side etc...) but weaker in terms of learning for OS / compilers. This post and its comments (with linked resources) are making me unsure about this assumption. What do you think?

djvu9 13y ago

For those who are interested in developing a realistically useful small OS in C++ (or even C++ 11), you may probably want to check out OSv https://github.com/cloudius-systems/osv/ https://github.com/cloudius-systems/osv/ developed by previous KVM guys.

waterside81 13y ago

Who remembers Nachos? https://en.wikipedia.org/wiki/Not_Another_Completely_Heuristic_Operating_System https://en.wikipedia.org/wiki/Not_Another_Completely_Heurist... 3rd year OS class we had to use Nachos as our base OS and build your usual file management, pipes etc. functionality on top of it. Really taught you how an OS works.

austinz 13y ago
Our school used Pintos, a derivative of Nachos. Taking the OS course there was an eye-opener for a student as technically immature and inexperienced as I was at that time, but it was also a tremendous learning experience. I've always wished I could go back and retake that course, the 'right way'...with these resources, though, maybe there's a better way.

rst 13y ago

Might also be worth looking at xv6, which is a rewrite of Unix v6 in modern C, and comes with an exegesis modelled on the classic Lions book: http://pdos.csail.mit.edu/6.828/2012/xv6.html http://pdos.csail.mit.edu/6.828/2012/xv6.html (Although if you want to run the original Unix v6, written in a now-archaic proto-C --- unsigned integer variables are declared as pointers because "unsigned" itself wasn't directly supported in the language yet --- PDP-11 emulators and system images are readily available.)

e12e 13y ago

Maybe a little irationally, the idea of programming an os in c++ strikes me as very opaque. I think the vipri[1] approach of layering dsls, or the smalltalk idea of a relatively simple vm to seem more understandable than an os that embeds a c++ runtime... As a side note, when looking up [1] I also ran across [2]. [1] http://piumarta.com/software/cola/ http://piumarta.com/software/cola/ [2] http://www.acm.uiuc.edu/sigops/roll_your_own/1.helloworld.html http://www.acm.uiuc.edu/sigops/roll_your_own/1.helloworld.ht...

dnautics 13y ago
BeOS was primarily written in C++, although the kernel was dominantly C. For actual parts that require user interaction, C++ and the object model makes a whole lot of sense, although there are probably more mature languages out that would be better candidates now.
- crusso 13y ago
  I loved BeOS and the C++ application framework... except for the linking model. You had to provide re-linked executables for every new version of BeOS that came out. It was exceedingly lame to go to an application download page and have to select the version of the application that corresponded to the version of BeOS you installed. Then when you upgraded your OS, you had to upgrade ALL of your applications. Sure, there were some framework upgrades that didn't necessitate a re-linked application, but as a user you never really knew which those were so had to do a full upgrade of everything to be sure.
  - dnautics 13y ago
    Agreed. Although, I don't understand why they didn't provide "shim" .so files. I think this is what linux does, though in practice these days I just use ubuntu packages... And at the time to do the same thing in linux, or FreeBSD (which is what I migrated to when I left BeOS) you had to - or were encouraged to - recompile everything from source.
- 10098 13y ago

stonewhite 13y ago

"It was written several years ago as one of my first projects when I was in High School" High school? Really? Are there any proper highschools like these? I am jealous now.

exDM69 13y ago

A hobby operating system project - everyone's gotta have one, right? There are many like it but this one is mine: https://github.com/rikusalminen/danjeros https://github.com/rikusalminen/danjeros It's an x86_64 bare bones kernel project, doesn't do much except for boot and handle some interrupts. There's a little multitasking and some related stuff. Unfortunately there's only a finite amount of time in the world, and not too much of it is available for me to dedicate to this project.

xradionut 13y ago

How about making a language, compiler, OS and applications and not use C or C++ ? https://news.ycombinator.com/item?id=6829464 https://news.ycombinator.com/item?id=6829464

reirob 13y ago
You forgot to add in your list: making a completely new processor ;) Which the linked project actually achieves.
- xradionut 13y ago
  There's that too. Although I'd like to have the time to port Oberon to MIPS, maybe the PIC32 since the more powerful, modern MIPS chips are out of budget. Haven't done the analysis, but I think it would be a good match.

agumonkey 13y ago

Been reading Massalin's Thesis on Synthesis OS (partially evaluated, dynamically generated kernel code), it's a refreshing and very inspiring read: http://valerieaurora.org/synthesis/SynthesisOS/ http://valerieaurora.org/synthesis/SynthesisOS/