#1 How to Build a Virtual Machine from Scratch

In this series we'll learn how to build a virtual machine in c++ from scratch. This series is designed to provide insight into how computers work, and therefore is an attempt to be as simple as possible.
source code: github.com/pbohun/stack-vm-tu...

[@MrTarakrigia]

Awesome video. Unique stuff!!! Atleast I got the glimpse of how a VM works under the hood. Thanks man!

[@joshuaorthodox]

Yes! I have been craving to do this myself, but I had no idea where to get started, thank you so much!!

[@andycouto7688]

This is one of the best videos on how to build a VM I have found thank you for posting this!

[@philipbohun740]

Thank you!

[@AveChristusRex]

Nice vid! Woking on something similar at the moment.

[@256k_]

i have been looking for a video like this! thank you!

[@jordilagaresroset8396]

after watching this, the least i can do is subscribing ;P
*EDIT*: Wow thank for the heart!

[@suckinDiesel44]

Great video, no nonsense straight into things. Subscribed!

[@SaifUlIslam-db1nu]

Hi!
Where and how did you read about this material? Where did you get this knowledge from?
Thanks!

[@memoriasIT]

Good job man! Interested in this, let's see when I manage to do this :P

[@volcanobeard8668]

3 years later: how it went?

[@patricktorgerson5810]

This is awesome. and surprisingly simple

[@philipbohun740]

Thanks!

[@sirpeanutgaming2749]

What resources did you use to help gather information on this subject?

[@needlessoptions]

Parred lmao

[@willbou2011]

That was just awesome!

[@philipbohun740]

Thank you!

[@betaalpha3062]

Amazing! I like this !!!

[@notsoverflow]

thank you, really awesome tutorial :D

[@philipbohun740]

Thanks!

[@dragonfly3139]

awesome thank you for putting this up

[@philipbohun740]

You're welcome!

[@dmitryponyatov2158]

can you recommend some video or tutorials about writing Python-like object virtual machine?

[@miquel6572]

Does anybody know some book or article where i can learn more abou the theoretical background to this?

[@pruthvim.g9057]

I'm getting segmentation fault(core dumped).....while compiling....solution?

[@easynavigation847]

Please which type of hypervisor would we say this machine use.

[@ahmadabushawar5101]

Im getting 0 at the top of the stack and i cant figure out the reason why.

[@tutacat]

That's not how negative works, the first bit just is an easy way to see if it is negative. negative is inverted bits !(x) then -1 (since you start counting at -128 for example in 8 bit byte
So 7: 0111 -> 1001

[@bunmimichael-asalu2069]

Hello, Quick Question, Do you know how to do this on mac? Is there an app i can install to do this? Thanks

[@philipbohun740]

You can check to see if you already have gcc installed by opening Terminal and typing: which gcc
If nothing shows then you'll probably want the homebrew package manager: brew.sh/
Then you can install gcc like so: brew install gcc
That will give you the c compiler and then you can use whatever text editor you want.

[@AlphaEtOmega43]

Why you didn't use a std::stack rather than a std::vector for your stack ^^ ?

[@philipbohun740]

std::stack would've been better for this simple example. Though I think if one was serious about performance std::vector is probably the better choice, since it guarantees contiguous allocation of memory which encourages speed. I think in future tutorials I will try to consider simplicity over speed.

[@NIKHIL-yl1ws]

Which OS are you using in this video??

[@rtzgf67games7]

Ubuntu Linux

[@meegz149]

I use the exact same code but visual studio is telling me that the vector subscript is out of range. Anyone know why that is?

[@philipbohun740]

If you run the program in debug mode you can use break statements around where you access any vectors that you have and see what the values are.
Otherwise you can use print statements printing out the index before you access any elements of a vector. That should help narrow down the exact line where something is going wrong.
Good luck!

[@seanmccain1450]

Likely because your program counter (pc) doesn’t start at 100.

[@seanmccain1450]

But that just means you are trying to get something that isn’t in the vector.

[@lincolnsand5127]

@@philipbohun740 it's because you used reserve instead of resize

[@zerol3971]

Can I get the download site to the new Microsoft terminal?

[@hexagonist23]

Why would you want that?

[@rtzgf67games7]

@aperturechromakey72 There's a high chance the person asking for "the new windows terminal" thinks that the terminal they see in the video is in fact windows terminal.

[@dariusfitzpatrick5129]

what kind of script is that

[@VS-lq4rj]

Can I set the GPU cpu and ram of my choice

[@rtzgf67games7]

If you implement it lmao

[@r50142]

Im using this for opencomputers.

[@jeanrodrigues6249]

o garoto e bom

[@marete100]

aren`t typedefs C style C++?

[@philipbohun740]

Typedefs are a part of the C language. Modern C++ has both more ways and fancier ways to do typedef-like things.

[@lincolnsand5127]

Yeah. C++ now uses `using` instead. It fixes some edge cases with certain types (mostly templates)

[@ziad_vfx]

Is it c++ or c?
Plz answer

[@TheOriginalDuckley]

Read the description.
Also C doesn’t have classes. C++ does.

[@lincolnsand5127]

Fyi, you misused vector and invoked UB. You want to use `resize` or the constructor, not `reserve`

[@SR-er6hx]

No. Reserve is best here since it allocate memory ahead.

[@lincolnsand5127]

@@SR-er6hx You can't index after doing reserve. Reserve is not guaranteed and often doesn't allocate extra memory. They meant to type resize.

[@GarrettKingdom]

*that moment when he starts typing and you realize this is c++ and not c#*

[@GarrettKingdom]

Also, I wrote that comment from inside a VM :3

[@pendergastj]

who gives a fuck

[@KaiDuquet]

Well I'm glad he is not using C# for a VM, for many reasons. For one, just... no

[@haykg]

Jamie Pendergast lmao

[@volcanobeard8668]

But c sharp :(

[@ProTest-ow1vs]

اصبر يا عسل

[@jeanrodrigues6249]

apt

[@aritrajana3211]

64 bit

[@somewhatBoring]

python