08:34 Actually, MUL and DIV also affect EDX. The MUL instruction stores the higher half of the result in EDX, while DIV stores the remainder from division there. If one dosn't know about that, one can be very surprised that suddenly their EDX is getting clobbered with "random" numbers after division/multiplication.

@OmbreeTV

4 жыл бұрын

Omg thank you so much, i've been trying to understand a code for a couple of days and couldn't figure out why edx was being pushed and pop before and after a multiplication

@lyrapuff7502

3 жыл бұрын

*boops*

@mikicerise6250

3 жыл бұрын

OMG, thanks soo much. If not for your comment I would still be mystified at the bizarre results of my test code. xD "Multiplication never works... division only works sometimes... duuhhh..." xD

@mikicerise6250

3 жыл бұрын

Another thing I've discovered on the MacOSX x64 side of things (still using NASM) is if you divide 64 bit integers the quotient is apparently given by RAX:RDX, for reasons I still don't understand, so since both RAX and RDX are 64 bit integers, aside from giving you the wrong answer, if anything substantial is in RDX it's a ticket to overflow-land unless you initialize RDX at 0 first.

@Kokurorokuko

2 жыл бұрын

How is storing higher half of the result useful?

“Assembly language is basically just a human-readable form of machine code” As a complete beginner who has just looked at Assembly code for the first time, I am crying both tears of laughter and pain at this statement

@mansodev

3 жыл бұрын

@Kraio have you tried lua or python? Their more higher level and easy to learn.

@nickstill2666

3 жыл бұрын

I hope you didnt give up but you'll want to start somewhere besides x86 assembly. There are loads of languages that make more sense and are more natural to write for a beginner.

@kraio-sfu

3 жыл бұрын

nick still Which one would you suggest? I have recently started wanting to make my own computer on a breadboard, but I want to be able to actually make programs for it. Do you think the Motorola 68010 would be an okay pick?

@kraio-sfu

3 жыл бұрын

The Planebagel Oh I absolutely love Python, it’s my main programming language. I just find it funny because calling Assembly “human-readable” is a very generous statement

@nickstill2666

3 жыл бұрын

@@kraio-sfu hell ya! A big project but could be rewarding. My personal preference (arm chair opinion) would be to start with a 6502. The Assembly lang is straight forward and there is a community around ROM creation for the 6502 with python and you can even by a kit for breadboarding it

Excelent, straight to the point and no "suscribe bull".... Great presentation and introduction

@ivandres73

3 жыл бұрын

@reena mola because you reference processors registries (eax, ebx, etc) without brackets ([ ]). You use brackets when referencing memory address ([0x400008]).

@ivandres73

3 жыл бұрын

@reena mola "mov eax,[ebx]". imagine ebx=0x40000. So we are saying: "mov eax, [0x40000]". imagine memory at 0x40000 = 20. So we are saying: "move eax, 20". Note, syntax might change a bit of how to reference a registry depending on the tool (at&t, intel, oracle...). But that is not the case for the example above.

@ivandres73

3 жыл бұрын

@reena mola No, registries do not have addresses, they are just... "there". Memory has addresses, and the more memory you have (2GB, 4GB, 8GB, etc) the more "addresses" you have.

@ivandres73

3 жыл бұрын

​@reena mola no. you are talking about the "sections" that a registry has. Every 32bit x86 registry has 4 sections, and those are different from memory addresses. memory addresses refers to the RAM. registries do not have addresses. registries can store addresses. references to sections of a registry is with 'ax, al, ah', and other special words; not with brackets. any RAM address is refered with brackets[ ]. [eax+4] = go to the RAM, at the location of eax+4. eax+4 = add 4 to the value stored in eax. (not sure if this is even permitted)

@ivandres73

3 жыл бұрын

@reena mola Make good use of knowledge! 🤙🏽

Thanks for making this video series for free. I am really glad. It is a massive help to me. Plus you really simplify it which good for a beginner like me.

I just had hours over hours of Assembly lessons at University... 6 Videos and I finaly get how it works! Well done! Thanks a lot!

You are the only person that i could find online that can explain things extremely well! Thanks so much!

Hey Davy, what a masterpiece of a tutorial series, I wanted to have an idea of what Assembly programming looked like and better understand very low level programming, well man i wasn't expecting to find such a brillant tutorial in video ! Thanks, and if you want to carry on with more advance stuffs in assembly, please don't hold your breath !

@xrafter

3 жыл бұрын

Assembly is a processor language but in human format.

Didn't make sense to me the first time I watched it. After reading through parts of a book, following a tutorial on tutorialspoint, this made SO much more sense. Thank you my man.

@omarelric

4 жыл бұрын

Salvador Yniguez hey dude, what book was it?

@mrkewi1

4 жыл бұрын

@@omarelric The Art Of Assembly

@omarelric

4 жыл бұрын

Fazil Sultan hey, I somehow came across the same book anyways 😂

@omarelric

4 жыл бұрын

Samyakt Jain “the art of assembly”

@samyaktjain698

4 жыл бұрын

@@omarelric I am beginner , please help me , where I learn Reverse engineering ?

I gave my thumb’s up to every episode of this series.

Thank you so much man, this really helped me to get the basics of this thing. I may be able to pass my college exam now.

I love your enthusiasm at the end

Finally a good tutorial on x86

I'm so glad you've made these videos. I been using asmtutor which is good, but it goes down a lot easier when you've got a good video series to follow along to. Dope shit man, thank you

Thank you for this great tutorial. Covered a lot of information and produced a working executable. You are a great teacher!

Thank you. And no needless Videohive inspired introductions! Straight to the point.

Absolutely brilliant. Nothing, I mean nothing at all worked on my computer from this tutorial.

Short and easy-to-follow presentations. Good job.

Great video Davy, clear and easy to follow. Thanks for putting it together

I know this is 3 years old, but this is a very good series and should be continued :)

Outstanding video series, thank you so much, it really helped. You are a pioneer of knowledge

Nice video! Good pace, well structured and clearly explained, thank you!

Amazing video series Davy! It's incredibly helpful!

@10:37 Wow amazing descriptions on the code. Seeing it in such fashion helped me understand the translation between that and c code. I believe there will be great insight learned from your video's! Thank you friend

happy I've found your videos. from this video alone, I already understood more, then in my lecture to this topic. Thanks for uploading such a great video series and taking your time explaining it so good!

@043_fazlerabbi5

Жыл бұрын

He is best

@hjrgf

Жыл бұрын

​​​@@043_fazlerabbi5 yeah the video is formatted to make it easy to learn all of the assembly stuff I remembered much more stuff than other tutorials 10/10 tutorial

This video is not really an "intro" but fortunately it's exactly what I need.

@blackham7

4 жыл бұрын

Eurgh You're such a squidward

You reeeeaaaly hace to watch it more than once... Great video!

This video just saved my whole day. Thank you! Now on to the rest of the playlist...

Thanks for this great, very comprehensible, video. Organization of the video (introduction and then development of the body part of this training) really is very nice, 👌👍

I am programmer for quite some time, but your videos seem to be the right way for me to move into asssembly more! Cheers

@meno437

10 ай бұрын

Crack your own programs good way of learning

This video suddenly appeared on my playlist after watching virus testing videos, I am interested in remember the Assembly Language, thanks for this content!!!!!

This was really very intresting! I think learning assembly teaches you a lot about computers!

Very helpful I watched a few tutorials and this is the easiest one to understand thank you.

This is great, and very helpful. Thanks for making it.

Hurray! Now we're getting somewhere, assembly is a set of different languages. I'm definitely bookmarking this.

Thanks, finally someone with a good tutorial!

Thank you for the great video, very clear explanations.

very useful and informative video, amazing work

What a great video. Thank you for making this! Subscribed.

Very helpful video. You are the best! Very fun language. Wish me luck!

The information in this video is spot on

Oh man what a find! Knowledgeable and understandable.

Davy you are a wonderful teacher

Your explained this way better than my professor ever did

Really thanks man we really were need this courses for learninh you really amazing and great persone dont stop 🔥👍👍👍👍🔥🔥

Great video, no bullshit, and excellently explained!

Good job - ignore the haters - we all have to start somewhere which is why many are here.

Thanks a lot for such a great explanation. I have seen a lot of super videos but I'm not clever enough to understand them, but now eventually I start to understand =D . Again Thanks a lot.

This was suprisingly easy to understand

@fighterjelly

3 жыл бұрын

what do you smoke to understand this god language ?

Excellent video, thanks man ! 👍👏

Great contents, great communication!

Awesome content, thanks for sharing this!

Example code: github.com/code-tutorials/assembly-intro Slides: docs.google.com/presentation/d/19nVBqrXdsvRHhAXPDwQodSoux-b_PXF9dBe-bfZJS2M

@godwhomismike

6 жыл бұрын

I really hope you teach computer science courses at your local college(s).

@Xerion567

6 жыл бұрын

godwhomismike From what I understand, computer science is more about mathematics and high level abstraction stuff. Most of the courses I've seen teach with Java, though I did know of least one school which focused on embedded systems.

@godwhomismike

6 жыл бұрын

I've had plenty of CS instructors that were not that great with math, but could code extremely well.

Great video, easy to follow

I came here from michael reeves saying this is a easy language and my friend says its not, naturally im going to torture myself to spite my friend. This will be my first coding language, wish me luck

@undefinedchannel9916

3 жыл бұрын

cmon atleast learn a high-level language to get used to big brain code logic like loops and if statements and stuff like that

@tree9380

3 жыл бұрын

@@undefinedchannel9916 my suffering is and will be immeasureable till im done and move on to less suffering like c++

@tree9380

3 жыл бұрын

@steev i do hate myself imdeed

@wassuupman764

3 жыл бұрын

@@tree9380 start with python or JS dude... you will lose motivation

@dilet1114

3 жыл бұрын

only the most chad of chads will be able to do that...

Wow, you teach Go and x86, you're a god

Been trying to teach myself x86 for a while, definitely not the 'nicest' language but a great feeling when it works

@drozcan

6 жыл бұрын

reverse engineering feels like pro

@wooseliedestine9382

5 жыл бұрын

@@drozcan Yes indeed

@bradley1995

9 ай бұрын

I'm learning to create a simple "compiler" using java for a lex/parser and to generate asm code. I'm super excited!

I wish we had a professor for assembly & computer architecture like you in my Uni 😅

@MrGSA1310

3 жыл бұрын

I wish I had a professor who teach me something instead of forcing me to watch this kind of videos in order to have any hope of success for his exam 😢

@grandmakisses9973

3 жыл бұрын

@@MrGSA1310 that’s what I’m scared for I’m going to university soon :( wish me luck

I've seen assembly code that just uses syscall instead of int 0x80 and as far as I know it does exactly the same. Does it matter what I use? My best guess is that syscall might be something specific to nasm and int 0x80 is more common across assemblers.

To the point. Excellent video.

Good video. Thnx sir. Kindly upload more video on assembly language

very clear and efficient thank u

Great explanation!

Great video man!!!!!!!!

OMGG thank uuu Davy 😍😍😍😍😍

thanks bro. amazing video

Awesome video, thanks!

One thing you should mention is that there are two ways to write x86-64 assembly. The one you've shown in your video is the Intel syntax which is a lot nicer and readable, but is read right-to-left. The other one, which is just as common, is the AT&T and GNU syntax which is more complex and is read left-to-right.

Great video!!

Great stuff!!

Bro u just explained this easy

Nice and simple. Thank you!

I'd love to see the final right half of the video, but it's populated by overlays. I've got annotations turned off, but they still show up.

First part was informative but. You left out what the different keywords means once you get to 10:08. msg db "Hello World!",10,0 //Here we append ' '(newline) and the numeral 0 to our string in order to 0 terminate it(0-terminated string) - which is good practice. Also you didn't create a string of bytes but an array of bytes. You defined bytes(db). So you defined an array containing characters "Hello world! ". Which you could also have done like so although very messy: msg db 'H', 'e' , 'l',' l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', '!', 0x0a len equ $ - msg // equ is used to define contants. "$" evaluates to the assembly position at the beginning of the line containing the expression(current address). Also maybe tell us why it works. It is not obvious for everyone that you're taking the address exactly after making your string and subtracting the address of the very start of the string. Please remember to tell us what each keyword does and means.

@DavyBot

6 жыл бұрын

You don't need to end your string with a 0x00 unless you're dealing with C library functions. The system call for writing to stdout requires the length and that 0x00 doesn't matter. Also... What do you think the difference between a string and an array of character bytes is? :) Also, to each their own. I write the bytes out in hex format as 0x0a instead of just 10 or even 0xa because I'm used to working with hex editors (as people working with low level languages like this tend to be). But, yes, I could have explained in more detail that the $ was for taking the location after the string.

@g4yktzgjx6

6 жыл бұрын

There is no difference between a string and an array of characters. But in the video you called it a string of bytes. Which I find wrong. It is an array of bytes or a sequence of bytes representing a string.

@DavyBot

6 жыл бұрын

They're all valid terms. You probably hear people use "string of bytes" more when they've had to deal with unicode strings in addition to ascii strings. But you're just being picky (or not being picky enough?), it isn't "wrong". en.wikipedia.org/wiki/String_(computer_science)#Representations www.google.com/search?tbm=bks&q=%22string+of+bytes%22

@homelessrobot

3 жыл бұрын

A more relevant section of that wikipedia article is probably: en.wikipedia.org/wiki/String_(computer_science)#Non-text_strings (maybe it wasn't there two years ago) The meaning of the word 'string' has evolved to mean 'a sequence of character elements' (or whatever) over time, but its really just another word for vector, array, or sequence. In particular if you are working on x86 in machine instructions, you should probably already be somewhat familiar with this because there are a whole class of string operations for x86 that aren't related t zero terminated character encoding anything. They are just for operating over a contiguous, addressable sequences of elements of a given size.

Thanks for the knowledge!

That was pretty cool.

You are a god, sir. Thank you!

10:32 I am a little bit confused. How does the System know, if we want to store the value 4 into the eax to calculate with it or if we want a system call? I don't get it?

You've saved my college semester, sir. Thank you.

when I first got it to compile, I was so happy haha

good teacher thanks from Peru

Very cool series. I wish my professors taught like you. Any plans on doing a series on ARM64 or x86_64 assembly?

@ShivanshPlays1

2 жыл бұрын

I think this series is about x86_64

Thanks for the tutorial🥰🥰🥰

Great video.

Awesome video

5:44 *accumulator register, the first important one. Something that is missing is the general purpose registers' description/declaration/definition.

Nice. Many years ago i write some Asm code in dos. And use int 13h mode to create games.

Great video :)

I really enjoyed this. I'm currently reading the PDF Reverse Engineering For Beginners (understanding Assembly Language) and it gets a bit heavy at times when it talks about different CPU architecture sets and different compiler output. But your video is straight to the point. Thanks

I’m about to watch this 😁

@eddiemorales4728

4 жыл бұрын

Have you watched it yet?

@lilraahdreadlockvideosandm1648

4 жыл бұрын

Eddie Morales yea I watched all 6 videos

@lilraahdreadlockvideosandm1648

4 жыл бұрын

Eddie Morales your about to watch ?

@eddiemorales4728

4 жыл бұрын

@@lilraahdreadlockvideosandm1648 nice.. I watched the first and bookmarked and subscribed for later.. I got worried.. you told us you were going to watch a month ago and disappeared 😆

If using visual studio (2019) is any of the syntax different from these examples? I'm getting syntax errors when attempting to run the code. I just briefly checked a different video specifically for setting up visual studio for assembly and their example ran fine.

so how are these system calls in memory? is this the bios or like the linux kernel? are these system calls just C function pointers?

Thanks for this :)

I hadn't been this excited to print "hello world" before.

man i wanna thank you

Very clear

Do you cover the topic of self-modifying code?

You know, I'm glad I know other languages as well. I might find a way to automate some of this.

Finally, some good fking -food- _tutorial_

Ciao, secondo te è possibile imparare a programmare (intendo a scopo didattico) in assembler senza la conoscenza dell'architettura del calcolatore ? Oppure in alternativa cosa è necessario saper conoscere e mi riferisco all'architettura per poter affrontare la programmazione in assembler ?

is there any way to use the assembly code in online websites? Codechef or codeforces?