Programming & Debugging: C to Assembly

[LilMJflex]

you speak french? Parlez-vous Francias?



[cssaheel]

thanks brother

[darkdan4ever]

ollydebug FTW!! =)

[71GA]

GCC -S option... soooo usefulll.... can make faster programs using this :)

[happygamestvfun1]

lol

"we don't need this code, i dont' nkwo what it does" infact ill remove it, *dellete*" "now computer "compile(he measn assemble)!" *pc crashes" "oh... god....shit...."

[happygamestvfun1]

egh i hate ur voice

[Muhafaka]

u got sexy accent :)

[Gr8gabe]

Does this mean that most programming languages usually translate to Assembly, or is this just for C?

[SNaRF66666666]

@Gr8gabe all translate to machine code.

[thealeksass]

Can you say why there is some unnecessary code in compiled C program?

[eskizonet]

"gcc -S -masm=intel file.c"

This generates a Intel syntaxe file. =)

[ralienpp]

This is a good intro, I think it is worth dedicating some time to explain the difference between the Intel syntax and the other one.

I have made some superficial experiments with assembly code and for now I only know that Intel syntax is easier to read, but perhaps the other notation has some benefits?

[VladimirVichfret]

nice

[Entertainmentwf]

Awesome thank you for this video :). I just started learning about assembly language in my computer systems course. This would help me understand it a bit.

[Ronnieflip]

Thanx dude, this helped me alot

[DarkInjection]

how to change the assembly code in one memory adress using C??

lets say i got the adress 0x5412

and i wanna use nop(0x90)

im trying it with writeprocessmemory() but the program crash any solution??

[youhakim]

Hi,

You don't use any special function for that, you just open the executable file in binary, read, write mode using the fopen function and ... look for what you need to replace and replace it.

file_pointer = fopen("file.exe", "r+ b");

r+ : to open an existant file in read and write mode.

b : to open a file in binary mode.

[DarkInjection]

well can u give me an example?

i have try it with fopen,strstr and fputs but i cant make it work

[youhakim]

Ok, I've decided to make a video to demonstrate that, so stay tuned!

[DarkInjection]

wow :) thnx

[youhakim]

Oops! I didn't answer your question, did I?

I didn't ignore your real question, I just assumed without reading carefully that you were talking about how to patch a program, but you were talking about how to program a "Trainer" which "changes parts of memory used by a game to for example gain more money, [weapons,] etc", I don't know where was my mind? I'll try to answer you in a future video, and if it won't fit in 10 minutes I'll send you the source code of the "trainer" I'll try to write! OK?

[DarkInjection]

i have make some trainers with C with riteprocessmemory() etc but im writing more vb6 than C so i got a problem in C its not necessary to be something for games i just wanna find how to do it with C to change the assembly code in a memory adress i have done it with patch way but yea i wanna see how this can be with non-patch way and if i can inject some asm code more to the program without patch

[youhakim]

Gcc uses a line feed as the end of the line not a carriage return, line feed! it is Windows who uses carriage return, line feed.

Mac uses a carriage return.

sorry for the mistake!

[DarkInjection]

i like it...very simple

but only at&t syntax can we have?

[youhakim]

Thank you for taking time to leave a comment :)

You can generate if you want Intel syntax by adding the option -masm=intel when you compile the c code

gcc -S -masm=intel hello.c

Though gcc which relays on gas to do the assembling works natively with the AT&T syntax.