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check my understanding of Assembly language

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ParkourPenguin
I post too much

Reputation: 152

Joined: 06 Jul 2014
Posts: 4719

Posted: Fri Nov 06, 2020 10:31 am Post subject:

Code:

alloc(stack,15)
...
alloc(stack2,25)

This is bad- allocs should ideally be specified in descending powers of 2, or at the very least in multiples of 8.

Code:

mov rax,[r8] // move the 4 bytes in memory at the address contained in r8 into rax

rax is an 8 byte register- that moves 8 bytes. If you only want to move 4, use eax.

Code:

mov [stack],r8 // move the contents in r8 into the 4 bytes at memory address stack

The stack alloc only needs 8 bytes (or 4 if you change rax to eax). I have no clue why you put 15.

Code:

push rbx // push rbx into the stack of "UserAssembly.dll"+10AC5C9

Stacks are associated with threads. I don't know what you try to convey with that address.

Code:

mov rbx,r8 // copies the content of r8 to rbx
add rbx,170 // adds 170 to the value stored in rbx
mov rbx,[rbx] // moves 4 bytes in memory at the address contained in rbx into rbx

This is needlessly complicated. Replace these 3 instructions with "mov rbx,[r8+170]".
And again, it's moving 8 bytes. Use ebx for 4 bytes.

Code:

mov [stack2],rbx // moves content of rbx to 4 bytes at memory address stack2

Moving 8 bytes here.

Code:

mov rbx,r8 //copies the content of r8 to rbx
add rbx,178 // add 178 to values stored in rbx
mov rbx,[rbx] //move the 4 bytes in memory at the address contained in rbx to rbx

Same mistake as before. Use "mov rbx,[r8+178]"; use ebx if you want to move 4 bytes.

Code:

mov [stack2+8],rbx // moves the content contained in rbx to the 4 bytes at the memory address stack+8

This is moving 8 bytes. Also, stack2 only needs to be 16 bytes in size.

Code:

pop rbx // removes rbx from "UserAssembly.dll"+10AC5C9

No clue why you think that address is relevant to push/pop.

Code:

movzx ecx,byte ptr [rdx+00000104]

I'm guessing this is part of the original code.

Code:

Jmp address+17 //jump to address + 17

Whoever wrote this should stop writing code and follow the default template as much as they can. This is an incredibly stupid way of jumping back to the original code- leave it at "jmp return".

Code:

code:
mov rax,[r8]
movzx ecx,byte ptr [rdx+00000104]
jmp return

If you're not going to use this, get rid of it.

Code:

registersymbol(address)

Minor detail: organize your code better and put this with the other allocs / registersymbols.
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ParkourPenguin
I post too much

Reputation: 152

Joined: 06 Jul 2014
Posts: 4719

Posted: Fri Nov 06, 2020 4:35 pm Post subject:

zbobfrank90 wrote:

so the push and pop have nothing to do with the address being injected but just adding to the thread of the memory address? am i right to say that the purpose of push and pop is to store the content in r8 to [stack2] and filter out so it contains only the coordinates of monsters/npc.

It seems like you've heard those words before but have no idea what they mean. (I'm not going to write a dozen paragraphs going over everything wrong with those couple sentences)

Whoever wrote that script doesn't know what they're doing. I would strongly encourage you to learn from some other source.
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OldCheatEngineUser
Whateven rank

Reputation: 20

Joined: 01 Feb 2016
Posts: 1586

Posted: Sun Nov 08, 2020 7:33 pm Post subject:

it means multiply.

8 multiplied by the content of rax plus content of r11.
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