Intelx86assembly-

Intel x86 assembly introductory tutorial for Reverse Engineering and Malware Analysis

For more in detail guide ,refer to following manuals

Reference Manuals

Intel Developer’s Manuals
Documentation Changes
Volume 1: Basic Architecture
Volume 2A: Instruction Set Reference A-M
Volume 2B: Instruction Set Reference N-Z
Volume 3A: System Programming Guide
Volume 3B: System Programming Guide
https://www.intel.com/products/processor/manuals/

There are two notations used in intel Assembly AT&T and Intel Syntax,I would use intel Syntax you can set it to intel in gdb by following command : set disassembly-flavor intel

Major difference is the source destination location and $ sign.For example

In AT&T :

• mov $4, %eax // GP register assignment
• mov $4, %(eax) // Memory assignment

But in Intel :

• mov eax, 4 // GP register assignment
• mov [eax],4 // Memory assignment

Regiters in x86

General purpose registers:EAX,ABX,ACX,ABX,ESI,EDI,EIP
Special purpose registers:ESP,EBP

32bits
	16 bits	8bits	8bits
EAX	AX	AH	AL
EBX	BX	BH	BL
ECX	CX	CH	CL
EDX	DX	DH	DL
ESI
EDI
EIP
ESP
EBP

AX = accumulator DX = double word accumulator CX = counter BX = base register SI = Source Index DI = Destination Index

LEA

The lea (load effective address) instruction is used to put a memory address into the destination. Syntax:lea destination, source : mov eax, [ebx+8] mostly used for printf in ghidra