x86 Assembly(Intel)

C Boilerplate Decompilation

push rbp // push the main function to stack
mov rbp,rsp // sets up new stack frame for main function
sub rsp,0x10 // Allocate 16 bytes of stack space for local variables
mov DWORD PTR [rbp-0x4],edi // stores first argument 'argc' onto stack
mov QWORD pTR [rbp-0x10],rsi // stores second argument `argv` onto stack
mov %fs:0x28,%rax // stack smashing prevention
 
...
 
mov    eax,0x0 // return 0;
leave // pops old frame pointer off stack
ret // returns to main's initial address

Opcodes

• x86 Intel mov
• x86 Intel lea
• x86 Intel jmp
• x86 Intel nop

operation	Intel Syntax	pseudo demo
mov (move)	mov ebx, 123	ebx = 123
	Mov eax, ebx	eax = ebx
add	add ebx, ecx	ebx += ecx
sub	sub ebx, edx	ebx -= edx
mul (multiply)	mul ebx	eax = ebx
div	div edx	eax /= edx
int (interrupt)	Int 0	Check if program ended
	int 0x80	System call. Check if eax and abx register have cool values
jmp (jump)	jmp some_addr	Changes RIP to the address
nop(no operation)	nop	Do nothing
cmon (conditional move)	cmov ecx, eax	if ecx has the value true, then move address stored in eax