Lets_build_a_compiler/LinuxAMD64/Assembly/push-pop.txt

Example of PUSH and POP

examen de la stack sous gdb :

x/10x $sp


Here’s a simple example of pushing and popping a value in x86-64 assembly:

[BITS 64]

section .text
    global _start   ; Entry point for the program

_start:
    mov rax, 42     ; Moves the value 42 into the rax register
    push rax        ; Pushes the value of rax onto the stack
    pop rbx         ; Pops the top value from the stack into rbx

    ; Exit the program
    mov eax, 60     ; syscall number for exit
    xor edi, edi    ; Exit code 0
    syscall         ; Invoke syscall to exit the program

In this example, we first moved the value 42 into the rax register. Then we pushed the value of rax onto the stack. We then popped the top value from the stack into the rbx register.

Finally, we use the syscall instruction to exit the program.



Autre programme :

[BITS 64]
section .bss
; nada
section .data
prompt:	db 'What is your name? '
prompt_length:	equ $-prompt
name: times 30 db 0
name_length: equ $-name
greeting: db 'Greetings, '
greeting_length: equ $-greeting
section .text
global _start
_start:
; Prompt the user for their name
mov rax, 1
; '1' is the ID for the sys_write call
mov rdi, 1
; '1' is the file descriptor for stdout and our
first argument
mov rsi, prompt
; prompt string is the second argument
mov rdx, prompt_length
; prompt string length is the third argument
syscall
; make the call with all arguments passed
; Get the user's name
mov rax, 0
; 0 = sys_read
mov rdi, 0
; 0 = stdin
mov rsi, name
mov rdx, name_length
syscall
push rax
; store return value (size of name) on the
stack... we'll need this for later
; Print our greeting string
mov rax, 1
; 1 = sys_write
mov rdi, 1
; 1 = stdout
mov rsi, greeting
mov rdx, greeting_length
syscall
; Print the user's name
mov rax, 1
mov rdi, 1
mov rsi, name
pop rdx
stored on the stack
syscall
; 1 = sys_write
; 1 = stdout
; length previously returned by sys_read and
; Exit the program normally
mov rax, 60
; 60 = sys_exit
xor rdi, rdi
; return code 0
syscall