Question

Hi i trying to make a loop in Nasm. I have the loop working but want to change the string when it loops and cant seem to get this to work.

I have this working:

main:
        mov ebx,0               ; set ebx to 0 
       myloop:                  ;
       inc ebx                  ;
       mov [msg], 2Ah           ;  Immediate move * to msg
       mov eax, 2Ah             ;
       push ecx                ; save ecx as printf uses it
       push OFFSET msg         ; parameter used by printf
       call printf             ; print string msg
       add esp, 4              ; remove  pointer to msg
       pop ecx                 ; restore ecx
        cmp ebx,[len]           ;
         jl myloop                  ;
       ret


.DATA

msg    db  "Hello, World+!", 0Ah, 0  ; 0A cariage return
                                     ; 0  end of string
star BYTE 2Ah ; 2A (hex) = Ascii *
len   equ $ - (msg +1)               ; length of string msg
 end

and it outputs *ello, World! the right number of times but i want it to output this

*ello, World!
**llo, World!
***lo, World!
****o, World!

and so on.

Can anyone help me please.

I must also note that it is linked to a C library to use printf for out put.

Answer 1

I won’t comment it

SECTION .data
msg     db  "Hello, World+!", 0Ah, 0  
len     equ $ - msg - 2

SECTION .text 
main:
    xor     ebx, ebx
    mov     esi, msg

    push    esi
    call    printf
    add     esp, 4 
.DoStar:
    mov     byte [esi + ebx], 2Ah
    push    esi
    call    printf
    add     esp, 4 

    inc     ebx
    cmp     ebx, len
    jne     .DoStar
    ret