Lab4.lst

     1                                  bits 32 ; assembling for the 32 bits architecture
     2                                  
     3                                  ; declare the EntryPoint (a label defining the very first instruction of the program)
     4                                  global start        
     5                                  
     6                                  ; declare external functions needed by our program
     7                                  extern exit , printf, scanf ,strtok ,strlen       ; tell nasm that exit exists even if we won't be defining it
     8                                  import exit msvcrt.dll    ; exit is a function that ends the calling process. It is defined in msvcrt.dll
     9                                                            ; msvcrt.dll contains exit, printf and all the other important C-runtime specific functions
    10                                  import printf msvcrt.dll
    11                                  import scanf msvcrt.dll
    12                                  import strtok msvcrt.dll 
    13                                  import strlen msvcrt.dll
    14                                  
    15                                  segment data use32 class=data
    16                                      ; ...
    17                                      
    18 00000000 256200                      format db "%b",0
    19 00000003 256400                      format_ db "%d",0
    20                                  
    21                                  segment code use32 class=code
    22                                      start:
    23                                          ; ...
    24 00000000 50                              push dword eax
    25 00000001 68[00000000]                    push dword format
    26 00000006 FF15[00000000]                  call [scanf]
    27 0000000C 83C408                          add esp , 4*2
    28                                          
    29 0000000F 50                              push dword eax
    30 00000010 68[03000000]                    push dword format_
    31 00000015 FF15[00000000]                  call [printf]
    32 0000001B 83C408                          add esp , 4*2
    33                                          
    34                                          ; exit(0)
    35 0000001E 6A00                            push    dword 0      ; push the parameter for exit onto the stack
    36 00000020 FF15[00000000]                  call    [exit]       ; call exit to terminate the program
    37