School Commit Init

Anul 1/Semestrul 1/ASC/Seminar 5/2.asm

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+bits 32 ; assembling for the 32 bits architecture
+
+; declare the EntryPoint (a label defining the very first instruction of the program)
+global start        
+
+; declare external functions needed by our program
+extern exit,printf,scanf               ; tell nasm that exit exists even if we won't be defining it
+import exit msvcrt.dll    ; exit is a function that ends the calling process. It is defined in msvcrt.dll
+                          ; msvcrt.dll contains exit, printf and all the other important C-runtime specific functions
+import printf msvcrt.dll  ; printf is a function that prints a formatted string to the standard output
+import scanf msvcrt.dll   ; scanf is a function that reads a formatted string from the standard input
+
+; our data is declared here (the variables needed by our program)
+segment data use32 class=data
+    ; ...
+    read_number db "%d",0
+    a dd 0
+    b dd 0
+    message db "Sum=%d",0
+
+; our code starts here
+segment code use32 class=code
+    start:
+        ; ...
+        ; read a and b
+        push    dword a
+        push    dword read_number
+        call    [scanf]
+        add    esp, 4*2
+        push    dword b
+        push    dword read_number
+        call    [scanf]
+        add    esp, 4*2
+        ;print out the sum
+        mov    eax, [a]
+        add    eax, [b]
+        push    eax
+        push    dword message
+        call    [printf]
+        add    esp, 4*2
+        ; exit(0)
+        push    dword 0      ; push the parameter for exit onto the stack
+        call    [exit]       ; call exit to terminate the program