How can I print numbers in my assembly program

Question

I have a problem with my assembly program. My assembly compiler is NASM. The source and the outputs are in this picture:

The problem is that I can't print numbers from calculations with the extern C function printf() . How can I do it?

The output should be "Ergebnis: 8" but it isn't correct.

Answer 1

In NASM documentation it is pointed that NASM Requires Square Brackets For Memory References . When you write label name without bracket NASM gives its memory address (or offset as it is called sometimes). So, mov eax, val_1 it means that eax register gets val_1 's offset. When you add eax, val_2 , val_2 offset is added to val_1 offset and you get the result you see.

Write instead:

mov eax, [val_1]
add eax, [val_2]

And you shoul get 8 in eax.

PS It seems that you have just switched to NASM from MASM or TASM . There are a lot of guides for switchers like you. See for example nice tutorials here and here .