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You can compile assembler programs using NASM on Linux or Windows, as NASM is available for both platforms. The NASM assembler will use mnemonics to convert low-level coding into machine language that the processor can understand. This article will not teach you how to program using NASM, but will teach you how to create executable commands for Linux and Windows from NASM source code.

Netwide Assembler (NASM) is an assembler and disassembler for the Intel x86 architecture, commonly used to create 16-bit, 32-bit (IA-32), and 64-bit (x86-64) programs.

How to compile assembly programs using NASM for Linux?

Creating Source Files

We can do this using any text editor such as Gedit, KWrite, or XEmacs. When you save the file, give it an .asm extension .

Compile source files

For this step, we need to install the NASM software on our computer.

If we are running Debian or Ubuntu, just type the following command:

$ sudo apt-get install nasm

If we have other Linux distributions, we must use the package manager of our distribution (such as Urppi, Yum, Emerge) or download NASM from the official website.

Use the following command line to compile the source file:

$ nasm -f elf test.asm

In the example, the saved .asm file is called test.asm . This will create a file called test.o in the current directory .

注意The file is not executable. It is still an object file.

Creating an Executable

Now that we have our object file, called test.o , we have to create our executable file.

Our program may _startstart as a procedure named . This means that our program has its own entry point, without the need to use mainthe function. However, we need to use "l" to create an executable file:

$ ld test.o -o test

Alternatively, our program can be mainstarted from a process called . We will need to use gccto create our executable:

$ gcc test.o -o test

Now our executable is created, tested, and located in the current directory.

Program Execution

To run a program named test , just type the following command:

$ ./test 

How to compile assembly programs using NASM for Windows?

There is no function under Windows main, and WinMain must be used instead.

If our entry point is _startor main, we should change it to _WinMain @ 16. Also, change the ret at the end of the procedure to ret 16:

section .text       
global _WinMain@16       
_WinMain@16:       
 mov eax, 0       
 ret 16 

Install the software

We must first install NASM. Save the installation package somewhere as we will need it later.

The most difficult step is to install MinGW , a free development environment for Windows:

Start by selecting the latest version of MingGW from their website. Run the installer, but do not update at this time. Leave all options selected by default, and wait for it to install.

Now you need to insert NASM in the development environment MinGW. Unzip the NASM archive. We should get a folder containing a file called nasm.exe . Copy this file to the directory C:\MinGW\bin .

Creating Source Files

As with Linux, you do not need to use a specific publisher to create source files for NASM. You can use Notepad. But be aware that it tends to add the .txt extension to the files it creates. To eliminate any ambiguity, it is recommended that you look at the file's extension.

At all costs, avoid using a word processor such as Word or WordPad.

If we prefer, we can also use an editor that uses NASM syntax, such as the NasmEdit IDE.

Make sure to save the source file with an .asm extension.

Compile source files

Open a Command window by going to Start > Run and typing cmd.exe

Using the command cd, go to the folder containing the source file. Once in this directory, assemble the source file (test.asm) using the following command:

> nasm -f win32 test.asm -o test.o

We have now created an object file. The next step will be to turn it into an executable file.

Program creation and execution

In the command window, type the final command to create the executable file:

> ld test.o -o test.exe