Hello World in x86 Assembly (32-bit macOS)

A minimal Hello World implementation in x86 32-bit assembly for macOS systems. This implementation uses BSD system calls through the macOS syscall interface.

Installation

macOS

Install the development tools:

xcode-select --install

For NASM installation:

brew install nasm

Building and Running

# Assemble
nasm -f macho hello.asm

# Link
# Note: macOS version minimum requirement helps ensure compatibility
ld -macosx_version_min 10.7.0 -o hello hello.o

# Run
./hello

Code Explanation

The implementation uses BSD system calls through macOS:

• write (4) outputs the message to stdout
• exit (1) terminates the program

The program follows macOS x86 32-bit syscall conventions:

• Arguments are pushed onto the stack
• Stack must be 16-byte aligned before syscalls
• System call number goes in EAX
• Syscall invoked with INT 0x80

Note that macOS has deprecated 32-bit support as of macOS Catalina (10.15). This code is primarily for educational purposes and historical understanding.