.text
.global main               # must be declared for linker (ld)

.func main
main:                      # tells linker entry point
    mov $len, %edx         # message length
    lea msg(%rip), %rsi    # message to write (RIP relative addressing)
    mov $1, %edi           # file descriptor (stdout)
    mov %edi, %eax         # system call number (sys_write)
    syscall

    ret

.data
msg: .ascii "Hello, world!\n"
len = . - msg              # length of the msg string

%.o: ../%.S
	@echo 'Building file: $<'
	@echo 'Invoking: GCC Assembler'
	as -g --gstabs -o "$@" "$<"
	@echo 'Finished building: $<'
	@echo ' '