MIPS Fibonacci problem

[XodoX]

I'm still a beginner, so please bear with me;) I'm supposed to write a code that generates the Fibonacci series.
Here is the sample program output:

Please enter n (This program generates 0 to Fn) : 5
0 1 1 2 3 5

So, that's what I did..

.data
in_string:	.asciiz		"Input a positive integer:\n\n"
out_string:	.asciiz		"The Fibonacci number is:\n\n"


		.text
main:
	# print out prompt
		li	$v0, 4			# system call code for printing string = 4
		la	$a0, in_string		# load address of string to be printed into $a0
		syscall				# call operating system to perform print operation

	# read integer into $s0
		li	$v0, 5			# system call code for read integer = 5
		syscall				# call operating system
		move	$s0, $v0		# value read from keyboard returned in register $v0; transfer to $s0

		sw	$s0,($sp)		# push argument for Fib on stack
		addi	$sp,$sp,-4		#   and decrement stack pointer
		jal	Fib			# jump to subroutine
		addi	$sp,$sp,4		# increment stack pointer
		lw	$s1,($sp)		#   and pop result from stack
		
	# print out prompt
		li	$v0, 4			# system call code for printing string = 4
		la	$a0, in_string		# load address of string to be printed into $a0
		syscall				# call operating system

	# print out result (stored in $s1)
		li	$v0, 1			# system call code for printing integer = 1
		move	$a0, $s1		# move integer to be printed into $a0:  $a0 = $s1
		syscall				# call operating system to perform print

	# exit program
		li	$v0, 10			# system call code for exit = 10
		syscall				# call operating system

However, this is recursive.. I now read that it is supposed to be a non-recursive implementation. I don't know, I thought that's how you do it. How would I do non-recursive.
It's also supposed to be for positive integers only. I can't compile it on my computer right now, ut I think that's what it is ( at least should be) doing.

Any input is appreciated!!