I have code that I know works (it was from my professor) but I don't really understand where I 'm supposed to see the program output. I see the registers changing and such (not that I follow it completely) but the program is supposed to ask the user to input a value and I see no way that it is doing this. There is no window popping up to ask me for a value, and QtSpim seems to just be sitting there. I hit run, and step through, but nothing happens.
Here is the code:
# Sample spim program
#
.data
prompt: .asciiz "Enter in an integer: "
str1: .asciiz "the answer is: "
newline: .asciiz "\n"
bye: .asciiz "Goodbye!\n"
.globl main
.text
main:
# initialize
li $s0, 10
# prompt for input
li $v0, 4
la $a0, prompt
syscall
# read in the value
li $v0, 5
syscall
move $s0, $v0
loop:
# print str1
li $v0, 4
la $a0, str1
syscall
# print loop value
li $v0, 1
move $a0, $s0
syscall
# print newline
li $v0, 4
la $a0, newline
syscall
# decrement loop value and branch if not negative
sub $s0, $s0, 1
bgez $s0, loop
# print goodbye message
li $v0, 4
la $a0, bye
syscall
jr $ra # retrun to caller
Screenshot of my QtSpim. Lower left hand corner says 'Running'.. but where?