# rand_pt1.s 
    #
    # This is written for RARS
    #
    #   java -jar /home/mweeks/rars1_6.jar rand_pt1.s
    #
    # Print 20 random values.
    # 
    # -MCW

    .text
    main:
        # Note: we use s0 to make sure the value does not change 
        # when we do a call/ecall 
        li   s0, 20              # s0 holds the count
    
    myloop:
        call   get_rand          # get a random value
    
        # Now print the value (of a0) out
        li     a7, 1      # print an integer
        ecall
    
        # print space
        li    a0, 32     # space (the character to print)
        li    a7, 11     # print a character
        ecall           

        # Update s0 to count down
        addi   s0, s0, -1            
        bgt    s0, x0, myloop       # if greater or equal, jump to myloop
    
        # print NL
        li    a0, 10     # NL (the character to print)
        li    a7, 11     # print a character
        ecall           
        
        # exit the program
        li     a0, 0                # 0 for everything is OK
        li     a7, 93
        ecall

    get_rand:
        la    t2, lfsr        # t2 = address of "lfsr"
        lw    t3, 0(t2)       # t3 = word at "lfsr"

        # Need to add code here:
                              # shift t3 left by 11 bits
                              # lfsr = lfsr xor shift result
        
                              # shift it right by 7 bits
                              # lfsr = lfsr xor shift result
    
                              # shift it left by 12 bits
                              # lfsr = lfsr xor shift result
                              # store t3 into "lfsr"

        mv    a0, t3          # a0 = t3 to return
        ret


    .data       # Data section, initialized variables

    lfsr:      .word  1