Just Downloaded QtSPim and I cannot run the first program

Question

I have to use QtSpim for one of my classes and I cannot run the program. When I downloaded QtSpim this is what was in the text section. If I try to run, I get the error beneath the code. I know where the error is, I don't know how to fix it and I cannot delete or change anything on the text screen

User Text Segment [00400000]..[00440000]
[00400000] 8fa40000  lw $4, 0($29)            ; 183: lw $a0 0($sp) # argc 
[00400004] 27a50004  addiu $5, $29, 4         ; 184: addiu $a1 $sp 4 # argv 
[00400008] 24a60004  addiu $6, $5, 4          ; 185: addiu $a2 $a1 4 # envp 
[0040000c] 00041080  sll $2, $4, 2            ; 186: sll $v0 $a0 2 
[00400010] 00c23021  addu $6, $6, $2          ; 187: addu $a2 $a2 $v0 
[00400014] 0c000000  jal 0x00000000 [main]    ; 188: jal main 
[00400018] 00000000  nop                      ; 189: nop 
[0040001c] 3402000a  ori $2, $0, 10           ; 191: li $v0 10 
[00400020] 0000000c  syscall                  ; 192: syscall # syscall 10 (exit) 

Kernel Text Segment [80000000]..[80010000]
[80000180] 0001d821  addu $27, $0, $1         ; 90: move $k1 $at # Save $at 
[80000184] 3c019000  lui $1, -28672           ; 92: sw $v0 s1 # Not re-entrant and we can't trust $sp 
[80000188] ac220200  sw $2, 512($1)           
[8000018c] 3c019000  lui $1, -28672           ; 93: sw $a0 s2 # But we need to use these registers 
[80000190] ac240204  sw $4, 516($1)           
[80000194] 401a6800  mfc0 $26, $13            ; 95: mfc0 $k0 $13 # Cause register 
[80000198] 001a2082  srl $4, $26, 2           ; 96: srl $a0 $k0 2 # Extract ExcCode Field 
[8000019c] 3084001f  andi $4, $4, 31          ; 97: andi $a0 $a0 0x1f 
[800001a0] 34020004  ori $2, $0, 4            ; 101: li $v0 4 # syscall 4 (print_str) 
[800001a4] 3c049000  lui $4, -28672 [__m1_]   ; 102: la $a0 __m1_ 
[800001a8] 0000000c  syscall                  ; 103: syscall 
[800001ac] 34020001  ori $2, $0, 1            ; 105: li $v0 1 # syscall 1 (print_int) 
[800001b0] 001a2082  srl $4, $26, 2           ; 106: srl $a0 $k0 2 # Extract ExcCode Field 
[800001b4] 3084001f  andi $4, $4, 31          ; 107: andi $a0 $a0 0x1f 
[800001b8] 0000000c  syscall                  ; 108: syscall 
[800001bc] 34020004  ori $2, $0, 4            ; 110: li $v0 4 # syscall 4 (print_str) 
[800001c0] 3344003c  andi $4, $26, 60         ; 111: andi $a0 $k0 0x3c 
[800001c4] 3c019000  lui $1, -28672           ; 112: lw $a0 __excp($a0) 
[800001c8] 00240821  addu $1, $1, $4          
[800001cc] 8c240180  lw $4, 384($1)           
[800001d0] 00000000  nop                      ; 113: nop 
[800001d4] 0000000c  syscall                  ; 114: syscall 
[800001d8] 34010018  ori $1, $0, 24           ; 116: bne $k0 0x18 ok_pc # Bad PC exception requires special checks 
[800001dc] 143a0008  bne $1, $26, 32 [ok_pc-0x800001dc] 
[800001e0] 00000000  nop                      ; 117: nop 
[800001e4] 40047000  mfc0 $4, $14             ; 119: mfc0 $a0 $14 # EPC 
[800001e8] 30840003  andi $4, $4, 3           ; 120: andi $a0 $a0 0x3 # Is EPC word-aligned? 
[800001ec] 10040004  beq $0, $4, 16 [ok_pc-0x800001ec]
[800001f0] 00000000  nop                      ; 122: nop 
[800001f4] 3402000a  ori $2, $0, 10           ; 124: li $v0 10 # Exit on really bad PC 
[800001f8] 0000000c  syscall                  ; 125: syscall 
[800001fc] 34020004  ori $2, $0, 4            ; 128: li $v0 4 # syscall 4 (print_str) 
[80000200] 3c019000  lui $1, -28672 [__m2_]   ; 129: la $a0 __m2_ 
[80000204] 3424000d  ori $4, $1, 13 [__m2_]   
[80000208] 0000000c  syscall                  ; 130: syscall 
[8000020c] 001a2082  srl $4, $26, 2           ; 132: srl $a0 $k0 2 # Extract ExcCode Field 
[80000210] 3084001f  andi $4, $4, 31          ; 133: andi $a0 $a0 0x1f 
[80000214] 14040002  bne $0, $4, 8 [ret-0x80000214]; 134: bne $a0 0 ret # 0 means exception was an interrupt 
[80000218] 00000000  nop                      ; 135: nop 
[8000021c] 401a7000  mfc0 $26, $14            ; 145: mfc0 $k0 $14 # Bump EPC register 
[80000220] 275a0004  addiu $26, $26, 4        ; 146: addiu $k0 $k0 4 # Skip faulting instruction 
[80000224] 409a7000  mtc0 $26, $14            ; 148: mtc0 $k0 $14 
[80000228] 3c019000  lui $1, -28672           ; 153: lw $v0 s1 # Restore other registers 
[8000022c] 8c220200  lw $2, 512($1)           
[80000230] 3c019000  lui $1, -28672           ; 154: lw $a0 s2 
[80000234] 8c240204  lw $4, 516($1)           
[80000238] 001b0821  addu $1, $0, $27         ; 157: move $at $k1 # Restore $at 
[8000023c] 40806800  mtc0 $0, $13             ; 160: mtc0 $0 $13 # Clear Cause register 
[80000240] 401a6000  mfc0 $26, $12            ; 162: mfc0 $k0 $12 # Set Status register 
[80000244] 375a0001  ori $26, $26, 1          ; 163: ori $k0 0x1 # Interrupts enabled 
[80000248] 409a6000  mtc0 $26, $12            ; 164: mtc0 $k0 $12 
[8000024c] 42000018  eret                     ; 167: eret 

Instruction references undefined symbol at 0x00400014 [0x00400014] 0x0c000000 jal 0x00000000 [main] ; 188: jal main

I tried to delete text or change things but I Can't. QtSpim is new to me and I don't know what to do now. I have re-downloaded QtSpim but nothing changed. Any help is appreciated

Answer 1

Looks like you haven't yet loaded a program into the simulator.

Here's one, put the following into a text file called "mips1.asm":

        .data
hw:    .asciiz "hello world\n"

       .text
main:
        la $a0, hw
        li $v0, 4
        syscall

        li $v0, 10
        syscall

Use "File" menu, select item "Reinitialize and Load File", and navigate to and pick this assembly text file to open in the simulator.

Then use menu "Simulator" "Single Step/F10" (your best friend) or "Run/Continue/F5".

Whenever you make a change to the assembly text file, use "Reinitialize and Load File" in QtSpim.

The other popular MIPS simulator, MARS is a bit more friendly, it has a built in editor with syntax highlighting, so developing some code is somewhat more of an IDE experience instead of using a separate MIPS unaware editor.