MIPS运行时错误“无法直接写入文本段”以进行字符串反转

Question

我正在研究MIPS中的字符串逆转程序，对于MIPS / Assembly的内部工作方式我基本上一无所知。我在第36行遇到运行时错误，循环中有“sb $ t6，stringreverse（$ t3）”行。有人能解释一下吗？

.data
nl: .asciiz "\n"
inputPrompt: .asciiz "Please enter an integer:\n"

theString: .space 32
theInteger: .word 1

.text
main: 
la $a0, inputPrompt #load address a0 with prompt
li $v0, 4       #load system call, print string into v0
syscall 

li $v0, 5       #load system call, read int into v0
syscall
sw $v0, theInteger  #store saved int into $t0

li $v0, 8           #load system call, read string with mem address
la $a0, theString   #load address of reserved string space
lw $a1, theInteger  #load address of saved int length for string    
syscall

lw $t0, theInteger
add $a1,$zero,$t0   #pass lenght of string
jal stringreverse   #reverse the string

stringreverse:
add $t0,$a0,$zero   #starting address
add $t1,$zero,$zero     
add $t3,$zero,$zero     #i = 0
addi $t2,$a1,-2     #j = length-1

loop:
add $t5,$t0,$t2
lb $t6,0($t5)   #the lb string[j]
sb $t6,stringreverse($t3)
addi $t2,$t2,-1     #j--
addi $t3,$t3,+1     #i++

slt $t7,$t2,$t1
beqz $t7,loop

exit:
li $v1, 4       #system call to print reversed string
la $a2, 0($a1)
syscall

li $v0, 10
syscall         # Exit program