CODEWITHSUNDEEP
mips
Zaid Alyafeai
Zaid Alyafeai

Reputation: 155

Outputting the same string input

Suppose that I want to output the same string I inserted , I would use the following 

main:

la $a0,buffer #allocate space for $a0

li $v0,8 #read the string input 
syscall

li $v0, 4 #print the string input 
syscall

li $v0,10 #stop the program
syscall

Well, that wont work and I have to add 

li $a1,..

and I don't know why ?

Upvotes: 0

Views: 38

Answers (1)

Konrad Lindenbach
Konrad Lindenbach

Reputation: 4961

See the MARS/spim syscall doc here.

For syscall 8 you need to specify a buffer address in $a0 and a length in $a1. My guess is the code above doesn't work because the program starts off with $a1 preset to zero meaning that you will read in 0 bytes.

In addition, your comment on the first line is wrong. Using la does not allocate space. This should be done in the text segment where I assume the buffer label is defined. Using la only loads the address of the label buffer into a register.

Upvotes: 1

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