assemblymipsendiannessspim

MIPS XSPIM different endianess order confusion


As a first time MIPS user I seem to be confused. I have some classmate who have said that there XSPIM is big endian. However, in Linux it is little endian byte order. If MIPS can be little endian or big-endian. Is there a way to find out in XSPIM if it runs as little endian or big endian in your machine?


Solution

  • SPIM adopts the endian-ness of the machine on which it runs. (http://www.dsi.unive.it/~arcb/LAB/spim.htm#Byte%20Order)

    Here's a little program to check the endian-ness of your machine:

    .data
    word:      .word 1
    bigStr:    .asciiz "Big Endian\n"
    littleStr: .asciiz "Little Endian\n"
    
    .text
    
    main:
    
    la $t0 word
    lb $t1 0($t0)
    
    beqz $t1 bigEndian
    
    littleEndian:
    
        la $a0 littleStr
        addi $v0 $zero 4
        syscall
    
        jr $ra
    
    bigEndian:
    
        la $a0 bigStr
        addi $v0 $zero 4
        syscall
    
        jr $ra