Question

Write a MIPS program to check if computer is a big-endian or little-endian system. This must be done in MIPS assembly language.

Answer 1

Greetings!!

Little endian:Lower byte of the data is stored at lower end of the memory.

Example,data 11223344 in a little endian machine is stored as:

2000:44

2001:33

2002:22

2003:11

Big endian:Lower byte of the data is stored at higher end of the memory

Example,data 11223344 in a little endian machine is stored as:

2000:11

2001:22

2002:33

2003:44

MIPS can use either little or big endian and is machine specific.

Code:

Logic used:First 1 word of data is stored and then read the data byte by byte along with the address and then observing the address and byte so that the endianess can be determined

.data

num: .word 0

message: .asciiz " is stored at address "

nl: .asciiz "\n"

.text

#STORE NUMBER 11223344 INTO MEMORY

li $t0,0x11223344

sw $t0,num

#GET THE ADDRESS OF THE MEMORY

la $t0,num

li $t2,0

loop:

beq $t2,4,end

#LOAD FIRST BYTE FROM THE MEMORY

lb $t1,0($t0)

#PRINT THE BYTE

move $a0,$t1

li $v0,1

syscall

#PRINT “IS STORED AT ADDRESS” MESSAGE

la $a0,message

li $v0,4

syscall

#PRINT THE BYTE ADDRESS

move $a0,$t0

li $v0,1

syscall

#PRINT NEWLINE

la $a0,nl

li $v0,4

syscall

addi $t0,$t0,1

addi $t2,$t2,1

#REPEAT

j loop

end:

#TERMINATION

li $v0,10

syscall

Screenshot:

Lower byte of the data is stored at the lower end of the memory and hence the system used little endian scheme.

[Please note that the output is in decimal and the corresponding hex values are given in red colour]

Hope this helps