Question

1. Follow the instructions below to create a full running Assembly program:

   Create a ​WORD ​sized array with ​5​ elements of ​A2D5h ​using the ​DUP​ operator. Move the ​OFFSET ​of this array into register ​ESI​. Move the number of elements in the array initialized using the ​LENGTHOF​ instruction and move it into ECX as your loop counter.

   Create a ​LOOP​ that adds the value 1F33h to each element. Traverse through the array by adding the size of each element to the ​ESI​ using the instruction ​TYPE​.

   Using instructions, ​MOVZX​ and M​ OVSX​, move an element in the array into an appropriate sized register. After perform an swap of these two registers using the instruction ​XCHG. ​Lastly, utilize the instruction ​PTR​ to move an element from the array to a DWORD sized register.

Answer 1

SECTION . DATA

ARR DWORD 5 DUP(A2D5h)

ARR_SIZE EQU $ -ARR ; gives number of elements in which array.

SECTION .TEXT

global MAIN; must be declared for linker ( ld)

MAIN:

MOV ESI, ARRAY1 ; moves the offset of the array into ESI

MOV ECX, ARR_SIZE ; mov array size into ecx to act as the loop counter.

MOV EBX, 1F33h. Storing the data to be added in EBX.

SUM_UP:

ADD [ESI],EBX ;adding each element of the array with 1F33h.

ADD ESI,1 ; increment array address to pont the next element in the array.

DEC ECX ; Decrement loop counter.

JNZ SUM_UP ;jump to sum_up if counter not equal to zero.

MOVZX EAX, [ESI] ; moving array element into 32 bit register.

MOV EBX,[ESI-4] ; moves the previous array element to EBX.

XCHG EAX,EBX ;swap value in EAX with EBX

MOV EAX,DWORD PTR[ARR] ; An element of the array is moved EAX using PTR operator.