x86 Assembly MASM --- For this programming assignment you will develop two assem

Question

x86 Assembly MASM

---

For this programming assignment you will develop two assembly language procedures that will be called from C. The C module is given to you. You will provide the assembly module containing the two procedures.

The C prototype for the first procedure is shown below.

void convertUpper(char* c);

convertUpper will receive a pointer to a character (i.e. the address). Here are the things convertUpper should do:

Check to see if the character is a lower case character. If not, return without doing anything.

Convert the character at the address to upper case.

The C prototype for the second procedure is shown next.

void convertLower(char c1, char c2, char c3, char c4, char c5, char c6, char c7);

convertLower will receive seven characters. The characters will be either alpha or numeric characters. If a character is an upper case alpha character, it should be converted to lower case. convertLower should do the following things:

Convert each of the seven characters to lower case if it is an upper case alpha character.

Call the C function, printChars, to print the seven characters after the conversion to lower case. printChars is given to you in the C source code file shown below.

The following source file contains the C code you will use to call the assembly procedures. You may modify the code for testing purposes.

You may not use the Microsoft directives PROTO and INVOKE for this assignment.

Details on how to go about this assignment would be greatly appreciated.

C code below

--------------------------

#include <stdio.h>

// C prototypes for the functions written in assembly language
void convertUpper(char* c);
void convertLower(char c1, char c2, char c3, char c4, char c5, char c6, char c7);

// Main -------------------------------------------------------------------
int main()
{
   char lowerChar = 'a';
   char upperChar;
   char c1 = 'C', c2 = 'S', c3 = 'C', c4 = 'I', c5 = '2', c6 = '1', c7 = '2';

   upperChar = lowerChar; // Copy the character to be converted
   convertUpper(&upperChar); // Convert character to upper case
   printf("lower = %c, upper = %c ", lowerChar, upperChar); // Print result

   // Convert seven characters to lower case
   convertLower(c1, c2, c3, c4, c5, c6, c7);

   return 0;
}

//------------------------------------------------------------------
// Description: Prints the seven characters that are passed to it
// Receives: Seven characters
// Returns: Nothing
void printChars(char c1, char c2, char c3, char c4, char c5, char c6, char c7)
{
   printf("%c%c%c%c%c%c%c ", c1, c2, c3, c4, c5, c6, c7);
}

==========================

I am not sure how to pass the char into my stack and keep my stack aligned and how to return the value. Please keep in mind, this, this procedure is called from an assembly file to C. I cannot use inline assembly.

My converUpper code is as follows:

.386
.model flat,C

.code

;-----------------------------------------------------
convertUpper PROC
   ; Function prolog
   push   ebp
   mov       ebp, esp
   ; Compute the result

   ;mov checkUpper, 0000000000000000000000000100000b   ;mask
   mov eax, 0000000000000000000000000100000b
   and eax, [ebp + 8]
   cmp eax, 0000000000000000000000000100000b
   jnz noConvert
   mov eax, [ebp + 8]
   xor eax, 0000000000000000000000000100000b
   nop
   mov [ebp +8], eax
   jmp upperEnd
noConvert:   mov eax, [ebp + 8]
           jmp upperEnd
   ; Function epilog
upperEnd:   nop
   pop       ebp
   ret       4  
convertUpper ENDP

END

Explanation / Answer

The assembly language program you need is here as follows:

upper.asm

.MODEL MEDIUM
.DATA
INP DB 10 DUP(' '),'$'
OUT DB 0DH,'Upper Case String is:$','$'
.CODE

MAIN PROC
MOV AX,@DATA
MOV DS,AX

LEA SI,INP
GOBACK:
MOV AH,01H
INT 21H
CMP AL,0DH
JE RETURN

CMP AL,41H
JL TRUNK
CMP AL,5AH
JG TRUNK
ADD AL,20H
TRUNK: MOV [SI],AL
INC SI
JMP GOBACK
RETURN:
MOV AL,'$'
MOV [SI],AL

MOV AH,09H
LEA DX,OUT
INT 21H

MOV AH,09H
LEA DX,INP
INT 21H

MOV AH,4CH
INT 21H

MAIN ENDP
END MAIN

Please rate the answer if it helped . .. Thankyou

Hope it helps..

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