Write this ARM assemble language program, Basic Computer Science

Assignment Help:
Programming Assignment
CS252 Spring 2014

Write an ARM assembly language subroutine that performs according to the following specification (Caesar cypher).

Given a mixed case alphabetic string from the C driver program, convert it to all upper case and create a new string for return to the C program. The new string has the characters from the old string replaced by upper case characters from the alphabet offset by the given amount in the alphabet.

If the character string is ‘Abc’ with an offset of -3 the new string would be ‘XYZ’. For characters in the alphabet such as ‘mno’, the alphabet is ‘JKL’. The beginning of the alphabet is wrapped to the end.

To convert a character to upper case, AND the character with 0xDF. Do not process the space character (leave it as a space) or the NULL byte terminator but be sure to include the NULL byte in the new string.

The C driver code:
/* C code for cipher */
#include
#include

extern char * cypher( char * s, int offset ) ;

int main( int argc, char * argv[] )
{
?char string[] = "The quick brown fox jumped over the lazy dog" ;
?char * result ;
?int offset = -5 ;

?result = cypher( string, offset ) ;
?printf( "Original:%s\n", string ) ;
?printf( "Coded: %s\n", result ) ;
?
?exit( 0 ) ;
}

The assembly routines definition is:
?extern char * cypher( char * s, int offset )
?where?char * s is the pointer to the string,
?int offset is the integer distance to move
?returns a pointer to a string.

To determine the length of the string in order to reserve space for the new string use the library routine strlen. Register a1 contains a pointer to the string to measure and on return register a1 has the number of characters in the string. You need to add one to this result since strlen does not account for the null byte at the end.
You can pass this length to the malloc library routine to obtain space for the new string.

Related Discussions:- Write this ARM assemble language program

Discuss the anatomy of xml document, Question 1 What is web browser? List ...

Question 1 What is web browser? List and explain the most common used web server Question 2 Discuss the anatomy of XML document Question 3 Discuss the various attr

Android database file not loading on real device, i have an android app whi...

i have an android app which uses a database file called question db which is stored in the assets file. I have tried a database example called android application development but f

Electronic digital, Design a BCD to excess 3 code converter using minimum n...

Design a BCD to excess 3 code converter using minimum number of NAND gates.

Java, function of void

function of void

Language of digital computers, Language of Digital Computers: Digital ...

Language of Digital Computers: Digital computers are electronic devices which operate on two valued logic (On and OFF). The ability of a transistor to act as a switch is the k

String problem, c program to convert S to palindromes with minimum number o...

c program to convert S to palindromes with minimum number of character replacements

Trap doors and Logic Bombs, Trap doors:  This is a way of bypassing normal...

Trap doors:  This is a way of bypassing normal authentication procedure (windows/ operating system user name  and password) to access a system. Once a system is compromised (impac

File organization, File Organization There are three types of fi...

File Organization There are three types of file organization used in practice. Let us consider the example of a dictionary. The dictionary contains listing of English wo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd