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

Java, what is meant by deliverable in strus base applications

what is meant by deliverable in strus base applications

Java programming, what are the phases of oo progarmming or java?

what are the phases of oo progarmming or java?

Telephobn directory, #que1) Create telephone directory. • The heading shoul...

#que1) Create telephone directory. • The heading should be 16-point Arial font in bold • The rest of the document should use 10-point font size • Other headings should use 10-point

C++, whats the out put of int main(){ int n=310; funcone(n); functwo(&n); ...

whats the out put of int main(){ int n=310; funcone(n); functwo(&n); cout return 0; } void funcone(intn) n=240; } void func two(intn*) { n=120; }

Server, Server In a network, the resources of computers comprising net...

Server In a network, the resources of computers comprising network are usually shareable. In fact, one of the main objectives of networking is to make the computing resources

Internal structure of agents - artificial intelligence, I n t e rnal St...

I n t e rnal Structure of Agents We have looked at agents in terms of their external influences and behaviors: they take input from the environment and perform rational act

C program, #write a c program to print ant and rod #

#write a c program to print ant and rod #

General considerations for search - artificial intelligence, General Consid...

General Considerations for Search If we may specify the starting state, the operators and the goal check for a search problem, then we know from where to start, how to move and

Pep8, Write an Assembly program that reads an integer (-32,768 through 32,7...

Write an Assembly program that reads an integer (-32,768 through 32,767) in decimal and prints its equivalent in binary. The output must show all 16 bits. And you must use a loop

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