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

Explain the tcp/ip reference model with diagram, Question 1 Define the fol...

Question 1 Define the following terms                                   1) Analog Signals and Digital Signals 2) Composite signals Question 2 Define the following terms

Development of UNIX , Development of UNIX: The original UNIX developme...

Development of UNIX: The original UNIX development was performed on a Digital PDP-7 minicomputer and later moved to a PDP-11 minicomputer, the forerunner of the VAX computer.

File sharing architecture, File Sharing Architecture:   The developmen...

File Sharing Architecture:   The development of microprocessor, PC and LAN transformed dumb terminals into -smart? clients. This brought a complete change in the computing env

Explain the important features of creational patterns, Question 1 Explain ...

Question 1 Explain the role of object oriented designers in developing a software system Question 2 What are the four essential elements of design patterns? Explain Question 3

Artificial intelligence, Artificial Intelligence Artificial Intelligen...

Artificial Intelligence Artificial Intelligence is difficult science to explain, as it has fuzzy borders with  computer science, mathematics,  philosophy, physics,  psychology

Describe circuit switching and message switching, Question 1 List the Basi...

Question 1 List the Basic essential components of a computer network Question 2 What are the functions of (i) Routers (ii) Bridges Question 3 What are the advantag

Importance of good database design , Importance of Good Database Design Poo...

Importance of Good Database Design Poor database design may have results in unwanted data redundancy Poor database design keeps errors leading to bad decisions and results Practica

E-learning, E-learning: E-learning is one of the most used terms on th...

E-learning: E-learning is one of the most used terms on the Internet that describes any form of learning that is facilitated academically by the electronic means. Such means m

Java - Stack and Queue, Consider a class called Configuration. This class “...

Consider a class called Configuration. This class “encapsulates” the configuration management for any software system. For example, once created, the user can simply ask the config

Definition of assembler structure, In assembly language code lines have t...

In assembly language code lines have two fractions, the earliest one is the name of the instruction which is to be executed, and the next one are the parameters of the command. For

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