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

Communications programs , Communications Programs : By communications prog...

Communications Programs : By communications programs, we mean those programs which allow a computer to communicate via a transmission cable to another electronic device. Here we d

Command Line Arguments, You may have seen, as, that many programs can be ru...

You may have seen, as, that many programs can be run so that they give you with some basic information concerning how they should be run. Python permits you to do this with -h: $ p

C++ programming, write a program of 2 sum and 2 product number in C++ progr...

write a program of 2 sum and 2 product number in C++ programming language

Special-purpose and general-purpose computers, SPECIAL-PURPOSE AND GENERAL-...

SPECIAL-PURPOSE AND GENERAL-PURPOSE COMPUTERS In general, there are two types of digital computers. The first is the special-purpose digital computer, which performs a f

Acting Rationally - artificial intelligence, Acting Rationally: Al Capo...

Acting Rationally: Al Capone was finally convicted for tax evasion. Were the police acting rationally? To answer this, we must first look at how the performance of police force

In-door patient department, In-door Patient Department Ideally all ...

In-door Patient Department Ideally all features of OPD.  Both OPD and IPD modules should be inter-linked.  In addition all details pertaining to the patient's medica

Network control, Network Control, Engineering and Management Network co...

Network Control, Engineering and Management Network control in this sense involves traffic management, and the engineering of the networks to support varying traffic loads. In

Problem solving using a computer, PROBLEM SOLVING USING A COMPUTER The ...

PROBLEM SOLVING USING A COMPUTER The following steps are required for solving a problem using a computer system:     Problem Definition     Program Planning (Preparati

Data buses, Data buses: The availability of reliable digital semi-condu...

Data buses: The availability of reliable digital semi-conductor technology has enabled the inter-communication task between different equipment to be significantly improved. P

Explanation of characteristics of computers, Problem 1. Briefly explain...

Problem 1. Briefly explain on the characteristics of computers Explanation of characteristics of computers 2. Write a note on Cache Memory Note on Cache Memor

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