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

Defining conditional operator, Problem 1 What is conditional operator? ...

Problem 1 What is conditional operator? Using conditional operator find a smallest number between two numbers Defining conditional operator Using it to find smallest n

Ida* search-artificial intelligence, IDA* Search-Artificial intelligence: ...

IDA* Search-Artificial intelligence: A* search is a sophisticated and successful search strategy. yet, a problem with A* search is that it might  keep every states in its memor

Spreadsheet development, Basic steps/tasks involved in spreadsheets develop...

Basic steps/tasks involved in spreadsheets development

CAI, What is CAI? Explain its pitfalls.

What is CAI? Explain its pitfalls.

Medical counter/shop, Medical Counter/Shop The Software for medical co...

Medical Counter/Shop The Software for medical counter/shop should maintain: Complete customer Details  Inventory Control  Billing  Linked to Accounts  Have c

Q1, Write a half-page summary explaining IP spoofing.

Write a half-page summary explaining IP spoofing.

What do you mean by the term "robotics", Question 1 What do you mean by se...

Question 1 What do you mean by semantic networks? Explain inheritance in semantic networks Question 2 Explain Partitioned semantic networks with an example Question

Assignment, Hi I have an assignment can you help me ?

Hi I have an assignment can you help me ?

Html, a program to create htmlpage

a program to create htmlpage

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