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

COMPUTER, DUNIYA KA AISA KONSA KOMPUTER HAI. JISME KEYBORD, MOUSE NAHI HAI?...

DUNIYA KA AISA KONSA KOMPUTER HAI. JISME KEYBORD, MOUSE NAHI HAI?

Potential risks to information systems, Question 1 Write about Pot...

Question 1 Write about Potential Risks to Information Systems Factors to be addressed for making information systems more secure Question 2 Write about the foll

Help for final project, Hello i am a computer science student. now we are g...

Hello i am a computer science student. now we are going to start our final project. we want to work on Google App Inventor and we want to create mobile application. we are two grou

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

Output, what is output and input

what is output and input

OPERATING SYSEMS, Design an ER diagram for an IT training group. The compan...

Design an ER diagram for an IT training group. The company has 12 instructors and can handle upto 100 trainees for each training section. The company offers 5 advanced technology c

File management, explain the objectives of file management?

explain the objectives of file management?

Drawing Karnaugh Maps, Where can I get free software for drawing K maps

Where can I get free software for drawing K maps

Global positioning system, How does GPS work in the field of Sport or athle...

How does GPS work in the field of Sport or athletics?

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