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

Computers in laboratory organisation and management, Computers can be used ...

Computers can be used for better and more efficient management and organisation of laboratories. A computer like the human brain receives information, stores and processes it and t

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

Processor, Processor: Processor plays major role in a computer. One sh...

Processor: Processor plays major role in a computer. One should carefully decide about the type of processor and its speed before making a choice. Currently Core 2 Duo process

Software design, Ineed help to do my homework which is for designing of req...

Ineed help to do my homework which is for designing of requirenments.

Socket, socket programming

socket programming

Stable marriage Problem, How to make a stale marriage program by implementi...

How to make a stale marriage program by implementing the Gale Shapley algorithm using Java program

Internet, Explain how the internet works

Explain how the internet works

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