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

10, constant key use for in calculator

constant key use for in calculator

Arithmetic and logic unit, Arithmetic and Logic Unit: The Arithmetic a...

Arithmetic and Logic Unit: The Arithmetic and Logic Unit is that part of the CPU that actually performs arithmetic and logical operations on data. The CU, CPU registers and me

File management, explain the objectives of file management?

explain the objectives of file management?

How to find percentage in c++, I have written all formulas fine but still i...

I have written all formulas fine but still its showing 0 as percentage please help me in this program user have to enter obtain score and total score

Widening web, The Widening Web The idea, the whole world is agog...

The Widening Web The idea, the whole world is agog now had accidental origins. Here is how it all began. In early 1969, the U.S. Defence department financed a network fo

C program , write a c program of minimum shelf

write a c program of minimum shelf

Types of policy, want to get detail understanding of the types of security ...

want to get detail understanding of the types of security policies including enterprise security policy, issues specific policies etc

Function, function of arithmetic logic unit

function of arithmetic logic unit

Command processor and user interface, Command Processor and User Interface:...

Command Processor and User Interface: To the user, the most important and visible services provided by the OS is the user interface and the capabilities that it provides to ex

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