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

C LANGUAGE, WHAT DO MEAN BY ALGORITHM,HOW CAN ALGORITHM HELP TO WRITE BETTE...

WHAT DO MEAN BY ALGORITHM,HOW CAN ALGORITHM HELP TO WRITE BETTER COMPUTER PROGRAM ,WRITE AN ALGORITHM IN COMPUTER INTEREST

Cmis, how much it cost for 8 week class

how much it cost for 8 week class

Area of curve, Write a program to find the area under the curve y = f(x) be...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

About the faculty posts, is there any oppurtunity for a mca to teach mcasub...

is there any oppurtunity for a mca to teach mcasubjects online

Sma* search - artificial intelligence, SMA* Search-Artificial intelligence ...

SMA* Search-Artificial intelligence IDA* search is good from a memory point of view. actually it may  be criticised for not using enough memory - utilizing  more memory may inc

Process control management, Process Control Management:   A  process  ...

Process Control Management:   A  process  is an executing program. It is considered the standard unit of work within a computer system. Every executing program is treated as a

Assembly Language Project, Our instructor gave us a project in making a mec...

Our instructor gave us a project in making a mechanical game or simple device using assembly language, can anyone give me a an example of a project description for our proposal?

Need of operating system, Need of operating system: What kind of facil...

Need of operating system: What kind of facilities operating system provides to the users and programs: The operating system provides interfaces for the user (keyboard, m

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