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

Debugging, Debugging Once a program has been written, it has to ...

Debugging Once a program has been written, it has to be tested first to ensure that it is free of errors. It is very normal that any program written will contain mistake

The terms ''row-major order'' and ''column-major order", What is meant by t...

What is meant by the terms 'row-major order' and 'column-major order'? Ans: (i) Storing the array column by column is called as column-major order and storing the array row by

Electronic transmission frequency, Electronic  transmission Frequency: ...

Electronic  transmission Frequency: Frequency is the rate at which a wave or cycle alternates between high and low (analog mode) or on and off (digital mode). For example, the

Explain Processes Vs Threads?, In many respect threads operate in the simil...

In many respect threads operate in the similar way as that of processes. A number of the similarity and differences are: Similarities • Similar to processes threads share CPU and o

Right click on a folder, I want the detailed theory about the options which...

I want the detailed theory about the options which occur when we right click on a folder.

Discuss the usage and benefits of storyboarding, Question 1 Discuss the us...

Question 1 Discuss the usage and benefits of storyboarding Question 2 Explain the different stages of scriptwriting Question 3 Explain the 12 fundamental principle

Consistency or data in dbms, Consistency or data in DBMS Consistency - da...

Consistency or data in DBMS Consistency - data in DBMS(Database) is accurate in modeling real world, follows integrity constraints User may ensure transaction consistent by itsel

Array, Array: Array  :  In programming, when large amount of related d...

Array: Array  :  In programming, when large amount of related data needs to be processed and each data element is stored with different a variable name, it becomes very diffic

Satellite transmission, Satellite Transmission: Satellites use microwa...

Satellite Transmission: Satellites use microwave frequencies and techniques. Satellites used for message transmission (as opposed to those, which travel around the earth on st

What is Decode or execution cycle?, just the once the instruction has bee...

just the once the instruction has been fetched and is accumulated, the next step is to decode the instruction so as to work out what actions should be performed to execute it. This

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