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

Spreadsheet software , Spreadsheet Software : Consider the grid in Fig. ...

Spreadsheet Software : Consider the grid in Fig. 9.4. It is split into rows and columns and is a pictorial representation of a typical spreadsheet program.  Figure: Spr

What is Semaphore and explain with example?, Description A semaphore is a...

Description A semaphore is a confined variable whose value can be accessed and changed only by the operations P and V and initialization operation known as ''Semaphoiinitislize''.

GNF, what does it means

what does it means

Telecommunication networks architecture, Telecommunication Networks Archite...

Telecommunication Networks Architecture is the manner in which the components of thenetwork are organized and integrated to provide telecommunication services to users ofthe netwo

IF.ELSE Statement of python , Conditional constructs are used to integrate ...

Conditional constructs are used to integrate decision making into programs. The outcome of this decision making determines the series in which a program will execute instructions.

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

cpp programming assignment help, wrap that computes a customer water bill....

wrap that computes a customer water bill. The bill include Rs.100 water demand charge + a consumption charge of Rs.1.5 for every thousand gallons used. Consumption is figured from

Education and society, mention the aims of education in present scenario

mention the aims of education in present scenario

Device drivers, Device Drivers:   Device drivers are shared computer p...

Device Drivers:   Device drivers are shared computer programs that provide an interface between the hardware devices and operating system or other higher level programs.

Write a note on file permissions on linux, Question 1 Write a note on a...

Question 1 Write a note on advantages and disadvantages of Linux 2 Write a note on "File Permissions" on linux 3 Explain the usage of following Linux commands Cd kill

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