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

Artificial intelligence agents, Artificial Intelligence Agents In the ea...

Artificial Intelligence Agents In the earlier teach, we discussed what we will be talking about in Artificial Intelligence and why those tasks are important. This lecture is all

Cppm, sum of first 100 integers

sum of first 100 integers

Describe different kinds of registers used for register arra, Different kin...

Different kinds of registers are general between most microprocessor designs. These are: Program Counter (PC) This register is utilized to hold the memory address of the next instr

Create a database in access, The following are required: Create a ...

The following are required: Create a project in Access.  Your database must have flow and a theme. The database must be normalized.  The content m

Digitalelectronics, what duality principle and huntington postulates

what duality principle and huntington postulates

Outdoor patient department features - a doctor module, A Doctor Module ...

A Doctor Module Doctor has a list of the patients waiting for consultation. The doctor's module should include all the following details: Fields for common complaint

What is Assembly Language?, Assembly language is fundamentally the local la...

Assembly language is fundamentally the local language of your computer. In principle the processor of your machine understands machine code (consisting of ones and zeroes). But wit

Dfd, best example of dfd?

best example of dfd?

Working of web browser, Working of web Browser:   Internet is character...

Working of web Browser:   Internet is characterized by the Client Server Computing that consists of three basic components: The Web client which may be the web browser;

Language of digital computers, Language of Digital Computers: Digital ...

Language of Digital Computers: Digital computers are electronic devices which operate on two valued logic (On and OFF). The ability of a transistor to act as a switch is the k

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