What help with this Assembly language Subroutine, Basic Computer Science

Assignment Help:
Write an ARM subroutine which will extract a substring from a string. You will need to use the library routine malloc to allocate memory for the new string.

The subroutine signature is:
char * mysubstring( char string[], int start, int end ) ;

where char string[] is the string to extract the substring from; it is passed into the ARM routine as a pointer in a1 to the first element of the character (byte) array,
int start is the first character to extract from the string to the substring; it is passed into the ARM routine as a value in a2,
int end is the last character to extract from the string to the substring; it is passed into the ARM routine as a value in a3.
The return is a pointer to the new string.

#include
#include

extern char * mysubstring( char string[], int start, int end ) ;

int main( int argc, char * argv[] )
{
char tosub[] = "this is the string to substring" ;
char * result ; /* pointer to new string */

result = mysubstring( tosub, 12, 17 ) ;
printf( "String: %s\nSubstring: %s\n", tosub, result ) ;

exit( 0 ) ;

}

To use the library routine malloc you need to calculate the number of bytes of memory you are requesting, put that number in a1 and bl malloc. Upon return from the library routine a1 will have a pointer to the allocated memory.

You may assume that the start and end values are within the string and malloc returns a proper pointer value.

Related Discussions:- What help with this Assembly language Subroutine

Computer Networking Scenario help, The project designs a school computer la...

The project designs a school computer lab with the necessary hardware and software components along with the IP address for different components. The computer lab consists of one I

HACKER, Briefly explain who a hacker is and what the activities of a hacker...

Briefly explain who a hacker is and what the activities of a hacker are?k question #Minimum 100 words accepted#

How do you insert a symbol in a word document, Fundamentals of IT 1. Ho...

Fundamentals of IT 1. How do you insert a symbol in a Word document? 2. Explain absolute cell addressing? 3. Discuss Custom List? 4. Explain applications of Multimedia

Software Exploration, I need to review 2 different softwares one is windows...

I need to review 2 different softwares one is windows based and the other is Linux Based. Please Ask for further details

Geometric mean - algorithm, The geometric mean is obtained by multiplying a...

The geometric mean is obtained by multiplying all the four numbers and taking the fourth root of the product. Let x 1 ,x 2 ,x 3  and x 4  be the given four numbers then geometric

Definition of Internal hardware interruptions, Internal interruptions are...

Internal interruptions are produced by convinced events which come during the execution of a program. These types of interruptions are handled on their totality by the hardware and

How to avoid race conditions with critical section?, • The key to preventi...

• The key to preventing problem involving shared storage is get some way to prohibit more than one process from reading and writing the shared data concurrently. That part of the p

Sql server management studio assignment, Department (DeptNo, DeptName, Offi...

Department (DeptNo, DeptName, Office, Phone) Employee (EmpNo, FirstName, LastName, JobTitle, HireDate, Salary, MgrNo, Deptno) Customer (CustNo, CompanyName, Street, City, State, Zi

What is vpn? list the different types of vpn, Question 1 What is routing? ...

Question 1 What is routing? Explain the principles of routing Question 2 Explain different types of server operations in Enterprise Networking Question 3 Briefly d

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