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, identify application software from the list? ms excel linux inter...

identify application software from the list? ms excel linux internet explorer adobe photshop sound card driver window disk manger adobe dream weaver windows file explorer

Artificial intelligence-specifying search problems, Specifying Search Probl...

Specifying Search Problems In our agent expressions, a problem to be solved is a specific task where the agent starts with the atmosphere in a given state and acts upon the env

Computer architecture, Write control sequence for adding the content of the...

Write control sequence for adding the content of the memory location whose address is at memory location pointed by immediate number NUM to register R1. Assume the number NUM is pr

DR Racket program, Hi, I''m looking for someone to help me with Computer Sc...

Hi, I''m looking for someone to help me with Computer Science ASAP. How soon are you available? Thanks! Specifically using the Racket program dealing with creating a list that will

Briefly explain the types of textures, Question 1 Describe the four compon...

Question 1 Describe the four components of light source Question 2 Briefly explain the types of textures Question 3 Explain the standard settings used to adjust th

Project, My son has a project assignment he has problem with. The only thin...

My son has a project assignment he has problem with. The only thing is, it is due in 20 mins. can someone be able to help him? if so, how much is the fee?

Turn-around, The term ‘page traffic’ describes

The term ‘page traffic’ describes

C++, whats the out put of int main(){ int n=310; funcone(n); functwo(&n); ...

whats the out put of int main(){ int n=310; funcone(n); functwo(&n); cout return 0; } void funcone(intn) n=240; } void func two(intn*) { n=120; }

Define z-transform of sequence x[n], QUESTION (a) Define z-transform o...

QUESTION (a) Define z-transform of sequence x[n]. (b) A causal LTI system has impulse response h[n], for which the z-transform is                     H(z) = (1+z -1

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