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

Internet searching, Internet searching:  The Internet consists of mill...

Internet searching:  The Internet consists of millions of private/public/academic/business and government networks having local to global scope. It has billions of web pages o

Desk top publishing program, Desk Top Publishing Program: Desktop publ...

Desk Top Publishing Program: Desktop publishing programs contain many of the features of word processing software, but .go even further in the ability to layout the format of

Widening web, The Widening Web The idea, the whole world is agog...

The Widening Web The idea, the whole world is agog now had accidental origins. Here is how it all began. In early 1969, the U.S. Defence department financed a network fo

Read world population data file. store the values in multipl, Read World Po...

Read World Population Data File. Store the values in multiple vectors. Sort them by most populated region and output the results ext file is here : please">http://www.csupomona.

Explain master slave j-k flip flop, Question 1 Convert the following binar...

Question 1 Convert the following binary numbers to its specified number system 1101.11 (2) to octal 1111 (2) to decimal 110.11 (2) to hexadecimal 1011.11 (2) to

Telephobn directory, #que1) Create telephone directory. • The heading shoul...

#que1) Create telephone directory. • The heading should be 16-point Arial font in bold • The rest of the document should use 10-point font size • Other headings should use 10-point

Describe counting instructions, They are used to reduce or enlarge the cont...

They are used to reduce or enlarge the content of the counters. DEC INC DEC INSTRUCTION Idea: To diminish the operator. Syntax: DEC destiny This action subtracts 1 from the destiny

Cryptography, #questionConsider the one-time pad encryption scheme to encry...

#questionConsider the one-time pad encryption scheme to encrypt a 1-bit message m, and assume m is chosen with uniform distribution from message space M={0,1}. Let E1 be the event

Flowchart looping, create a flowchart showing average score for the 3 quizz...

create a flowchart showing average score for the 3 quizzes assume that there are 3 sections each having 5 students the only valid number to be entered is 1-100 for the quizzes shou

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