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

Definition of resource sharing , Resource sharing is a concept which has de...

Resource sharing is a concept which has developed to contain many cooperative activities among libraries and other stakeholders. Interlibrary loan continues to be the basis of reso

Batch processing, Batch Processing When the entire computer system is d...

Batch Processing When the entire computer system is dedicated to a single job, the system is said to be operating in Batch Processing mode. In this mode each program is run to

Explain the functions of alu, Question 1 Write down the Booth's Multiplica...

Question 1 Write down the Booth's Multiplication Algorithm. Justify the Booth's Multiplication Algorithm Question 2 Explain the functions of ALU Question 3 Define the term ins

Quiz for your learning activity, The development of your learning module is...

The development of your learning module is very time consuming, so it is recommended that you begin creating your learning module during this first week. Before you begin, download

Grammar, Given the following grammar: -> [ , ] | -> | { } -> a...

Given the following grammar: -> [ , ] | -> | { } -> a | b | cwhich are the strings generated by the grammar? Show the parse tree(s). a). { [ a , b ] }b). [ { a } , b ]

Compare between file processing system and dbms, Problem a. Compare bet...

Problem a. Compare between file processing system and DBMS >>This is a comparison of DBMS with file processing system which the answer has to be searched from the GOOGLE an

What are the features of microprocessor ?, Previously two sections the fund...

Previously two sections the fundamentals of the workings and architecture of the central processing unit has been explained. There has been a common look at easy processor architec

Computer architecture, #formular for calculating speed up factor fo super s...

#formular for calculating speed up factor fo super scalar architecture, super pipeline architecture and VLIW with m different functional units.

How is the ack request formed, QUESTION a) The handling of the INVITE t...

QUESTION a) The handling of the INVITE transaction in SIP is completely different from the handling of other transactions. The handling of the INVITE is one of the most complex

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