learn,how to mix C and Assembly Language ?, Basic Computer Science

learn,how to mix C and Assembly Language ?, Basic Computer Science

Assignment Help:

The technique to mix C and assembly language is to apply the "asm" directive. To access C-language variables from assembly language, you just use the C identifier that name is a memory operand. These variables cannot be local to a procedure, and also cannot be static within a procedure. They have to be global (but can be static global). The newline characters are essential.
unsigned long a1, r;
void junk( void )
{
asm(
"pushl %eax \n"
"pushl %ebx \n"
"movl $100,%eax \n"
"movl a1,%ebx \n"
"int $59 \n"
"movl %eax,r \n"
"popl %ebx \n"
"popl %eax \n"
);
}

This instance does the following:
1. Pushes the value stored in %eax and %ebx onto the stack.
2. Puts a value of 100 into %eax.
3. Copies the value in global variable a1 into %ebx.
4. Executes a software interrupt number 59.
5. Copies the value in %eax into the global variable r.
6. Restores (pops) the contents of the temporary registers %eax and %ebx.

Related Discussions:- learn,how to mix C and Assembly Language ?

Introduction to computer technology, excel grade book

excel grade book

Chat, Chat: The word chat in English language means - casual conversat...

Chat: The word chat in English language means - casual conversation. On Internet it means the same, except that you need to use text and your keyboard skills are tested. Earli

10, constant key use for in calculator

constant key use for in calculator

Quotation in Python, Python allows single (''), double (") and triple (''''...

Python allows single (''), double (") and triple ('''''' or """) quotes to indicate string literals, as long as the similar type of quote starts and ends the string. The triple quo

What is fragmentation?, Question 1 What is fragmentation? Question ...

Question 1 What is fragmentation? Question 2 Discuss the various service classes defined by integrated services Question 3 What are congestion? .Mention two algori

Operating system (o.s), Operating System (O.S) An operating syst...

Operating System (O.S) An operating system is the complete set of programs written to utilize the computer resources in an optimal manner. The operating system supervise

Cathode ray tube monitors, Cathode Ray Tube Monitors (CRT): Monitors d...

Cathode Ray Tube Monitors (CRT): Monitors display what is going on in your computer. They can run at various resolutions. It is the part of computer which looks like a TV set.

Initialization, what is its syntax

what is its syntax

List two i/o virtualization methods, Question 1 List two I/O virtualizatio...

Question 1 List two I/O virtualization methods. Based on different features compare these two methods Question 2 Discuss three areas considered by organizations to secure the

System administration and linux/unix, Write a system using script written i...

Write a system using script written in asuitable scripting language to automate taking a basic linux server instance and provisioning it with particular applications based on its I

Write Your Message!

Name

Email id

Message

Verfication Code

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!

Submit Assignment

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd