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 ?

Define Multilevel Queue Scheduling?, • A multilevel queue scheduling algori...

• A multilevel queue scheduling algorithm divides the ready queue in several separate queues, for example • In a multilevel queue scheduling processes are lastingly assigned to one

File management, File Management: The concept of a file is central t...

File Management: The concept of a file is central to the effective use of a computer system. A file is generally loosely defined as a collection of related information such

Differences between wcdma and gsm, Differences between WCDMA and GSM

Differences between WCDMA and GSM

Data processing, Data Processing In any computer-based system, d...

Data Processing In any computer-based system, data storage and retrieval plays an important role. Data storage involves decision about the encoding of data, assignment o

Graphs, Find the corresponding matrix of the digraph above

Find the corresponding matrix of the digraph above

Accessing folders and printers, Accessing Folders and Printers Accessi...

Accessing Folders and Printers Accessing folders, files and printers of another computer is as easy as accessing another computer. To access folders and printers of another c

Define the elements of contlor unit , The three main elements of the con...

The three main elements of the control unit are: 1. Decoder this is used to decode the instructions that create a program when they are being processed, and to establish in what ac

Mode of nutrition, what type of nutrition,leech is?

what type of nutrition,leech is?

CAI, What is CAI? Explain its pitfalls

What is CAI? Explain its pitfalls

Application software, Application Software: Application software is ...

Application Software: Application software is designed and developed to accomplish one or more specific task or solve a particular problem. Application software may be

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