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 ?

Turn-around, The term ‘page traffic’ describes

The term ‘page traffic’ describes

Flowchart, create a flowchart showing average score for the 3 quizzes assum...

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

Search problems in artificial intelligence, Specifying Search Problems ...

Specifying Search Problems In our agent terms, a problem to be solved is a particular task where the agent starts with the environment in a given state and acts upon the enviro

Open source software, Open Source Software: Open Source Software (OSS)...

Open Source Software: Open Source Software (OSS) is software that comes with source code, and importantly also provides rights (typically reserved for copyright holders) to st

Device drivers, Device Drivers:   Device drivers are shared computer p...

Device Drivers:   Device drivers are shared computer programs that provide an interface between the hardware devices and operating system or other higher level programs.

Web browser, Web Browser:   A Web browser is software application that ...

Web Browser:   A Web browser is software application that enables you to find, retrieve, and display information available on the World Wide Web (WWW). Browser also allows you

Why is the atm selected as a transport network in 3g, Why is the ATM select...

Why is the ATM selected as a transport network in 3G? Answer: ATM provides efficient support for transmission of voice, data, and video ATM provides QoS guarantee and reliability

Rom, what is rom

what is rom

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