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 ?

What is the difference between kernel mode and user mode fun, The differenc...

The difference between kernel mode and user mode gives a rudimentary form of security in the following manner. Convinced instructions could be executed only when the CPU is in kern

Hypertext transfer protocol (http), It's a common protocol or "language" co...

It's a common protocol or "language" computers use to "speak" to each other over the Web.

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.

Global positioning system, How does GPS work in the field of Sport or athle...

How does GPS work in the field of Sport or athletics?

Database, how does one create a database in mysql

how does one create a database in mysql

Explain the raster scan display system, Question 1 Explain boundary fill a...

Question 1 Explain boundary fill and flood fill polygon filling algorithm Question 2 Draw and explain the block diagram of typical workstation Question 3 Explain the ras

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