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 ?

Unix, How do I change file permissions? Every time I execute chmod commands...

How do I change file permissions? Every time I execute chmod commands it tells me permission denied.

Write down dijkstra''s algorithm, QUESTION (a) Write down the Update ...

QUESTION (a) Write down the Update Step in the Dijkstra's algorithm explaining its complexity. (b) Propose a Generic Algorithm for Depth-First Search Algorithm, assuming

Internal storage, Internal Storage: Internal storage is also known as ...

Internal Storage: Internal storage is also known as main, primary, or (for historical reasons) core storage, or, memory. It is used to hold those instructions and data require

Library function, Library function :   These are the functions supplied...

Library function :   These are the functions supplied with the programming language. The code or definition of library functions does not have to be written in a user program w

Explain the different methods of encryption technique, Problem When a d...

Problem When a data is sent across the network it is encrypted and arranged in a way that even if there is a diversion in the flow of data should not leak the data. At the rece

Configuration of a pc, Configuration of a PC: Generally, when you thin...

Configuration of a PC: Generally, when you think of purchasing a Computer, you first try to exactly know what will be the hardware components such as processor, memory etc. of

Flowcharting, Flowcharting: Flowcharting: A Flowchart is a graphical r...

Flowcharting: Flowcharting: A Flowchart is a graphical representation of an algorithm. It can be compared to the blueprint of a building. Just as a building contractor refers

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