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 ?

Features of python, • Easy-to-learn: Python has comparatively few keywords,...

• Easy-to-learn: Python has comparatively few keywords, easy structure, and a clearly distinct syntax. This permits the student to pick up the language in a comparatively short per

System software, System software: System software helps run the  compu...

System software: System software helps run the  computer hardware and system. It is designed to control the operations of a computer and coordinate all external devices like c

Mainframe architecture, Mainframe Architecture: Till a few decades bac...

Mainframe Architecture: Till a few decades back, all computing was controlled through the central mainframes server. Multiple users could connect to the central host through u

Explain digital multiplexers, Problem 1 Perform the following conversio...

Problem 1 Perform the following conversion a. (ABE) 16 =() 2 b. (101011) 2 =() 10 2 Explain how full adder adds three bits 3 Explain digital multiplexers

Briefly explain the stage and the timeline, Question 1 Briefly explain the...

Question 1 Briefly explain the Stage and the Timeline Question 2 What is Device Central? How it is useful for previewing mobile content? Question 3 Which are the f

Embedded system, what question can be asked for embedded system

what question can be asked for embedded system

Knowledge of the environment of ai system, Knowledge of the Environment ...

Knowledge of the Environment We must distinguish between knowledge an agent receives through it's sensors and knowledge about the world from which the input comes. Knowledge a

Convert string to super ascii, A string S is said to be "Super ASCII", if i...

A string S is said to be "Super ASCII", if it contains the character frequency equal to their ascii values. String will contain only lower case alphabets (''''''''a''''''''-'''''''

SG Fuel power supply, Where can I find power supply HIPRO HP-W460GC33 for S...

Where can I find power supply HIPRO HP-W460GC33 for Silicon Graphics Fuel computer

Analog transmission, Analog Transmission: In analog transmission, ther...

Analog Transmission: In analog transmission, there is a continuous up and down pattern. For example, one wave constitutes one cycle, which is measured in the unit called Hertz

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