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 ?

OPERATING SYSTEM, WHAT IS MULTIPLE CONTIGUOUS VARIABLE PARTITIONING

WHAT IS MULTIPLE CONTIGUOUS VARIABLE PARTITIONING

Command processor and user interface, Command Processor and User Interface:...

Command Processor and User Interface: To the user, the most important and visible services provided by the OS is the user interface and the capabilities that it provides to ex

Obtain the truth table and a boolean expression, Problem 1. Convert the...

Problem 1. Convert the following number system 12.34 (8) to binary number system 23BC.0A (16) to decimal number system 456.012 (16) to Octal number system 123

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.

C, Byteland county is very famous for luminous jewels. Luminous jewels are ...

Byteland county is very famous for luminous jewels. Luminous jewels are used in making beautiful necklaces. A necklace consists of various luminous jewels of particular colour. Nec

Cp, I NEED FLOW CHART ANT DRAWINGS OF BASIC OPERATIONS OF COMPUTER

I NEED FLOW CHART ANT DRAWINGS OF BASIC OPERATIONS OF COMPUTER

Inforamtion infrastructure and services, benefit a company derive from mana...

benefit a company derive from managing it own information technology

Hacking, how can i hack a server

how can i hack a server

Coaxial cables, Coaxial Cables: Another metallic transmission medium w...

Coaxial Cables: Another metallic transmission medium which offers a large bandwidth, is the coaxial cable. Such cables consist of an outer protective shell made of copper tube

Elements of cpu, ELEMENTS OF CPU: The CPU is a complex IC chip having ...

ELEMENTS OF CPU: The CPU is a complex IC chip having millions of transistors. As mentioned earlier, a CPU has three major identifiable parts: Control Unit (CU), Arithmetic & l

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