learn,how to mix C and Assembly Language ?, Basic Computer Science

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 ?

Arithmetic and control unit, micro routine

micro routine

Operating system, Operating system: An operating system is system sof...

Operating system: An operating system is system software which may be viewed as an organized collection of software consisting of procedures for operating a computer and pro

System software, SYSTEMS SOFTWARE Systems Software generally is ...

SYSTEMS SOFTWARE Systems Software generally is the software which control the computers and other peripherals. Ex: MS DOS, Windows 95, Unix, NetWare and Windows NT et

Foundation of computer system, Foundation of Computer System Q.No-1: W...

Foundation of Computer System Q.No-1: What do you understand by the Efficiency in term of Computers? and How will you measure it? Also define Speed and its factors which ca

Ip basics, IP provide connectionless service to upper layer IP protocol is ...

IP provide connectionless service to upper layer IP protocol is very simple could not guarantee the reliability of transportations IP protocol is Point to Point IP provide the unif

COMputer fundamentals, explain the expression "A=5"

explain the expression "A=5"

Cmis, how much it cost for 8 week class

how much it cost for 8 week class

Operating system, Does Process Manager in Operating System know the depende...

Does Process Manager in Operating System know the dependency order that Process A depends on Process B?

Explain the functions of alu, Question 1 Write down the Booth's Multiplica...

Question 1 Write down the Booth's Multiplication Algorithm. Justify the Booth's Multiplication Algorithm Question 2 Explain the functions of ALU Question 3 Define the term ins

Perform a mail merge to send invitation, Question Elaborate the various...

Question Elaborate the various steps in performing a Mail Merge. Perform one mail merge operation for sending invitation for a conference which is being conducted in your organ

Write Your Message!

Name

Email id

Message

Verfication Code

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!

Submit Assignment

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd