I Payed Rs.45000 to understand that my dear friend.

Anyway have you heard of JVM- Java virtual machine ?

RTOS is Like a JVM for an embedded engineer.

Suppose you have been assigned to write a code for an application based on x86 platform today since targets boards are cheap.

A year later you are assigned to port the code to say a TI MSP430 ..

You will be dead..by the time the product rolls out.

Here's where a RTOS come into picture.

You write your code say in C which runs on the RTOS u are using.

Remember C source code is portable not the executables so you can't surely take executables from x86 to MSP

so you recompile your RTOS say( I have learn't Vxworks)Vxworks
for msp430

I take my source and put it into this project , I may need to make small changes but not much.

So I can roll out my products faster. memory managment,hardware bus managments... all the hardware is taken care by rtos you don't need to sweat learning all processors.

For a company if it can get faster output it's the best thing.
Also the skill level of employees required isn't too much since indepth hardware knowledge isn't that important.

All said and done , a c code or a hex is much smaller more efficient and also a good hardware knowledge is what makes the difference between a program and a very good program.

the costs of putting large storage spaces may be prohibitive for RTOS usage , hence you could do it in hex /c

Also one important point a GPOS like Windows has no user definable premetive scheduling mechanism for tasks, whereas a ROS had this feature

Hope this will help you.I don't care if it's your home work.
But if you intend to use Rtlinux I want to learn using it too.

Bye
Deepak

I am putting down an example form my vxworks course
#include<vxworks.h>
#include<iolib.h>
#include<selectlib.h>

int fd;

void t1()
{
char nm[30];
write(fd,"HELLO",6);
read(fd,nm,30);

printf("%s",nm);

close(fd);


}





void root_sel()
{

pipeDevCreate("TEST PIPE",10,100);

fd = open("TEST PIPE",O_RDWR,NULL);

taskSpawn("TEST',23,NULL,1000,t1,0,0,0,0,0,0,0,0,0,0,0);



}

chis coe is creating a pipe device and the spawning/forking a task,The task writes and reads the pipe using the file dispcriptor obtained during spawning process