actually i want to call a function which is stored in my file.I want to call the function in the source code before some kernel function. So how should i do it...

Thanks in advance..

Please elaborate.

hi,
Ask your kernel related queries on kernelnewbies mailing list. and also try to explain your problem in brief about what you want to do?

i wrote some code in one file and in that file there is one function . i want to call that function in the kernel code. i called that function in main.c , in that start_kernel(). and during compilation it is not working .
so i wanted to ask can i directly call my own written function in kernel???

i compiled the kernel with the file in which i have written the function which i want to call in main.c file of kernel.

try exporting kernel function by using EXPORT_SYMBOL(fun_name)

Please explain "it is not working".

Is there a compilation error ?
Is it crashing the kernel ?
Is it just not doing what expected ?

Can you explain what your function is for ?

well function accesses one file which contains some information written using structure.
and i want to extract the same into similar but kernel data structure.
so i am calling that function into "start_kernel" fun. of main.c (in fs )as upto there root file sys gets mounted.

when i compiled the kernel it gave errors regardin the

#include<stdio.h> , #include<stdlib.h> .....no such file or directory..
FILE *fp..... fp undeclared like that............

well one question again..
in the same function we hav used "fopen" to open the file which contains
the information.
Is that correct?
If not then what should be used to open the file?

hope so this is sufficient..
thanks for all the replies.
and waiting for the remaining ..

For obvious reasons, you cannot use any standard library call nor system calls in the kernel.

SO if i cant use the library functuions then which functions i can use to access the files on hard disk ?
Or how can i access the RDBMS databases then ?
Where can i get info about these functions?
can u show me example or if it already used in kernel then
where it is used ?

This is mostly not the kernel business. The kernel is providing applications a method to access files, but is seldom itself a client of this service.
This is definitely not the kernel business.
If you insist doing that, have a look at acct.c calling filp_open().