I have the following questions wrt kernel compilation.

1. How to know whether a particular /usr/src/linux/*.c is built into the kernel or is compiled as a module?

2. If a code is built into the kernel then after I make changes to the .c file what are the compilation steps to be followed ?

3.If a code is built as module then after I make changes to the .c file what are the compilation steps to be followed ?

4.How do debug a kernel-code ie how to trace a .c file present in /usr/src/linux/ or to be more clear how to which function calls which function,what are the values of the variabels,what is the value returned ?

Hello,

1> i've experience with "make xconfig". When u run this a graphical screen/picture appears. By loading the ".config" file you can check what were built-in's and what were modules only.

2> if something was built-in or you are making some thing to be built in, you will have to compile the whole kernel.

3> if making something as modules only, then only compilation and installation of modules is required.
#make modules
#make modules_install
read this

4> i don't know.

Step by Step procedure of compiling whole kernel.

Newbie guide to compiling kernel--by DrOzz

regards