How to add a config parameter into the kernel

[Emre Can Sezer]

Hi,

I'm trying to modify the kernel and as I do so I realize that a compile
time option would be best to include or exclude my modifications.  I want
to add a config option that would set a macro such as CONFIG_ECS.  Which I
can then use to replace some functions or add functionality to existing
ones.

I'm using Hardy, on a x86-64.  I tried adding the line CONFIG_ECS=y into
the .config file in <source-dir>/debian/config/amd64 but when I run the
script that validates the various config files
(<source-dir>/debian/scripts/misc/oldconfig amd64), it complains about the
entry and removes it.

How can I add my own config option so I can use #ifdef CONFIG_ECS?

I'm not sure if it's relevant, but I'm using the compilation technique
provided in https://help.ubuntu.com/community/Kernel/Compile using
fakeroot.

Thanks in advance

John