Usage of "files" for config

[Srinivas]

Eygene, Your reply is very helpful. Thank you very much.

On Tue, Oct 28, 2008 at 1:16 PM, Eygene Ryabinkin <rea-fbsd at codelabs.ru> wrote:
>> I would like to know the usage of files and files.[arch] in sys/conf.
>> Basically, I didnt get the advantage of having a common file for
>> compilation(like files) rather than an individual Makefile in each
>> subdirectory.
>
> 'files' and 'files.$ARCH' are the input directives for the config(8)
> utility.  Makefile is produced with the help of these files.  The
> rationale for having 'files' and 'files.$ARCH' is simple: there are
> platform-specific directives and common directives.

Still, I didnt get the purpose of having a common "files" file for the
kernel to generate Makefile.

I am trying to understand the advantage of this approach with the
conventional way of having a makefile for each sub-directory(device or
module) and recurse from top of kernel with a configuration file
dictating what features need to be included in the kernel.

Thanks,
Srinivas