opt file processing

[Warner Losh]

[[ Moved to arch@ ]]


> On Jan 21, 2015, at 3:15 PM, John-Mark Gurney <jmg at funkthat.com> wrote:
> 
> Adrian Chadd wrote this message on Fri, Jan 16, 2015 at 10:43 -0800:
>> When I've done what you're doing, I end up having these options in my
>> minimal config file so opt_xxx.h is correctly populated. That way when
>> I point SYSDIR (or whichever variable it is) at the configured kernel
>> directory with the opt_xxx.h files, it all works out correctly.
>> 
>> (I still think we shouldn't be relying on "defaults", but should ship
>> the opt_xxx.h files or something to derive the opt_xxx.h and makefile
>> config bits so things like external module building is possible
>> against a kernel. Or, we just kill all module options that change
>> behaviour/ABI of things in an incompatible way.)
> 
> I have the commands that are able to stash the opt files in a kernel
> section, and then be able to extract them again so that when you build
> a kernel module it will use the correct options to match the kernel..
> 
> This is most useful for things like PAE which have a big impact...

I have patches in review that I need to revise that allow the modules’
Makefiles to know all the opts and select to include or exclude files
based on that.

Warner