Re: Programatically modifying .config

Steven Rostedt
2017-05-17T02:43:05Z

On Tue, 16 May 2017 17:31:17 -0700
Randy Dunlap <rdunlap@infradead.org> wrote:

> On 05/16/17 03:57, Pavel Machek wrote:
> > On Sun 2017-03-12 16:38:02, Drew DeVault wrote:
> >> I'm in the research stage of making it so something to the effect of
> >> `make setconfig OPTION="CONFIG_E100E=y"` will work, bringing it up here
> >> for some discussion first.
> >>
> >> Digging into the kconfig code, this seems feasible, but complicated. A
> >> simple solver of some sort will be necessary to make the Depends expr
> >> true, and this tool would also have to hit up the Selects and Implies
> >> lines.
> >>
> >> I expect there will be edge cases that this tool can't cope with, and
> >> I'm okay with just letting that be the case.
> >>
> >> Any thoughts?
> >
> > You can prepend (or append?) desired config option to .config, then
> > run make oldconfig. And yes, script for automatically modifying
> > .config would be nice... as would be script to automatically do
> > "configuration bisect" (because some bugs are config dependend and
> > nasty).
>
>
> tools/testing/ktest/ktest.pl has some support for config bisecting.
> (I have not tried it.)
>
>

ktest.pl works great if you have it set up, but can be difficult if you
just want to do a bisect without having ktest already established. I
created a standalone config-bisect.pl that just does the bisecting.
It's still in beta form.

I just pushed it up to my branch. You can try it out here:

git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest.git

Check out the branch called: config-bisect

The file is in tools/testing/ktest/config-bisect.pl

The comments at the beginning of the file should explain how to use it.
Try it out. You can be my first tester :-) I've used it only once, but
haven't had time to push it out to Linus.

-- Steve