Programatically modifying .config

Programatically modifying .config

[Drew DeVault]

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?

--
 Drew DeVault

Re: Programatically modifying .config

[Pavel Machek]

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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).
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: Programatically modifying .config

[Randy Dunlap]

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.)


-- 
~Randy

Re: Programatically modifying .config

[Steven Rostedt]

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