Scripting the kernel configuration.

[Cheesyjuggler64]

I've been trying to understand how interact with the kconfig system that the Linux kernel operates on to script it and I've got no idea how. Is there anyway to programmatically traverse the kconfig structure like menu config does but instead save it is some sort of custom data structure or do you have to individually read the kconfig and set up the structure yourself. Is there no way to hook into some preexisting configuration scripts which all ready have to read all this data like make menuconfig and work from there?

[zen_desu]

I'd like to be wrong, but I think you have to read the kconfig files in each dir and handle the includes in them.

that being said, you could use the parser from an existing script, and i think there are libraries for this.
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µgRD dev
Wiki writer

[Cheesyjuggler64]

So if I were to try and build one is the best way to just read in all the kconfig files and assimilate a structure from there?

[Cheesyjuggler64]

After doing some research, it says that there already exists an inbuilt parser for kconfig files. https://github.com/paulgazz/kmax/blob/master/kextractors/kextractor-4.12.8/README.md But I have no idea how to use it/ get its output. If anyone more experienced with this sort of thing could give me heads up that'd be great.

Moderator note: Fixed the url format. -- Banana

[Goverp]

Cheesyjuggler,

If you're into python, you might like https://pypi.org/project/kconfiglib/.

My experience writing an awk parser for Kconfig files is that their syntax is pretty horrible - basically an agglomeration of ad-hoc rules, resulting in such horrors as parsing producing different results depending on tab settings. Also, there are a heck of a lot of them in the kernel tree, not all of which will be relevant to any particular enquiry.

Net of that is, if someone's already gone through the pain and written a parser, then use it, don't reinvent the wheel!
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Greybeard

[zen_desu]

[sublogic]

For the adventurous, Kconfig is documented in the source tree's Documentation/kbuild subdirectory.

There is even a yacc grammar in scripts/kconfig/, if you can grok the yacc.

Finally, there is a self-contained script, scripts/kconfig/streamline_config.pl , that parses all the Kconfig files and the Makefiles. You could use it as a template of sorts, except that 1) it is written in perl, a language that looks like shell, awk and sed thrown into a blender with some gravel, and 2) perl scripts look like text files that passed through a communication channel with a large bit error rate. On the plus side, if you know awk, sed and shell, you almost know perl ! Start with man perlintro .

Have fun. Or be wise.

(To be fair, perl is pretty cool once you get the hang of it. IMHO It is the best glue language when it comes time to read files in a weird format and convert them to another weird format. It may be cryptic but it is also very concise, and the concision helps to focus on the task --like algebra compared to words.)