[OSSNA] Intro to kernel hacking tutorial

[Anatoly Pugachev]

On Mon, Sep 2, 2019 at 5:09 PM Valdis Klētnieks <valdis.kletnieks at vt.edu> wrote:
>
> On Mon, 02 Sep 2019 15:42:19 +0300, Anatoly Pugachev said:
>
> > is it intentionally that you use
> >
> > yes "" | make oldconfig
> >
> > instead of
> >
> > make olddefconfig
>
> They do something different.  'olddefconfig' just takes the platform or
> architecture defconfig and updates it for any new CONFIG_* variables added
> since the last time the defconfig was updated in the tree.
>
> yes "" | make oldconfig  does the same updating for new CONFIG_* variables, but
> starts with the most recent .config - which produces wildly different results
> if the .config had previously been minimized by 'make localmodconfig' or other
> similar techniques.

Maybe i don't understand something, but someone would probably want to
patch kernel 'make help' accordingly , since current one lists:

$ make help
  oldconfig       - Update current config utilising a provided .config as base
  olddefconfig    - Same as oldconfig but sets new symbols to their
                    default value without prompting

Thanks.