Re: side-effect when enabling CONFIG_MODULES

From: Arnd Bergmann
Date: Mon Jul 18 2016 - 07:51:16 EST

On Monday, July 18, 2016 12:44:45 PM CEST Arend Van Spriel wrote:
> A question for whoever can provide the answer. I have a kernel defconfig
> with everything built-in. However, I want to compile a driver module
> against it for testing. So I enabled CONFING_MODULES, but as a
> side-effect several implicitly selected config options changed from
> CONFIG_FOO=y to CONFIG_FOO=m giving me slightly different kernel at
> least when looking at the vmlinux. So I just did sed -i 's/=m/=y/'
> .config, but I was wondering if that step can be avoided somehow?

It sounds like the options that are left out in the defconfig file
default to =m, which becomes =y if CONFIG_MODULES is not set.

make my_defconfig
echo "CONFIG_MODULES=y" >> .config
make oldconfig
make savedefconfig
cp defconfig arch/*/config/my_defconfig