build - How do you non-interactively turn on features in a Linux kernel .config file?

Question

I have a situation where our software needs to work with several different Linux kernel distributions / kernel trees. (including Android forks)

In trying to automate our build process, I am finding that some of the defconfig files for particular builds we need to support do not include the kernel modules we depend on.

For example, let's imagine I need an option called XXX in my .config. For some dependencies, I can do something like this:

sed -i 's/# CONFIG_XXX is not set/CONFIG_XXX=m/' .config

For others, it's not so easy since the dependency may span multiple lines of .config statements.

Is there a more supported way to do this non-interactively, or am I stuck writing a more complex search-and-replace script?

Answer 1

The kernel has a tool (./scripts/config) to change specific options on .config. Here is an example:

./scripts/config --set-val CONFIG_OPTION y

Although, it doesn't check the validity of the .config file.