https://www.baeldung.com/linux/oldconfig-target-kernel-makefile
We can automatically generate a config to build upon from various targets:
- defconfig – Generates a default config for the current architecture from predefined rules, such as arch/x86/configs/x86_64_defconfig for x86_64 systems.
- localmodconfig – Generates a config based on the current kernel’s configuration and loaded modules to disable unneeded modules.
- localyesconfig – Similar to localmodconfig but changes all module (m) options to built-in (=y).