Kconfig useful rules

make config
make menuconfig
Asks questions your should reply to

make defconfig   (*_defconfig)
Apply a predefined configuration

make oldconfig
Applies current .config, asking only unanswered questions


More options, not in the current code base:
make randconfig
Randomize, to build-test in a loop
make allyesconfig
All yes, where possible
make allnoconfig
All no, where possible