Linux compilation guide

# Clean, fetch, configure, and compile in poky/yocto
rebake virtual/kernel
or
bitbake -fc virtual/kernel

# Failure : .. is not clean, please run 'make mrproper'
# Failure : .config is missing.  Please run 'make oldconfig', or 'make menuconfig'
! Checking Makefile you can see this error occurs when .config is missing or include/config/ exists.
ls -l include/config/                     #very likely empty
rm -fr include/config/


# Build Linux kernel only for Android

(rm -fr out/..../kernel/...)
make -j bootimage