Yocto Labs starts to explain how to change the kernel config in "10 Customizing Linux Kernel":
$ bitbake virtual/kernel -c menuconfig
After that I can run:
$ bitbake virtual/kernel -c clean
$ bitbake virtual/kernel
$ bitbake core-image-minimal
It does a little work - two task are rerun.
After updating the SD-card the kernel version doesn't change. Its still "Linux microzed 3.8.11-xilinx #1 SMP PREEMPT Thu Nov 20 14:04:14 GMT 2014 ...". Looking at the kernel date it hasn't recompiled.
Can anyone help?