To build source-based kernel:

1. Set CROSS_COMPILE to an appropriate path prefix, e.g.,

   export CROSS_COMPILE=../cm/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi-

2. Build kernel:

   make VARIANT_DEFCONFIG=jf_vzw_defconfig \
        SELINUX_DEFCONFIG=jfselinux_defconfig jf_defconfig
   make -j 4


And to merge the kernel into recovery:

3. Pull recovery partition from device:

   adb reboot recovery
   adb root
   adb shell 'dd if=/dev/block/mmcblk0p21 of=/tmp/recovery.img bs=262144'
   adb pull /tmp/recovery.img

4. Merge newly-built zImage into recovery.img:

   ../cm/out/host/linux-x86/bin/unpackbootimg -i recovery.img
   cp arch/arm/boot/zImage recovery.img-zImage

   ../cm/out/host/linux-x86/bin/mkbootimg --kernel recovery.img-zImage \
       --ramdisk recovery.img-ramdisk.gz \
       --cmdline "`cat recovery.img-cmdline`" --base 0x80200000 \
       --pagesize 2048 --ramdisk_offset 0x02000000 -o recovery.img