HOW TO REBUILT THE ANDROID EMULATOR-SPECIFIC KERNEL:
====================================================

You need to have the Android toolchain in your path
(i.e. 'arm-eabi-gcc --version' must work)

then:

git clone git://android.git.kernel.org/kernel/common.git kernel-common
cd kernel-common
git checkout origin/android-goldfish-2.6.27

export CROSS_COMPILE=arm-eabi-
export ARCH=arm
export SUBARCH=arm
make goldfish_defconfig    # configure the kernel
make -j2                   # build it

=> this generates a file named arch/arm/boot/zImage

Now, you can use it with:

  emulator -kernel path/to/your/new/zImage <other-options>

Voila !