From: eLinux.org
How to use a new kernel with the emulator or on a product.
In general, this will be very product-specific.
On the ADP1, you can boot using a specific kernel using fastboot, which will send it to the board as part of the bootup sequence. Specify the kernel as one of the parameters to the 'fastboot boot' option. See http://www.gotontheinter.net/content/fastboot-cheat-sheet for details.
You can create a "boot" image directly, and install that to the boot or recovery flash partition manually. This can be done either using a running kernel or using fastboot.
See these instructions for doing that: http://android-dls.com/wiki/index.php?title=HOWTO:-Unpack,-Edit,-and-Re-Pack-Boot-Images
Also, you can install the kernel into a recovery image, and install the recovery image using the system recovery procedure.
You can specify the kernel to use with the emulator using the '-kernel' command line option.
There are some interesting notes about using the emulator without specifying a AVD file at: http://groups.google.com/group/android-platform/browse-thread/thread/59-0fde1e9865a
For an OMAP EVM, using the Android image available from Mistral, place a new uImage on the SDCARD at the root the vfat partition. The bootloader will run the commands (from where??) to load the uImage and boot it-
Note that for the OMAP EVM, you need to have the board configured to boot from sdcard, rather than from flash.