The onboard Intel AC'97 codec is supported by the snd-intel8x0 alsa driver. I've found that it's important that this is compiled as a module, rather than within the kernel statically.
Under the kernel configurator, it is listed under device drivers -- sound --
alsa -- pci devices -- Intel/SiS/nVidia/AMD/ALi AC97 Controller. Enable this a module.
After you build and boot the kernel, you should be able to run
and have it automatically set your card up. NOTE: On this particular laptop,
the sound is a little quirky. You'll need to adjust settings with
and turn ON or OFF the "External Amplifier" channel. I would suggest playing a
sound sample with mpg123 or xmms while you are playing with the settings to tune it to