Xilinx-linux-audio application

Hi,
Iam trying to run linphonec(open source linux based IP Phone software)
in xilinx-development board. I'd cross compiled linphone in
powerpc-405-linux platform. Now I could run the same, in board. But the
problem is, I dont have the ac97 (Audio codec linux BSP)
driver/adapter. Also I've some general purpose AC97 files (as97.c &
ac97.h) under linux (montavista linux_2.4_devel) distributions. Now
there are two sound systems ALSA&OSS in linux.  Linphone supports both
ALSA & OSS. Then does it mean either one I can select and accordingly,
should I've to develop the driver for my xilinx board.
BTW, Whats the difference b/w adapter & driver. How can I modify
general purpose driver to BSP.
could anyone clarify me,
Prakash