I'm glad someone else is struggling with it. I thought I was a guru until I started messing with Linux. I'm using Mandrake, and Gnome (I know, boo hiss...). I have an old legacy aureal card that I had to set up manually. When I finally got done, I know SO MUCH MORE. Anyway, I thought I would make a "batch" file to make installation easier for others, but I'm still not completely sure on how to do that. Anyway, here's your explanation...
Make sure you know EXACTLY what chipset you've got. It won't mess anything up (not sure...) but it creates a mess with folders and such that just take up space and make this disorganized (I'm anal).
1. Download kernel-source-2.4.8-26mdk.i586.rpm
Download this from sourceforge.net or something. It's not all that hard to find.
2. Find the .rpm file and run the following command.
rpm -ivh --nodeps kernel-source-2.4.8-26mdk.i586.rpm
Remember the --nodeps parameter or it will complain. Basically, it's looking for a dependency that it isn't really dependent on. Go figure.
3. Untar and unzip the tar.gz file you downloaded with the drivers.
I'm assuming you've already done this since you're getting the error on the make command.
4. Type the following commands. Make sure you're root if you haven't had to change already.
ln -s /usr/bin/lspci /sbin/lspci
mv /ust/include/linux /usr/include/linux-2.4.8mdk
ln -s /usr/src/linux-2.4.8/include/linux
5. Go to the directory with the driver files. Coming to the end now.
make install au88X0
Command is dependent on your chipset. X0 is the chipset, either 10, 20, or 30. You get the idea.
6. Depending on your distribution (most likely you won't have to with Mandrake 8.1, I didn't have to), you MAY have to go into your /lib/modules and navigate around until you find the kernel and then the sound drivers. Once in there, type the following command.
modprobe au88X0
Once again X0 related to the chipset.
7. Fire up XMMS and let 'er rip. Any questions, let me know.