I managed to boot linux normaly with lilo on A7n8x-x with sil 3112 sata controler using gentoo linux with kernel 2.6.5 but not without problems at first. So here is the story
I booted from the linux cd ... my sata was detected as hde - notice that.
Installed all the stuf , compiled the kernel with no ATA suport for Sil because that driver is for pci ata raid cards and works for some sata controler but real bad. In SCSI section at LOW LEVEL DRIVER there is SATA section .where you can find the sil driver.
Copy lilo .. when i tried to install it .. it gave me this error Fatat: raid_setup("stat(/dev/hde") and tainted the mbr.
So i booted with the Linux cd but with my new root file system " some_kernel root=/dev/hde3 noinitrd ro" (some_kernel is the image you have on the cd with sil suport ..
Aftet that i managed to install lilo.
Choose linux .... and i got a kernel panic. unable to mount root file system.
i select the label linux (wich was my new kernel compiled with real sil 3112 suport)
my_kernel root=/dev/sda3 noinitrd ro
i updated /etc/fstab acordgly from hde to sda
i updated /etc/lilo.conf from hde to hda
install lilo again ( /sbin/lilo)
and boot normaly
I do not know to use grub
it is a little bit complicated for me but i think you can make a similar trick with grub. The problem is that ATA section driver for sil controler wich should be removed
from the kernel i gave me a 2 weeks headache. Or someone to write there "Iou dude .... don't try this at home"