Hi!
I have the same motherboard - and the same problem here.
Things I've tried so far:
- Installing FreeBSD 7.0, 7.1, 7.2 and 8.0RC3: same problem.
- Installing FreeBSD 6.x (even 6.9): works fine
I didn't try installing 6.x and updating, because I red on some foruns that the problem will get back as soon as I update the system.
By "same problem" above, I mean:
- Booting with ACPI enabled: at the very beggining of boot messages (sortly after the processor's detais), the kernel starts showing a message (something about ACPI. It scrolls to fast to read) over and over - until it stops with "kernel panic" and some random flashing characters.
- Booting with ACPI disabled: it boots up, but hangs on "Trying to mount root from ufs:/dev/md0". If I turn verbose boot on, I can see it actualy goes a bit futher and tryies to run "sysinstall".
I also tried to make a custom boot CD, with a custom kernel, removing support to all unnecessary devices (USB, parallel, serial, firewire, scsi, raid, etc), and with root at the CD itself. It boots and drops on the "choose root filesystem to mount" prompt (this was intentional), but, when I try the "?" command to list root devices candidates, I get an empty list.
Scrolling the boot messages up a little, I could see what I think is the root of the issue: lots of messages like "unable to map interrupt", "unable to allocate interrupt", etc - about all devices. It detects my ATA and SATA controllers, but shows this message and does not detects any of devices (HDs, CDs) attached to them.
Today, I finally updated my motherboard's BIOS to the last version available at DFI's site. After that, I spend a morning playing with setup's parameters. I've even tried to allocate IRQs manually at setup, but the problems is always the same.
So far, I see no mean to make this board work with FreeBSD

( I think FreeBSD doesn't like this board's ACPI controller - but, without ACPI support, FreeBSD is unable to talk with this board about resurces (read "IRQ") allocation.
Does somebody have any clue?
I was also wondering... what may have changed from 6.x to 7.x kernel's to cause this problem?
Thanks in advice!
Rudolph