I changed the IDE disk from Seagate ST315323A (15.3Gb, ATA66) to Western Digital WD200 (20Gb, ATA100) and then the prefetch_abort db problem disappeared!!!
I really couldn't figure out why the disk makes the prefetch failed.
Now I could boot up the board successfully (except the ethernet is really borken.).

justind@synology.com said: 
> After properly configuring the S4D1 switches, we (Joshua and I) got correct pci intr maps now.  Thanks a lot!
> However, we still have the same db problem.
> The ethernet doesn't work even without the PCI IDE controller.
> And we run the evaluation board in Cyclone microsystems' 80300BP backplane.
> 
> -Justin
> 
> Allen Briggs <briggs@wasabisystems.com> said: 
> > On Wed, Jun 25, 2003 at 07:30:07PM +0800, Jaw-Shiang Joshua Huang wrote:
> > > The pci intr map seems wrong.
> > 
> > As Jason mentioned, this is due to the switch settings on the board.
> > Reverse all four switches on S4D1 so that they are (from top to bottom)
> > Right (off), Left, Right, Left.
> > 
> > > I want to boot NetBSD on Xscale and try to mount root on the disk
> > > because the Xscale MB seems with a bad network controller.  In
> > > Redboot prompt command, it cannot ping successfully, even ping itself.
> > 
> > Ouch.  Does the ethernet work OK without the PCI IDE controller in
> > place?  Or does it fail the same way?  What are you running the board
> > in?  A PC, or a backplane?
> > 
> > -allen
> > 
> > -- 
> >  Allen Briggs                     briggs@wasabisystems.com
> >  Wasabi Systems, Inc.             http://www.wasabisystems.com/
> > 
> 
> 
> 
> --
> Synology Inc.
> 25521814 ext 821
> justind@synology.com
> 
> 
> 



--
Synology Inc.
25521814 ext 821
justind@synology.com