kernel panic on boot - ServerWorks CSB6

[Norberto Meijome]

Hi all,
I am trying to install 5.4 on a box that's been running Linux. It's a 2 
year old 'Snap Appliance 4500' ( 
http://www.snapappliance.com/page.cfm?name=4500Main&nav=4500 ), with 4 x 
120 GB EIDE, P4, 512 Mb.

As soon as I try to load the kernel I get :
--- (copied by hand )
Fatal trap 10: trace trap while in vm86 mode
instruction pointer = 0xf000:0xf842
stack pointer        = 0x0:0xff8
frame pointer       = 0x0:0x0
code segment      = base 0x330026, limit 0x1, type 0x9
                           = DPL 3, pres 1 def32 0, fram 0
processor eflags  = interrupt enabled, vm86, IOPL=0
current process   = 0 ()
trap number        = 10
panic : trace trap
uptime : 1 s
-------------

Every time, the same pointers / segments. This happens right after the 
kernel memory addresses (data? segment? pls excuse my ignorance) show 
after pressing an option in the boot menu.
I've been trying to install from a USB external CD ROM, with 5.4 release 
cd, iso, root at harlow.cse.buffalo.edu, Sun May 8 05:59:07 UTC 2005 (date 
showing from bootloader).

- The same happens if I chose safe mode
- The same happens if I disable dma from the boot loader prompt

- I took one of the HDs out, installed in another pc, installed again as 
drive #1, same problem and panic.

- I tried with only that one harddrive with FBSD 5.4 installed (all 
other HDs removed) - same panic
- I tried with no HDs, just to see if the cd would boot - same panic.

- I tried with 4.9 release CD, ISO from Monday oct 27 , 2003, same 
problem, slightly different addresses in panic (as expected, though 
quite similar):
---
Fatal trap 10: trace trap while in vm86 mode
instruction pointer = 0xf000: 0xf842
stack pointer = 0x0:0xff8
frame pointer = 0x0:0x0
code segment = base 0x0, limit 0x0, type 0x0
                     = DPL 0, pres 0, def32 0, gran 0
processor flags = interrupt enabled, vm86, IOPL=0
current process = idle
interrupt mask = net tty bio cam
trap number = 10
panic = trace trap
uptime = 0 s
-----

- booting with Linux Gentoo 5.0 universal cd works fine
- booting with knoppix 3.8 works just fine. With this, I got some 
hardware info:

lspci:
---
0000:00:00.0 Host bridge: ServerWorks GCNB-LE Host Bridge (rev 32)
0000:00:00.1 Host bridge: ServerWorks GCNB-LE Host Bridge
0000:00:04.0 VGA compatible controller: ATI Technologies Inc Rage XL 
(rev 27)
0000:00:05.0 IDE interface: Silicon Image, Inc. (formerly CMD Technology 
Inc) PCI0680 Ultra ATA-133 Host Controller (rev 02)
0000:00:0f.0 ISA bridge: ServerWorks CSB6 South Bridge (rev a0)
0000:00:0f.1 IDE interface: ServerWorks CSB6 RAID/IDE Controller (rev a0)
0000:00:0f.2 USB Controller: ServerWorks CSB6 OHCI USB Controller (rev 05)
0000:00:0f.3 Host bridge: ServerWorks GCLE-2 Host Bridge
0000:00:10.0 Host bridge: ServerWorks CIOB-E I/O Bridge with Gigabit 
Ethernet (rev 12)
0000:00:10.2 Host bridge: ServerWorks CIOB-E I/O Bridge with Gigabit 
Ethernet (rev 12)
0000:02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5704 
Gigabit Ethernet (rev 02)
0000:02:00.1 Ethernet controller: Broadcom Corporation NetXtreme BCM5704 
Gigabit Ethernet (rev 02)
-----

lspci -v : attached
dmesg (linux knoppix 3.8): attached

I'd appreaciate any pointers / suggestions / help.

thanks in advance,
Beto