problem booting FreeBSD 8-Beta4 on Soekris net5501

[Graham Menhennitt]

G'day,

I'm upgrading a Soekris net5501 from FreeBSD 7-Stable to 8-Beta4 (via
source). I've done a buildworld, buildkernel, and installkernel. When I
try to boot the new kernel, it stops very early on in the boot sequence.
The serial console shows:

/boot/kernel/kernel text=0x32f9f0 data=0x36374+0x1e580
syms=[0x4+0x40720+0x4+0x592a3]                                                                                                                

-                                                                                                                                                                                              

Hit [Enter] to boot immediately, or any other key for command
prompt.                                                                                                                          

Booting
[/boot/kernel/kernel]...                                                                                                                                                               

/

The slash at the end is the first character of the spinner as it's
loading the kernel. It never shows the second character. I've tried two
different kernel configs - my own (from 7 modified to build with 8) and
aragon's from
http://www.nabble.com/no-time-of-day-clock-registered-on-net5501,-FreeBSD-8-td24544248.html
(with the line "options STOP_NMI" removed to get it to build). They both
do the same thing.

My loader.conf is the same as in 7:

beastie_disable="YES"
comconsole_speed="19200"
console="comconsole"

My kernel config is below.

Does anybody have any clues please?

Thanks for any help,
  Graham

cpu            
I586_CPU                                                                                                                                       

ident          
maxwell                                                                                                                                        


options         CPU_GEODE
options         CPU_SOEKRIS


options         SCHED_ULE               # ULE scheduler
options         INET                    # InterNETworking
options         INET6                   # IPv6 communications protocols
options         SCTP                    # Stream Control Transmission
Protocol
options         FFS                     # Berkeley Fast Filesystem
options         SOFTUPDATES             # Enable FFS soft updates support
options         NFSCLIENT               # Network Filesystem Client
options         NFSSERVER               # Network Filesystem Server
options         PROCFS                  # Process filesystem (requires
PSEUDOFS)
options         PSEUDOFS                # Pseudo-filesystem framework
options         COMPAT_FREEBSD7         # Compatible with FreeBSD7
options         SYSVSHM                 # SYSV-style shared memory
options         SYSVMSG                 # SYSV-style message queues
options         SYSVSEM                 # SYSV-style semaphores
options         _KPOSIX_PRIORITY_SCHEDULING # Posix P1003_1B real-time
extensions
options         IPFIREWALL
options         IPFIREWALL_VERBOSE
options         IPDIVERT
options         IPFIREWALL_NAT          # ipfw kernel nat support
options         LIBALIAS

device          pci

device          ata
device          atadisk         # ATA disk drives
options         ATA_STATIC_ID   # Static device numbering

device          scbus           # SCSI bus (required for SCSI)
device          da              # Direct Access (disks)
device          uart            # Generic UART driver

device          miibus          # MII bus support
device          vr              # VIA Rhine, Rhine II

device          wlan            # 802.11 support
device          wlan_ccmp       # 802.11 CCMP support
device          wlan_tkip       # 802.11 TKIP support
device          ath             # Atheros pci/cardbus NIC's
device          ath_hal         # pci/cardbus chip support
options         AH_SUPPORT_AR5416       # enable AR5416 tx/rx descriptors
device          ath_rate_sample # SampleRate tx rate control for ath
device          loop            # Network loopback
device          random          # Entropy device
device          ether           # Ethernet support
device          tap             # Ethernet tunnel.
device          tun             # Packet tunnel.
device          pty             # BSD-style compatibility pseudo ttys
device          md              # Memory "disks"
device          gif             # IPv6 and IPv4 tunneling
device          bpf             # Berkeley packet filter
device          uhci            # UHCI PCI->USB interface
device          ohci            # OHCI PCI->USB interface
device          ehci            # EHCI PCI->USB interface (USB 2.0)
device          usb             # USB Bus (required)
device          ulpt            # Printer
device          umass           # Disks/Mass storage - Requires scbus and da