I have isolated the line where the kernel hangs.

The dmesg ends at:
boot device: xe0
root on xe0
mountroot: trying nfs...
nfs_boot: trying DHCP/BOOTP

You can not break into ddb via NMI when it hangs.

The last call is makes is the following:

src/sys/nfs/nfs_boot.c:280

        error = ifioctl(so, SIOCAIFADDR, (caddr_t)&iareq, procp);

On 1.6.2 the nfs_boot line is followed by:
       in6_ifattach: xe0 is not multicast capable, IPv6 not enabled

Will keep digging, just wanted to submit what I have found so far.



-Ober