FreeBSD 8.0-RC3/amd64 cannot boot on VirtualBox

[Daniel Braniss]

> FreeBSD 8.0-RC3/amd64 cannot boot on VirtualBox.
> Boot will stop and consume 100% cpu power during boot sequence 
> as displaying as follow:
> 
>   Trying to mount rott from ufs:/dev/md0
>   warning: no time-of-day clock registered, system time will not be set accurately
> 
> checked environment:
> 
>   FreeBSD 9.0-CURRENT #44: Mon Nov 16 09:51:20 JST 2009  amd64
>   Core2 Quad Q9550
>   virtualbox-3.0.51.r22902_2
>     cpu: Core2 Quad Q9550 1-core
>     mem: 1024MB
>     VT-x: enable
>     nested paging: disable
> 
> Is there anyone can boot 8.0-RC3/amd64 on VirtualBox?

it's running ok, but with slight diffs:
	Virtualbox-3.0.51r23006
	(only mod is that I changed the boot.rom, to get pxe
         boot to work).
and the host is 8.0-PRERELEASE