Boot halts on Thinkpad X220 (Sandy Bridge)

Hello everybody,

on a Thinkpad X220 (Sandy Bridge/Cougar Point based) the installation
medium loads but halts during boot. I tested the following versions of
FreeBSD

* 8.2-RELEASE
* 9-CURRENT (latest official snapshot from 02/2011)
* 9-CURRENT (latest snapshot from Nathan Whitehorn as of 20/04/2011 [1])
* 9-CURRENT (own release medium as of today prepared with the
generate-release script)

With 8.2, I see the same error messages as [2] with PCBSD-8 (not
surprising, of course, but please note that there is no Firewire in this
notebook). I do not see what the error message is with 9.0 before it
halts. Anyway, according to Kris Moore this is a "known issue with
FreeBSD". I have not found anything about such problem in the mailing
list archives (apologies if I am wrong).

Therefore my question simply is, whether this problem is known and (if
yes) there is a fix or workaround available for CURRENT.

If needed, I can post a dmesg of a successful boot of the
openSUSE-11.4-LiveCD as reference (not doing so now because I assume the
list will anyway eat the attachment). Also, I can provide whatever can
be obtained using said Linux.

Thanks a lot or any replies! :-)

Johannes Dieterich

[1] http://people.freebsd.org/~nwhitehorn/
[2] http://forums.pcbsd.org/showthread.php?p=87366