amd64/163092: FreeBSD 9.0-RC2 fails to boot from raid-z2 if AHCI is enabled

[Axel Gneiting]

>Number:         163092
>Category:       amd64
>Synopsis:       FreeBSD 9.0-RC2 fails to boot from raid-z2 if AHCI is enabled
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Dec 06 11:10:08 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Axel Gneiting
>Release:        9.0 RC2
>Organization:
private
>Environment:
FreeBSD nas.localdomain 9.0-RC2 FreeBSD 9.0-RC2 #0: Sat Nov 12 18:35:25 UTC 2011     root at farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64

>Description:
The bootloader just spins a bar when AHCI is enabled, but boots in IDE moed.

Mainboard: ASUS M4A78LT-M with AMD 760G chipset.

Bootloader was installed on all five disks with
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada*

I checked the version of pmbr and gptzfsboot, they are binary identical to the ones on the 9.0-RC2 memstick.
>How-To-Repeat:
Enable AHCI in BIOS then boot
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: