Thinkpad X61s cannot boot 9.1-BETA1

[jb]

Per olof Ljungmark <peo <at> intersonic.se> writes:

> ... 
> >> Did anyone else experience this? With 9.1-BETA1 the boot process
> >> freezes, among the last lines with verbose boot are
> >>
> >> acpi_acad0: On Line
> >> acpi_acad0: acline initialization done, tried 1 times
> >>
> >> after this, dead.
> >> ...
> Tried ALL boot options, none worked. For example, if I try "disable 
> acpi" it will stop at "no event timer available".

Here is something similar ...
http://forums.freebsd.org/archive/index.php/t-32423.html
...
"When I enabled verbose boot logging, the boot seems to hang up just after the
kernel load. I have tried disabling ACPI and APIC with the same results.

Here is where the news starts to turn good. I tried a FreeBSD 9 disk and got
much further. Then, I was either getting a page fault or panic: no usable event
timer found depending on boot options. The release errata then set me straight.
With debug.acpi.disabled="hostres" I was able to boot! ..."

Here is the related errata:
http://www.freebsd.org/releases/9.0R/errata.html
...
"[amd64, i386] FreeBSD 9.0-RELEASE includes several changes to improve resource
management of PCI devices. Some x86 machines may not boot or may have devices
that no longer attach when using ACPI as a result of these changes. This can be
worked around by setting a loader(8) tunable debug.acpi.disabled to hostres. To
do this, enter the following lines at the loader prompt:

set debug.acpi.disabled="hostres"
boot

Or, put the following line into /boot/loader.conf:

debug.acpi.disabled="hostres"
..."

Anyway, regardless of this attempt, file a PR# for 9.1-BETA1.
jb