RPI2 12.0-CURRENT r305028 bootup crash in pf

[G. Paul Ziemba]

hps at selasky.org (Hans Petter Selasky) writes:

>This error is likely due to trying to enter KDB. Can you use a newer 
>kernel revision. It has some extra USB patches to avoid KDB from 
>crashing like this.

I appreciate your response, thank you!

I obtained sources 15 Sep 2016 14:38 PDT via svn from
https://svn0.us-west.freebsd.org/base/head and built with crochet,
resulting in FreeBSD-armv6-12.0-RPI2-305849.img.

It looks like about the same result (to me anyhow, maybe you
will spot a critical difference). The following output occurred
when I booted without a keyboard attached (again, hand-transcribed).

I tried attaching a USB keyboard at this point, but typing on it
did not yield anything on the screen. I also tried booting again
with the keyboard attached. The kernel produced a message during
boot that recognized the keyboard, but still, typing had no effect
at the "db> " prompt.

---- begin console transcription ----
Kernel page fault with the following non-sleepable locks held:
exclusive sleep mutex pf fragments (pf fragments) r = 0 (0xc4e03808) locked 0 /v2/Source/public/freebsd/pi/crochet/src/sys/modules/pf/../../netpfil/pf/pf_norm.c:224
stack backtrace:
Fatal kernel mode data abort: 'Translation Fault (L1)' on read
trapframe: 0xeb4c2d40
FSR=00000005, FAR=00000004, spsr=80000013
r0 =00000000, r1 =00000001, r2 =ffffffff, r3 =c087b774
r4 =0000000f, r5 =c4df839a, r6 =c4e03800, r7 =00000000
r8 =c4e0343c, r9 =c4e03458, r10=00000000, r11=eb4c2df0
r12=c4e03808, ssp=eb4c2dd0, slr=c02a6514, pc =c4deb88c

[ thread pid 358 tid 100084 ]
Stopped at      pf_purge_expired_fragments+0x44:       ldr    r0, [r0, #0x004]
db>
---- end console transcription ----
-- 
G. Paul Ziemba
FreeBSD unix:
10:41AM  up 26 days, 13:20, 16 users, load averages: 1.93, 2.09, 1.98