BeagleBone Black does not boot -current (DTB incompatibility?)

The last couple of snapshots of -current fail to boot on BeagleBone
Black (armv7 GENERICSD).  I have no idea how long this has been failing.
(13.1 runs.)

It appears that a malloc from ti_sysc_attach or ti_sysc_attach_clocks
is passing a size of 0, which maybe could happen if the FDT has a "clocks"
node but no clocks are found.  The console output including backtrace is
below.

I replaced the dtb directory with the one from 13.1, and the system boots
and seems to run.  I don't know my way around the armv7 DTS files, but
I'm happy to investigate if someone can point me in the right direction.

		Mike

...
No PSCI/SMCCC call function found
Texas Instruments AM335x Processor, Revision ES2.1
arc4random: WARNING: initial seeding bypassed the cryptographic random device because it was not yet seeded and the knob 'bypass_before_seeding' was enabled.
random: entropy device external interface
kbd0 at kbdmux0
ofwbus0: <Open Firmware Device Tree>
ti_sysc0: <TI SYSC Interconnect> on ofwbus0
panic: Assertion size > 0 failed at /usr/src/sys/kern/subr_vmem.c:1332
cpuid = 0
time = 1
KDB: stack backtrace:
db_trace_self() at db_trace_self
	 pc = 0xc05d793c  lr = 0xc007a9ec (db_trace_self_wrapper+0x30)
	 sp = 0xc0f14a98  fp = 0xc0f14bb0
db_trace_self_wrapper() at db_trace_self_wrapper+0x30
	 pc = 0xc007a9ec  lr = 0xc02e8880 (vpanic+0x140)
	 sp = 0xc0f14bb8  fp = 0xc0f14bd8
	 r4 = 0x00000100  r5 = 0x00000000
	 r6 = 0xc07395ef  r7 = 0xc0afb960
vpanic() at vpanic+0x140
	 pc = 0xc02e8880  lr = 0xc02e8660 (dump_savectx)
	 sp = 0xc0f14be0  fp = 0xc0f14be4
	 r4 = 0x00000000  r5 = 0xc20e0000
	 r6 = 0x00000000  r7 = 0xc0f14c50
	 r8 = 0xc0b6db00  r9 = 0x00000002
	r10 = 0xc0f14c2c
dump_savectx() at dump_savectx
	 pc = 0xc02e8660  lr = 0xc0358e14 (vmem_xalloc)
	 sp = 0xc0f14bec  fp = 0xc0f14c20
vmem_xalloc() at vmem_xalloc
	 pc = 0xc0358e14  lr = 0xc059dae4 (kmem_malloc_domainset+0x9c)
	 sp = 0xc0f14c28  fp = 0xc0f14c70
	 r4 = 0xc0048cf4  r5 = 0xc0e0d108
	 r6 = 0xc0f14c18  r7 = 0x00000000
	 r8 = 0xc20e0000  r9 = 0x00000000
	r10 = 0xc0f14c50
kmem_malloc_domainset() at kmem_malloc_domainset+0x9c
	 pc = 0xc059dae4  lr = 0xc02c1b3c (malloc_large+0x2c)
	 sp = 0xc0f14c78  fp = 0xc0f14c88
	 r4 = 0xc08f5864  r5 = 0x00000dbc
	 r6 = 0x00000000  r7 = 0x00000002
	 r8 = 0x00000dbc  r9 = 0xc07a4919
	r10 = 0xc27506c0
malloc_large() at malloc_large+0x2c
	 pc = 0xc02c1b3c  lr = 0xc06ad75c (ti_sysc_attach+0x19c)
	 sp = 0xc0f14c90  fp = 0xc0f14cd0
	 r4 = 0xd00d3e00  r5 = 0x00000dbc
	 r6 = 0xffffffff  r7 = 0xd00d3e28
ti_sysc_attach() at ti_sysc_attach+0x19c
	 pc = 0xc06ad75c  lr = 0xc032873c (device_attach+0x4f0)
	 sp = 0xc0f14cd8  fp = 0xc0f14d20
	 r4 = 0xc2757d80  r5 = 0xc2758200
	 r6 = 0x2eb77a5c  r7 = 0x00000000
	 r8 = 0xc0b72564  r9 = 0xc078651d
	r10 = 0xc27506c0
device_attach() at device_attach+0x4f0
	 pc = 0xc032873c  lr = 0xc03281b0 (device_probe_and_attach+0x8c)
	 sp = 0xc0f14d28  fp = 0xc0f14d40
	 r4 = 0xc2757d80  r5 = 0xc276da80
	 r6 = 0x5e4a6f28  r7 = 0xffffffff
	 r8 = 0x00000000  r9 = 0x00000000
	r10 = 0xc27508e0
device_probe_and_attach() at device_probe_and_attach+0x8c
	 pc = 0xc03281b0  lr = 0xc0329bb8 (bus_generic_attach+0x1c)
	 sp = 0xc0f14d48  fp = 0xc0f14d50
	 r4 = 0xc2757d80  r5 = 0x00000000
	 r6 = 0xc0f14d60 r10 = 0xc27508e0
bus_generic_attach() at bus_generic_attach+0x1c
	 pc = 0xc0329bb8  lr = 0xc00e4ce0 (ofwbus_attach+0x138)
	 sp = 0xc0f14d58  fp = 0xc0f14d90
	 r4 = 0xc2758200 r10 = 0xc27508e0
ofwbus_attach() at ofwbus_attach+0x138
	 pc = 0xc00e4ce0  lr = 0xc032873c (device_attach+0x4f0)
	 sp = 0xc0f14d98  fp = 0xc0f14de0
	 r4 = 0xc2758200  r5 = 0xc2758300
	 r6 = 0x2e0a372a  r7 = 0x00000000
	 r8 = 0xc0b72564  r9 = 0xc078651d
device_attach() at device_attach+0x4f0
	 pc = 0xc032873c  lr = 0xc03281b0 (device_probe_and_attach+0x8c)
	 sp = 0xc0f14de8  fp = 0xc0f14e00
	 r4 = 0xc2758200  r5 = 0xc276da80
	 r6 = 0x5e4a6f28  r7 = 0x00000000
	 r8 = 0xc0b094ac  r9 = 0xc0b094b0
	r10 = 0xc0aeb014
device_probe_and_attach() at device_probe_and_attach+0x8c
	 pc = 0xc03281b0  lr = 0xc032a62c (bus_generic_new_pass+0xb4)
	 sp = 0xc0f14e08  fp = 0xc0f14e20
	 r4 = 0xc2758200  r5 = 0xc08eb898
	 r6 = 0xc08c602c r10 = 0xc0aeb014
bus_generic_new_pass() at bus_generic_new_pass+0xb4
	 pc = 0xc032a62c  lr = 0xc032a678 (bus_generic_new_pass+0x100)
	 sp = 0xc0f14e28  fp = 0xc0f14e40
	 r4 = 0xc2758300  r5 = 0xc08eb898
	 r6 = 0xc2759680  r7 = 0x00000000
	 r8 = 0xc0b094ac r10 = 0xc0aeb014
bus_generic_new_pass() at bus_generic_new_pass+0x100
	 pc = 0xc032a678  lr = 0xc03256b8 (bus_set_pass+0x54)
	 sp = 0xc0f14e48  fp = 0xc0f14e60
	 r4 = 0x7fffffff  r5 = 0xc08eb898
	 r6 = 0xc2759680  r7 = 0xc274f6c0
	 r8 = 0xc0b094ac r10 = 0xc0aeb014
bus_set_pass() at bus_set_pass+0x54
	 pc = 0xc03256b8  lr = 0xc0271788 (mi_startup+0x2b0)
	 sp = 0xc0f14e68  fp = 0xc0f14e90
	 r4 = 0xc0aeb018  r5 = 0x0fffffff
	 r6 = 0xc27a3348  r7 = 0xc08bf85c
	 r8 = 0x00000000  r9 = 0x03800000
mi_startup() at mi_startup+0x2b0
	 pc = 0xc0271788  lr = 0xc0000344 (btext+0x144)
	 sp = 0xc0f14e98  fp = 0x00000000
	 r4 = 0xc0000480  r5 = 0xc0ba8000
	 r6 = 0x00000005  r7 = 0x00c52078
	 r8 = 0xc0e25000  r9 = 0x9cf00168
	r10 = 0x00000000
btext() at btext+0x144
	 pc = 0xc0000344  lr = 0xc0000344 (btext+0x144)
	 sp = 0xc0f14e98  fp = 0x00000000
KDB: enter: panic
[ thread pid 0 tid 100000 ]
Stopped at      kdb_enter+0x54: ldrb    r15, [r15, r15, ror r15]!