netbsd-10 & current aren't booting on AlphaServer DS25

Hello, Alpha fans,

My last OS update on my AlphaServer DS25 was in May, and the machine has 
been up and stable since. I wanted to try NetBSD 10, but it didn't get 
far. Tested both GENERIC + MSGBUFSIZE=32760, maxusers 128, options 
GATEWAY, and just GENERIC:


NetBSD/alpha 9.99.88 FFSv2 Primary Bootstrap
Jumping to entry point...

NetBSD/alpha 9.99.88 Secondary Bootstrap, Revision 1.13 (Sat Aug 28 15:29:44 UTC 2021)

VMS PAL rev: 0x2002b00010162
OSF PAL rev: 0x200210002015c
Switch to OSF PAL code succeeded.

Boot file: netbsd
Boot flags: a
13448816+233696 [652920+424897]=0xe14148

Entering netbsd at 0xfffffc0000a014a0...
[   1.0000000] consinit: not using prom console
[   1.0000000] Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
[   1.0000000]     2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
[   1.0000000]     2018, 2019, 2020, 2021, 2022
[   1.0000000]     The NetBSD Foundation, Inc.  All rights reserved.
[   1.0000000] Copyright (c) 1982, 1986, 1989, 1991, 1993
[   1.0000000]     The Regents of the University of California.  All rights reserved.

[   1.0000000] NetBSD 10.0_BETA (GENERIC-$Revision: 1.416 $) #0: Tue Dec 27 19:37:36 UTC 2022
[   1.0000000]  [email protected]:/usr/obj-alpha/sys/arch/alpha/compile/GENERIC
[   1.0000000] AlphaServer DS25, 1000MHz, s/n 4239KW51A0
[   1.0000000] 8192 byte page size, 2 processors.
[   1.0000000] total memory = 12288 MB
[   1.0000000] (7352 KB reserved for PROM, 12280 MB used by NetBSD)
[   1.0000000] avail memory = 12098 MB

[   1.0000000] CPU 0: fatal kernel trap:

[   1.0000000] CPU 0    trap entry = 0x2 (memory management fault)
[   1.0000000] CPU 0    a0         = 0xfffffffd80c025c0
[   1.0000000] CPU 0    a1         = 0x1
[   1.0000000] CPU 0    a2         = 0x0
[   1.0000000] CPU 0    pc         = 0xfffffc0000a52a94
[   1.0000000] CPU 0    ra         = 0xfffffc000106b2d0
[   1.0000000] CPU 0    pv         = 0xfffffc0000a52a20
[   1.0000000] CPU 0    curlwp     = 0xfffffc00016b6700
[   1.0000000] CPU 0        pid = 0, comm = system

[   1.0000000] panic: trap
[   1.0000000] cpu0: Begin traceback...
[   1.0000000] alpha trace requires known PC =eject=
[   1.0000000] cpu0: End traceback...
Stopped in pid 0.0 (system) at  netbsd:cpu_Debugger+0x4:        ret     zero,(ra)
db{0}>


Does anyone have thoughts about what to try next?

John