> In any case, the panic proved to be "panic: boot device not known".
> This is somewhat confusing, because the disk I'm booting from does show
> up on the messages.

[ ...]

> sbus0 at mainbus0 ioaddr 0xf8000000: clock = 25 MHz
> esp0 at sbus0 slot 0 offset 0x800000 pri 3: ESP100 25Mhz, target 7
> scsibus0 at esp0
> esp0 targ 1 lun 0: <FUJITSU, M2263S-512, 0194> SCSI1 0/direct fixed
> sd0 at scsibus0: 642MB, 1658 cyl, 15 head, 512 bytes/sec
> 
> That's the boot disk, alright.  Problem one: why does it think that
> device is "not known"?

Because the bootpath code assumes that unit 3 == sd0. It's very hard
to fix, but I think I know how to do it now. Expect something perhaps
in a week or so.

In the meantime, put your disk at scsi unit 3. That's where it has
always needed to be for NetBSD to work, after all, unless you are
running a hacked config.