Upgrade from 12.4-STABLE to 13.3-STABLE fails

Hi all, this's a ZFS root, 12.4-STABLE (r373297) system with GENERIC kernel.

I'm trying to upgrade to 13.3-STABLE - world and kernel have been built, installkernel ends with:

===> zlib (install)
install -T release -o root -g wheel -m 444   zlib.ko /boot/kernel.test/
install -T dbg -o root -g wheel -m 444   zlib.ko.debug /usr/lib/debug/boot/kernel.test/
kldxref /boot/kernel.test
kldxref: error while reading /boot/kernel.test/iwlwifi-9000-pu-b0-jf-b0-46.ucode.ko: Bad address
kldxref: error while reading /boot/kernel.test/iwlwifi-9260-th-b0-jf-b0-46.ucode.ko: Bad address


I'll assume this isn't fatal (I'm not using wifi anyway) and just continue.


The main problem is then trying to boot kernel.test. At the loader prompt either:

unload kernel
boot -s /boot/kernel.test/kernel

or

unload
load /boot/kernel.test/kernel
boot -s

ends with:


ugen0.4: <Usb KeyBoard Usb KeyBoard> at usbus0
ukbd1 on uhub2
ukbd1: <Usb KeyBoard Usb KeyBoard, class 0/0, rev 1.10/1.10, addr 3> on usbus0
kbd3 at ukbd1

Loader variables:
  vfs.root.mountfrom=zfs:zroot/ROOT/default

Manual root filesystem specification:
  <fstype>:<device> [options]
      Mount <device> using filesystem <fstype>
      and with the specified (optional) option list.

    eg. ufs:/dev/da0s1a
        zfs:zroot/ROOT/default
        cd9660:/dev/cd0 ro
          (which is equivalent to: mount -t cd9660 -o ro /dev/cd0 /)

  ?               List valid disk boot devices
  .               Yield 1 second (for background tasks)
  <empty line>    Abort manual input

mountroot>


Is this because zfs.ko isn't loaded? Am I supposed to load (all) modules at the loader prompt too?

Or is this because there's been a change with the loader in 13.x ? Should I upgrade to 13.0 first?

My /boot/loader.conf:

kern.geom.label.gptid.enable="0"
zfs_load="YES"
cpu_microcode_load="YES"
cpu_microcode_name="/boot/firmware/intel-ucode.bin"