sparc64 boot failure after 7.9 upgrade

Hey all.  So, I solved this problem, but I didn't find any mention of it =
when
I was looking around the internets when it first occurred.  Wanted to =
ask here.

I have a Sun T5120 system running OpenBSD, using softraid (RAID1) for =
boot.
The OBP configuration is odd IMO, and I don=E2=80=99t remember whether I =
ever
understood it, or if I just found something that worked and left it.  It
was (at least for 7.4 through 7.8):

----8<----8<----8<----
Variable Name           Value                          Default Value
[..]
boot-command            boot                           boot
boot-file               sr0absd
boot-device             disk0                          disk net
----8<----8<----8<----

For the boot loader identifying as ">> OpenBSD BOOT 1.27" through and
including =E2=80=9C1.29=E2=80=9D, this was what worked:

----8<----8<----8<----
Boot device: disk0  File and args: sr0absd
OpenBSD IEEE 1275 Bootblock 2.1
>> OpenBSD BOOT 1.29
ERROR: /iscsi-hba: No iscsi-network-bootpath property
sr0*
Booting sr0a:/bsd
10302872@0x1000000+2664@0x19d3598+149044@0x1c00000+4045260@0x1c24634
symbols @ 0xfe926400 513783+165+678696+474168 start=3D0x1000000
----8<----8<----8<----

Upgrading OpenBSD from 7.7 to 7.8 worked fine. This stayed the same.
However when I upgraded to OpenBSD 7.9, it seems to have upgraded the
boot loader to 1.30, and this now failed:

----8<----8<----8<----
Boot device: disk0  File and args: sr0absd
OpenBSD IEEE 1275 Bootblock 2.1
>> OpenBSD BOOT 1.30
ERROR: /iscsi-hba: No iscsi-network-bootpath property
sr0*
open sr0a:/absd: No such file or directory

Boot:
----8<----8<----8<----

After searching around but not finding any reference, and then some =
obvious
trial and error, I was able to determine that the =E2=80=9Cright" string =
to use for
my boot-file is now "sr0bsd=E2=80=9D.

So, do we know what changed in 1.30 compared to 1.29, and shouldn=E2=80=99=
t this be
mentioned in the upgrade guide?   I thought I found an arch-specific =
upgrade
notes page, but can=E2=80=99t right now, so maybe I immagined it.
Let me know if I failed to find/read the riught info if this was already =
a
documented need to change config.

-Chris



ps, current boot output:

Boot device: disk0  File and args: sr0bsd
OpenBSD IEEE 1275 Bootblock 2.1
>> OpenBSD BOOT 1.30
ERROR: /iscsi-hba: No iscsi-network-bootpath property
sr0*
Booting sr0a:/bsd
10613032@0x1000000+3800@0x1a1f128+152092@0x1c00000+4042212@0x1c2521c
symbols @ 0xfe912400 544701+165+709944+498410 start=3D0x1000000