Rebooting a Fire V240 with a different kernel

[Frank Wille <frank%phoenix.owl.de@localhost>]

Hi,

I do not get how the boot command in OpenBoot and ofwboot works, and I'm 
probably confused.

I got one of my old Fire V240 systems out of the basement, which ran 
with NetBSD 6.1.5 many years ago, and would like to upgrade it to 11. I 
copied the new kernel to /netbsd11 and the new ofwboot to /ofwboot11. Is 
there a chance to boot that kernel in single user mode to see if it works?

In OBP I tried
{1} ok boot disk netbsd11 -s

which obviously didn't work:

---8<---
SC Alert: Host System has Reset
Probing system devices
Probing memory
Probing I/O buses

Sun Fire V240, No Keyboard
Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
OpenBoot 4.17.1, 2048 MB memory installed, Serial #6408xxxx.
Ethernet address 0:3:ba:d1:xx:xx, Host ID: 83d1d1ef.



Rebooting with command: boot disk netbsd11 -s
Boot device: /pci@1c,600000/scsi@2/disk@0,0  File and args: netbsd11 -s
NetBSD IEEE 1275 Multi-FS Bootblock
Version $NetBSD: bootblk.fth,v 1.13 2010/06/24 00:54:12 eeh Exp $
>> NetBSD/sparc64 OpenFirmware Boot, Revision 1.16
Failed to load 'netbsd11'.
---8<---

Looks like the old /ofwboot was loaded. How did that happen, when I 
didn't specify it at the boot prompt?

Anyway, it doesn't load the new kernel, and I cannot make OBP to load 
/ofwboot11 instead.

When I enter the current kernel, "netbsd", at the ofwboot boot prompt, 
then it will load. But not netbsd11.

How can I tell OpenBoot to use an updated /ofwboot? Or what is my best 
upgrade path?

--
Frank Wille