new ARM hardware platform - help wanted

[David Barrass]

Myself and a colleague are developing a new Cortex-A9-based router. I 
would like to use OpenBSD as the O.S. for reasons of the security 
credentials that OpenBSD has.
I have made a start in getting OpenBSD running on the hardware but at 
the moment, the only tool I can use for debugging is a JTAG debugger as 
I am working on getting a serial-port driver working. I would very much 
appreciate some assistance from the ARM hardware gurus on this list to 
make sure that I am doing things the "OpenBSD way" and not making any 
fundamental errors through ignorance. If I was trying to get FreeBSD 
running, what I would do as a first step would be to build an image 
using the nearest supported platform. The OpenBSD sources only appear to 
use the GENERIC and RAMDISK templates. I have built the cross tools here 
on my development machine which is running OpenBSD5.9 and am using the 
source from this release as the starting-point for development.
I have a BeagleBoneBlack which runs the bsd.rd.OMAP.umg from the 6.0 
tree. I then tried building a BEAGLEBONE image using the RAMDISK 
template as my starting point. This works and produces a bsd ELF-32 
kernel image. I can tftp this across to the BeagleBoneBlack using the 
U-boot that comes with the board but when I try running this, bootm does 
not recognize the image as a valid one.
What I would appreciate in the first instance is a list of step-by-step 
instructions on how to recreate the bsd.rd.OMAP.umg image on my 
development machine in order to validate the build process and build 
environment on my machine. I have spent many hours looking through the 
archives of this list looking for relevant threads. In the past, I have 
worked on a PCI-based WiFi card fitted to a PC and am happy with 
building the native GENERIC kernel and hacking the source code to get 
the WiFi card working but I have never built a bsd kernel for a new 
non-x86 hardware platform. I have read the relevant config and related 
man pages and have a copy of M.W. Lucas' book "Absolute OpenBSD" book 
and read the relevant section. The code I have built for my prototype 
hardware is valid ARM code and starts to run but falls over just after 
enabling the MMU. It is falling over somewhere in the initarm function 
but I am not sure where yet.
Apologies for the length of this email - I was hoping to keep it short 
but with just enough detail to pique the interest of any guru who might 
be interested in offering some assistance and not annoy those who are 
not interested.
Thank you in anticipation.
David