>> I can read and write the entire image using dd(1), irrespective of
>> geometry and I have used disksim to build an image using the second
>> geometry, but installing this on the flash has not made it possible to
>> boot a Plan 9 kernel.

>
> the fact that you can dd but can't boot a kernel hints that
> the problem might not be with the ide flash.
>
> could you explain more about what happens when you try
> to boot from this device?