In article <200602171444.k1HEibg6000080@guild.plethora.net> you write:
>Anyway, if there's any obvious points to look at for "machine reboots long
>before console attach", I wouldn't mind pointers.

It's a long time since I played with this kind of thing when first getting
NetBSD/arm26 (as it was then) to go, but I remember some of the techniques I
used.  I wrote a little piece of assembler that would do something obvious
if it got executed.  One of these filled screen memory with a particular
colour, for instance.  In your case, an infinite loop might be a good start,
since you can tell the difference between that and a reboot.  Then I
inserted this code at various points in the system startup to check that
everything was working.  The first place to try is right at the start of the
kernel, to make sure the bootloader's setting things going at the right
point.  Then, you can move the tell-tale code around and home in on the
point where it stops getting called.

Once you've got a working console, things get much less painful.

-- 
Ben Harris