>>>     installboot boot bootxx /dev/rsd1a
>> That's wrong, see installboot(8) for details.
> I've tried several different incantations... including
> /usr/mdec/installboot /usr/mdec/boot /usr/mdec/bootxx /dev/rsd1a
> None work.

This looks as though you're naming the "boot" in /usr/mdec.  That won't
work (unless /usr/mdec is actually in your boot partition).

You need to copy /usr/mdec/boot to the boot partition and then give
installboot the path to the copy.

You presently have to have the filesystem mounted.  This is a
conceptual crock and was presumably done because it makes installboot's
code significantly simpler.  I've some hacks to installboot that I
suspect may help with this; I need to test them.  (I think mrg has a
copy of them, and was making noises about getting them into
installboot, originally for cross-compile purposes I think.)

>     tar cpf - .[a-z]* [A-Za-ln-z]* | (cd /mnt; tar xvpf - )
> # the funny set of patterns just avoids dragging /mnt into /mnt/mnt

Heh.  It also avoids all dotfiles not beginning with a letter, and
other stuff beginning with m, as well as everything beginning with
[^.a-zA-Z]...not that / usually contains such stuff.  Usually. :->

Now, if you were using my tar, it'd be

	tar cf - * .* -X . -X .. -X mnt | ...

or even just

	tar cf - . -X ./mnt | ...

though that has the additional effect of copying the mode bits from the
old root to the new.  (This can be good or bad, depending on what you
want.)

See ftp.netbsd.org:/pub/NetBSD/misc/mouse/tar/ if you're interested in
my tar.

>     /usr/mdec/installboot /mnt/boot /usr/mdec/bootxx /dev/rsd1a
[...]
> This appears to have worked.  Thanks!

Note that installboot here was given the path to the _installed_ copy
of boot, not the /usr/mdec copy.

> So, does installboot determine the location of the boot blocks by
> examining where *physically* it is located on the disk (i.e.
> "/mnt/boot" in this case)?

Yes.

> I.e. why did my attempts fail?  And, more importantly, if I *move*
> "/boot" to a different physical place on the media (i.e. backup +
> restore), will the bootstrap no longer be able to find it (even if it
> is in the same logical place in the filesystem hierarchy...)?

Yes; you will need to rerun installboot if you do anything that makes
the data blocks move.

You can mv the file anywhere on the partition and it will be just fine;
keeping it in /boot is purely a human convention.  You can even remove
it, if you're crazy enough, and it'll continue to work until the data
blocks it used to occupy happen to get reused for something else.

But destroy it and recreate it, even with something like "cat
/usr/mdec/boot > /boot" (which will truncate it to zero size and free
all the blocks, allocating new and possibly different blocks for the
new contents), and you're asking for trouble unless you rerun
installboot.  As you can see from the above, it may appear to work if
you skip the installboot, but as soon as the data blocks whose numbers
installboot shoved into the boot program get reused (which might even
be for the new version), it will start falling over.

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