Code review request: boards on AT91

[M. Warner Losh]

In message: <20081125220040.c8996e0b.stas at FreeBSD.org>
            Stanislav Sedov <stas at FreeBSD.org> writes:
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: On Tue, 25 Nov 2008 11:36:47 -0700 (MST)
: "M. Warner Losh" <imp at bsdimp.com> mentioned:
: 
: > : 
: > : I think we could pass the board type via a special kenv variable
: > : for now. I think it will work fine and applicable to all supported
: > : architectures. We could probably reuse board type constants that Linux
: > : kernel uses.
: > 
: > Right now that's passed in from uboot and other loaders in I think r3,
: > but I'd have to go look at some other code to be sure.
: > 
: 
: Well, I don't think we want to follow The Linux kernel argument passing
: paradigm... But using a simple kenv variable would be just fine.
: We have a patch ready for kenv/hints support in u-boot and in
: our arm port, and our loader could be used on arm with Rafal's
: u-boot API.

You are assuming that /boot/loader is always used.  In the cases where
it isn't, we need that value from r3.  when it is, a kenv could be
used.  This switching likely also needs to be configurable more easily
than it is now.

Warner