[U-Boot-Users] [PATCH] Pass full u-boot environment to booting kernel

Wolfgang Denk
2004-09-15T14:54:49Z

In message <41484664.20509@intracom.gr> you wrote:
>
> IMHO it's better to have something now that works adequately than wait
> for the best solution which may be some years away.

OK. But then let's implement something that at least has a chance of
being accepted widely, and that actually solves the problems instead
of creating new ones.

What's your opinoin about implementing Mark A. Greer's bi_recs
proposal instead?

> There's a need and this thing covers it. I'd be more than happy to

No. It causes additional problems that are not easy to solve.

> > Trying to do the same in the U-Boot environment would blow up the
> > environment and easily overflow it on most systems. Also parsing and
> > decoding the ASCII representation would slow down the Linux boot
> > process too much. Also the output of a "printenv" would become
> > unreadable, etc.
>
> Obviously systems that don't need it, won't enable it.

If your proposal works as intended, it may become the satndard
interface to pass information to the kernel, so it should work on all
systems. Also, maybe I _need_ this on a system with just a 2 kB
EEPROM. What will I do then? In such a situation the environment
space is usually tight already now. And remember that the RAM copy of
the environment is not bigger than the persistent copy (and this is
intentionally, because otherwise you run into trouble when trying to
"saveenv").

> And I don't think that searching the environment for a couple of variables
> is going to be a perceptible slowdown.

No matter how much it is, it is wasted effort. There are systems
where each millisecond is precious.

> I'm open to suggestions.

See above. What about Mark's proposal? And what shall we do with the
OCP stuff?

Best regards,

Wolfgang Denk

--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
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