[U-Boot-Users] Field upgrade

Wolfgang Denk
2003-12-03T00:29:11Z

In message <3FCD25F8.4080308@corelatus.com> you wrote:
>
> Well, if you want to be able to safely upgrade u-boot in field, you
> have two choices.

U-Boot is not special in this respect. Either you treat U-boot as
boot loader, or as application package.

> a) Do it in hardware
> Requires you to have control over card design.
>
> b) Do it in software
> Can be done on "any" card.

I don't know of a reliable way to field-update the boot loader.
Period.

> * If you make an error in your pre u-boot program, you may
> have to upgrade it. If so, card will die if something
> happens while you rewrite that sector.

You just shifted levels. U-Boot becomes an application, and the
problem still exists with your new (smaller, simpler) boot loader.

You added complexity and duplicated code (for example to check the
CRC's). In general that means that your system is more likely to have
errors than a simpler system.

> Which solution is better?

This was not a question. The question was about a reliable way for a
field upgrade of the boot loader.

There is none, except with special hardware support.

Let's stop this fruitless discussion here, please. You have a setup
which works fine for you, no doubt about that. But it does not fix
the problem discussed here.

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
To the systems programmer, users and applications serve only to
provide a test load.