[U-Boot-Users] Field upgrade

[Wolfgang Denk]

In message <3FCD25F8.4080308 at 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
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