[U-Boot] A command to discard saved environments?

[Wolfgang Denk]

Dear James,

In message <fcff97bb-d146-fc77-28e4-050cac0922f4 at gmail.com> you wrote:
> I know my non-volatile copy of the environment is in NOR flash so I use 
> the command
> 
> protect all off;erase <saved env address> +1
> 
> But, of course this is specific to NOR flash.
> 
> I'm not aware of a way to do this in the general case, independent of NV 
> environment storage media and redundancy.

The idea applies to all kinds of persistent storage: just overwrite a
few (4 or more) bytes at the beginning of each copy of the persistent
envrionment.

In your case, you could save the "erase" by overwriting the first 4
bytes (where the CRC32 checksum is stored) with 0xFFFFFFFF.

> I'd be supportive of having a way to do this.

No, I don't think we want to support this.  The persistent copy of the
environment is a precious resource, and I cannot think of a regular
use case to invalidate this.  If you do, the result is that you will
use the default settings at next boot - and the samve effect can be
acchieved by using "env reset" + "env save" as already recommended.
[The only difference is that you will not see the "invalid CRC, using
the default env" warning then, but I consider this a pro, not a con.]

Best regards,

Wolfgang Denk

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