[U-Boot-Users] RFC: hidden environment variables

Ulf Samuelsson ulf at atmel.com
Mon Apr 23 20:47:00 CEST 2007

> WD et al:
> I'd like to propose a new feature for U-Boot: hidden environment variables.  These are 
> variables that are stored in environment but are normally not visible to the user. 
> Specifically, a hidden environment variable would have these properties:
> 1) Doesn't show up via "print" or "echo"
> 2) Can't be referenced via a $
> 3) Can't be set via setenv

I think an attribute byte for each variable would be nice.
Then you can have attributes like:

user editable

I would for instance like to treat ethaddr differently.
This should be freely changeable until it is locked.

I would also like to get rid of the "run" command
and execute commands directly.
These commands would be referencing commands which does not need to be visible.

> Only internal U-Boot code can modify/query these variables.  This way, internal code can 
> use the existing environment data structure without having to expose this data to the user 
> (and giving him the impression that he can access/manipulate this data directly).
> The only drawback to this plan is that, after modifying a hidden environment variable, the 
> user would need to be told to issue "saveenv" if he wants his changes saved permanently.
> One advantage of this feature is that we can develop new commands that store data 
> permanently without having to add hooks into _do_setenv().
> -- 
> Timur Tabi
> Linux Kernel Developer @ Freescale

Best Regards
Ulf Samuelsson                ulf at atmel.com
Atmel Nordic AB
Mail:  Box 2033, 174 02 Sundbyberg, Sweden
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