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

[Ulf Samuelsson <ulf@atmel.com>]

> 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:

hidden
user editable
locked
exectuable

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
Visit:  Kavalleriv?gen 24, 174 58 Sundbyberg, Sweden
Phone +46 (8) 441 54 22     Fax +46 (8) 441 54 29
GSM    +46 (706) 22 44 57

Technical support when I am not available:
AT90 AVR Applications Group: mailto:avr at atmel.com
AT91 ARM Applications Group: mailto:at91support at atmel.com
AVR32 Applications Group        mailto:avr32 at atmel.com
http://www.avrfreaks.net/;            http://avr32linux.org/
http://www.at91.com/ ;                ftp://at91dist:distrib at 81.80.104.162/