[U-Boot] Very confusing variable=name behaviour

[Peter Barada <peter.barada@logicpd.com>]

In u-boot there are two types of variables, local and persistent variables.

Persistent variables are assigned via "setenv", can be saved (the whole 
environment) via "saveenv", restored (to default values) via "env 
default -f".

Hush variables are assigned via "=" and can aren't saved.

Both are accessed via "$variable" or "${variable}"

What you are seeing is normal.


On 12/12/2015 03:53 PM, Pavel Machek wrote:
> Hi!
>
> I'm getting quite crazy behaviour of variables in recent u-boot:
>
> VERSION = 2016
> PATCHLEVEL = 01
> SUBLEVEL =
> EXTRAVERSION = -rc1
>
>
> Bytes transferred = 104656 (198d0 hex)
> => bootm_boot_mode=nonsec
> => echo $bootm_boot_mode
> nonsec
> => prinetenv bootm_boot_mode
> Unknown command 'prinetenv' - try 'help'
> => printenv bootm_boot_mode
> ## Error: "bootm_boot_mode" not defined
> => echo $bootm_boot_mode
> nonsec
> =>
>
> What is going on there? C-level  "getenv" fails on such variable, too.
>
> bootm_boot_mode = '<NULL>'
>
> Explicit setenv behaves as expected:
>
> => setenv bootm_boot_mode nonsec
> => echo $bootm_boot_mode
> nonsec
> => printenv bootm_boot_mode
> bootm_boot_mode=nonsec
> =>
>
> Best regards,
>
>       	      	 			       	       		 Pavel

-- 
Peter Barada
peter.barada at logicpd.com