[U-Boot] Return value of run command

[Tom Rini]

On Fri, May 30, 2014 at 05:03:36PM +0200, Enric Balletbo Serra wrote:
> Hi all,
> 
> Should the command 'run something"' return the value that returns
> "something" or just return "true" if can execute something and "false"
> if it can't ?
> 
> I'll explain. Imagine you have a variable that loads a file from the
> mmc but this files doesn't exist.
> 
>   loadfile=load mmc ${mmcdev} ${loadaddr} my-file
> 
> In the case you do the following script
> 
>     if run loadfile; then  echo "true"; else echo "false"; fi
> 
> the result is always "true", either the file doesn't exist
> 
> OTOH, if you do :
> 
>     if ${loadfile}; then echo "true"; else echo "false"; fi
> 
> Then the result is "true" if file exist and "false" if file doesn't exist.
> 
> For me looks like the "run something" command should return the result
> of the command but this is not the behaviour. With current behaviour
> something like CONFIG_EXTRA_ENV_SETTINGS from
> include/configs/am335x_evm.h file,
> 
> 129                         "echo SD/MMC found on device ${mmcdev};" \
> 130                         "if run loadbootenv; then " \
> 131                                 "echo Loaded environment from ${bootenv};" \
> 132                                 "run importbootenv;" \
> 133                         "fi;" \
> 
> 
> Either uEnv.txt file exist or not, the "run loadbootenv" always
> returns true, so always tries to run "run importbootenv". I supose
> this is not the expected behaviour.
> 
> The question is. It's a problem with run command or with the
> definition of CONFIG_EXTRA_ENV_SETTING, that should be something like
> that:
> 
> - 130                         "if run loadbootenv; then " \
> + 130                         "if ${loadbootenv}; then " \

Sorry for sitting on this for so long.  There's been a change in
behaviour that I'm going to go track down now and see what we can do
about.

-- 
Tom
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