[U-Boot] [PATCH 1/4] Add option -r to env import to allow import of text files with CRLF as line endings

[Alexander Holler]

Am 14.08.2014 22:08, schrieb Stephen Warren:
> On 08/14/2014 01:59 PM, Alexander Holler wrote:
>> Am 14.08.2014 21:51, schrieb Stephen Warren:
>>> On 08/14/2014 01:38 PM, Alexander Holler wrote:
>>>> Am 14.08.2014 17:49, schrieb Stephen Warren:
>>>>> On 08/14/2014 02:25 AM, Alexander Holler wrote:
>>>>
>>>>>> As I've just remembered where I did see your name before, the config
>>>>>> for
>>>>>> the rpi (as found in 2004.04) misses the uenvcmd. That's necessary to
>>>>>> execute commands when using uEnv.txt.
>>>>>>
>>>>>> It's easily done with something like the following:
>>>>>>
>>>>>>                                 "env import -t -r $loadaddr
>>>>>> $filesize;" \
>>>>>>                                 "if test -n \"$uenvcmd\"; then " \
>>>>>>                                         "echo \"Running uenvcmd
>>>>>> ...\";" \
>>>>>>                                         "run uenvcmd;" \
>>>>>>                                 "fi;" \
>>>>>
>>>>> My intention was that uEnv.txt be used to set up environment
>>>>> variables,
>>>>> not to allow its use for custom scripts.
>>>>>
>>>>
>>>> Sure. In most cases changing the predefined available variables is
>>>> enough. But it's a very hand option if someone wants or needs to do
>>>> stuff which can't be done by just changing some environment variables
>>>> (one never knows what ideas people will have).
>>>
>>> For such presumably non-standard things, why can't the user simply edit
>>> $bootcmd, and pre-pend whatever they want?
>>
>> Depends on when the bootcmd will be constructed. Usually that is done
>> after having read uEnv.txt to include variables defined in uEnv.txt in
>> bootcmd. So whatever bootcmd one sets in uEnv.txt, it just will be
>> overwritten.
>
> What would over-write bootcmd? None of the boards I've looked at
> auto-generates bootcmd. bootargs perhaps (which is a string passed to
> the kernel) but not bootargs (which is a U-Boot command sequence that
> U-Boot executes automatically at boot).
>
> If some board does auto-generate bootcmd, I'd suggest that it not. The
> static bootcmd could execute some kind of user-(or uenv-)set variable
> and/or the auto-generation of bootcmd could happen before uenv.txt was
> pulled in, so that whatever was in uenv.txt would have ultimate "power".

Ah, yes. Sorry, I confused bootcmd with bootargs (I don't live in u-boot 
and just fiddle once a year or such with it).

But overwriting bootcmd needs to read uEnv.txt in PREBOOT (or how it is 
named). I originally have read uEnv.txt in the bootcmd itself, so 
overwriting it didn't work. But I don't want to dive too deep into that 
discussion, as I think it's up to the board-maintainers to write the 
config however they want and seem to fit for there users. I've just 
mentioned the uenvcmd, because it was the first, I've added to my u-boot 
for the rpi (to have the same interface I use with my other boards). ;)

Regards,

Alexander Holler