[U-Boot] Re

[Frank Ihle]

Hello Stefano


>>>> Stefano Babic <sbabic at denx.de> 07.04.14 18.07 Uhr >>>
>Hi Frank,
>
>On 07/04/2014 15:49, Frank Ihle wrote:
>> Hi U-Boot,
>> 
>> you recently gave me the hint about the Falcon Mode for my Fast
>> Booting investigations. But I think might got it wrong, could
>> somebody correct me if so?:
>> 
>> - According to the "Falcon Mode" Pdf of October 2013
>> (http://www.denx.de/wiki/pub/U-Boot/MiniSummitELCE2013/2013-ELCE-U-Boot-Falcon-Boot.pdf)
>> The Falcon mode is just about to chose 2 different execution modes
>> during startup - one that starts Linux directly (and skips u-boot)
>> and the other for instance to make updates, or failsafe mode (and
>> starts u-boot). Or does it even contain more functionality ?
>
>The second starts U-Boot as you are used to.

agreed

>> - According to the "Minimizing boot times using U-Boot Falcon Mode"
>> Pdf of July 2012 
>> (http://schedule2012.rmll.info/IMG/pdf/LSM2012_UbootFalconMode_Babic.pdf)
>> it's mentioned that this can only run with boards, which are able to
>> work with SPL. I guess here SPL means Second Programm Bootloader. I'm
>> not an expert in this area, but wouldn't it be possible to run every
>> board with an SPL, since it's just Software like a Bootloader?
>
>Of course, but not all boards supported in mainline were converted to
>use SPL, and for this reason not all boards support out of the box
>Falcon Mode.

So
 this "part" of including more and more boards is up to the U-Boot team,
 not of the Board developer ? ( except one would like to do this by 
himself .. )

>> And if
>> not what is the "real" eye of the needle here ? I'm just asking
>> because I didn't get the problem here.
>
>It is simply a snapshot of the current U-Boot mainline. The switch
>between Linux/U-Boot is implemented in SPL, and this makes sense because
>SPL is much smaller that the whole U-Boot, dropping also the time that a
>SOC needs to load an image from the storage media.

That's
 what I understood too. I gotta say, this sounds like a working 
alternative to skipping U-Boot completely when it comes too keep the 
boot times at their lowest, I like that implementation.

Kind Regards,

Frank