[U-Boot] imx6, spl and falcon boot

[Chaves, Kevin]

It's not so much a faster boot I'm looking for but just relying less on uboot to initialize the device. The initial idea by my superiors is make an infallible way to update uboot, since they think they'll screw it up and have to support a field update. So we wanted to make two images with uboot/kernel/rfs, one for recovery and have a way to switch the settings on startup. That way we have a small first stage boot that won't ever need to be updated so long as it can boot from two different partitions.

I realized it probably wasn't that useful to keep uboot around since the spl+falcon will increase the boot time. Figured I could kill two birds with one stone here. Faster boot, and no need to update the bootloader in the field, or at least minimize how much could change in its start up procedure so there is less to "fix" in the future.

-----Original Message-----
From: Eric Nelson [mailto:eric.nelson at boundarydevices.com] 
Sent: Tuesday, February 19, 2013 11:34 AM
To: Chaves, Kevin
Cc: Alexandre Belloni; Wolfgang Denk; u-boot at lists.denx.de; Dirk Behme
Subject: Re: [U-Boot] imx6, spl and falcon boot

Hi Kevin,

I'm a bit late to this party, but have a couple of comments...

On 02/19/2013 08:20 AM, Chaves, Kevin wrote:
> Thanks for the response, so the whoosh does not support holding
 > a key to get into another image? I guess that won't work.
 >

Note that there's already support for key-handling in our Nitrogen6X code:
	https://github.com/boundarydevices/u-boot-imx6/blob/production/board/boundary/nitrogen6x/nitrogen6x.c#L779

> So if I wanted to support the SPL on the nitrogent6x are there any 
> instruction on what requirements it has to
 > support it.
>
The use of SPL seems to be a separate topic.

Is your objective simply a faster boot?

We don't have any specific plans to add SPL support for Nitrogen6x, but are interested in hearing what you're after.

> I'm guessing all the work I'd need to do is in board/boundary/nitrogen6x?
 >  Also how would I normally configure and build an spl for  > a working board. There is a lot of config options  > in the README for the spl.
>
> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni at piout.net]
> Sent: Tuesday, February 19, 2013 9:00 AM
> To: Wolfgang Denk
> Cc: Chaves, Kevin; u-boot at lists.denx.de; Dirk Behme
> Subject: Re: [U-Boot] imx6, spl and falcon boot
>
> On Tue, Feb 19, 2013 at 12:35:01PM +0100, Wolfgang Denk wrote :
>> Dear Alexandre Belloni,
>>
>> In message <20130219112532.GB24397 at piout.net> you wrote:
>>>
>>> No, that is not supported and probably won't be. Some people will 
>>> argue
>>
>> I think you are wrong.  This is definitely a "not supported _yet_".
>>
>>> that you probably don't need a bootloader once you are able to boot 
>>> a linux kernel as you can probably do everything you want from there.
>>
>> Yes, some people will think so, and some will actually do that.
>> Others (and I would expect these to be the majority) will realize the 
>> benefits of being able to switch on demand (say, key press, jumper 
>> setting, etc.) between different boot modes, boot images, etc.
>>
>> I am absolutely sure that SPL support for iMX6 will be added rather 
>> sooner than later.
>>
>
> Yeah, don't misinterpret me, I was just saying that it will not be
 > supported in whoosh. I also believe that SPL and falcon mode will  > come to i.mx6 and I'm also interested in getting that support ;)
>

Whoosh seems pretty compelling with such a small code base.
Does it really boot faster though? Do you have any numbers for TTP (Time-to-penguin) on a SABRE Lite or SABRE SD?

Regards,


Eric