[U-Boot] [PATCH v4] Add initial support for Wandboard dual lite and solo.

Scott Wood scottwood at freescale.com
Thu Mar 14 23:17:19 CET 2013


On 03/14/2013 04:01:59 PM, Tom Rini wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 03/14/2013 04:36 PM, Wolfgang Denk wrote:
> > Dear Tom,
> >
> > In message <20130314173648.GX23324 at bill-the-cat> you wrote:
> >>
> >>>> Is there any reason for not chosing the more standard 5
> >>>> second delay?
> >>>
> >>> Ok, so let's go with 3 seconds then ;-)
> >>
> >> There's a pretty even distribution of 1 3 and 5 second delays
> >> (with a few 10s, 2s and 6s).  If they want 1, let them have 1,
> >> it's not hard to break into, you have U-Boot starting + 1sec.
> >
> > The question is who "they" are.  My vote is for 5 :-)
> >
> > A quick AWK oneliner in include/configs finds this statistics:
> 
> OK, I forgot to sub -1 from 1, oops.  So it's not very even, but...
> 
> >
> > Value Count -1:    49 0:    12 1:    59 2:    30 3:   150 5:   175
> > 6:    14 10:    38 20:     1
> 
> We have a lot of variation and no "standard" aside from "board
> maintainer picks".  While I'd strongly question anyone who did > 10 I
> think this is a board maintainer decision.

It looks like a lot of the 10s are Freescale reference boards... I  
don't think it was a conscious decision there, just something that got  
copied and pasted.  We generally use 3 seconds internally in our board  
farm.

As for the default, does it make sense to autoboot at all?  What are  
the odds that the default configuration works as is (e.g. network  
configuration or images in flash)?  And personally, I find autoboot  
quite annoying during development (except for booting a secondary flash  
bank from a locked primary bank) -- it just adds risk of booting the  
new kernel before it's ready (or adds time if I have to wait until the  
new kernel's ready before I reboot).

> Now, if you've convinced
> Fabio that 5 or 3 just makes more sense than 1 for all the right
> reasons, great.  But "I think 1 is too short" isn't a good one.  1 is
> plenty of time to get a keypress in and stop the boot given that you
> have roughly from u-boot starting to press any key, not just when the
> countdown is going.  Unless you have a bug in your timer code :)

It's barely enough time if I'm watching for it, ready to pounce (and  
network lag doesn't strike at the wrong moment) -- but otherwise it's  
an extra reboot (or jamming Ctrl-C at a not-working network load until  
it finally listens) if I'm not expecting it (new environment, or  
someone else used the board last, etc).

-Scott


More information about the U-Boot mailing list