Re: [Xen-devel] [RFC 24/29] xen/arm: Don't use pl011 UART by default for early printk

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Tue, 2013-04-30 at 14:57 +0100, Julien Grall wrote:
> On 04/30/2013 02:51 PM, Ian Campbell wrote:
> 
> > On Tue, 2013-04-30 at 14:39 +0100, Julien Grall wrote:
> >> On 04/30/2013 01:44 PM, Ian Campbell wrote:
> >>
> >>> On Tue, 2013-04-30 at 12:21 +0100, Julien Grall wrote:
> >>>> Missing Xen devel mailing list.
> >>>
> >>> Ignore my private reply, I've inserted it below...
> >>>
> >>>>         
> >>>>         Thanks. Even if we gate CONFIG_EARLY_PRINTK to debug=y, we
> >>>>         should let the developper the option to disable/enable early
> >>>>         printk. Otherwise we will lost debug when Xen can boot on
> >>>>         multiple board.
> >>>
> >>> I'm not sure I follow, these are both valid
> >>>         debug=y CONFIG_EARLY_PRINTK=pl011
> >>>         debug=y /* No early printk */
> >>> In the latter case you have debug on a system which can boot on multiple
> >>> boards.
> >>>
> >>> Or are you concerned about not being able to build a production
> >>> (non-debug) hypervisor with early-printk? i.e.
> >>>         debug=n CONFIG_EARLY_PRINTK=pl011
> >>> ?
> >>
> >> It's the first one. CONFIG_EARLY_PRINTK should not be enabled on a
> >> production build.
> > 
> > I'm still confused what your concern is.
> > 
> > A build with debug=y is not a production build.
> 
> 
> I was not sure whether debug=y should imply CONFIG_EARLY_PRINTK or not.

Ah, no, rather the other way round -- earlyprintk is allowed only if
debug=y.

I'm not 100% sure that's a good idea, no doubt someone will soon come up
with an early boot failure which only happens on production builds...

Ian.


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