[U-Boot] [PATCH 3/8] boottime: Add core boottime measurement support

Wolfgang Denk
2012-11-21T13:44:24Z

Dear Lee Jones,

In message <20121121095045.GI28265@gmail.com> you wrote:
>
> Yes, I intend to extend this functionality into Device Tree.
> That way it will be architecture and OS independent.
>
> > And forcing something upon a mechanism that was designed for a
> > completely different purpose, where you see right from the first
> > glance that it does not math easily?
>
> Not entirely sure what you mean here. This mechanism works
> perfectly with ATAGs.

Neither ATAGS not the device tree are intended nor designed for
passing logfile information. Yes, you can use them like that, and it
will actually work. You can also drive a nail in using a microscope
as hammer.

> > The advantages should be obvious: we will need no extra kernel
> > modification, we do not depend on ATAGS, and we are automatically
> > architecture-independent.
>
> Wouldn't this clog up the kernel's log buffer? I'm sure no
> user wants to see reams of otherwise useless logging scrawled
> throughout their bootlog. We'd also have a write a text parser
> to obtain the information for processing. It would be easier
> to either pass in a struct, as we do with the ATAG mechanism,
> or though Device Tree as previously discussed.

I think these are pretty poor arguments. There are standard methods
(like log levels) to provide adequate filtering of which messages are
passed on to a user. An there exists a plethora of tools for
automatic filtering and post-processing of syslog messages. You will
need to write _less_ code than with your homebrew implementation.

Best regards,

Wolfgang Denk

--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
And now remains That we find out the cause of this effect, Or rather
say, the cause of this defect... -- Hamlet, Act II, Scene 2