[U-Boot] [PATCH 1/4] cmdline: Add linux command line munging tools

Wolfgang Denk wd at denx.de
Thu Oct 20 21:03:42 CEST 2011


Dear Doug Anderson,

In message <CAD=FV=WEk1To=hyOTLBC+htq=7hxrTqtyckajJyLByqs3DBFYA at mail.gmail.com> you wrote:
>
> I'm happy to explain.  :)  In our setup, the Linux command line is
> constructed (in part) by reading from the disk.  When we load the kernel, we
> also load the kernel command line.  It is convenient for us if this kernel
> command line on disk continues to have things like "console=/dev/ttyS0" and
> "earlyprintk" in it so that we can swap between release (no console) and
> development (with console) by just tweaking a settings in u-boot.
> 
> Certainly we could change our setup, but the prior existence
> of fixup_silent_linux() indicated that this might be a common way to do
> things.

Please check where this is actually used, and how. It serves a very
special purpose, and by todays level of reviews I seriously doubt such
code would be accepted any more.

Yes, please change your setup.  Just because you are doing things your
(highly unefficient) way does not mean I'm going to accept such code
for mainline.

> In the case of Chromium OS, we also do some additional programmatic munging
> of the command line for verified boot purposes, but since that is not
> upstream it's not really a good argument for making the more general
> function.

May I ask why you don;t use the powerful capabilities of incrementally
building the command line from environment variable settings?

[These can also be read from disk.]

> In any case, I already have the more direct (and less generalized) version
> of fixup_silent_linux() written and will send out a patch with just that
> shortly.

Please consider it NAKed.

> Based on your comments, I'll assume that you're not interested in the more
> general command line munging tools and will abandon them for now until there
> is a clear need for them.

"Not interested" is an understatement.  I consider them a highly
unefficient and conceptually broken approach.

Best regards,

Wolfgang Denk

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