Re: [PATCH] arm: dt: Initialize boot_command_line from CONFIG_CMDLINE in case DT does not provide /chosen/bootargs

From: "Pali Rohár" <pali.rohar@gmail.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>,
	"Russell King - ARM Linux" <linux@armlinux.org.uk>,
	Arnd Bergmann <arnd@arndb.de>,
	Robin Murphy <robin.murphy@arm.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Ben Dooks <ben-linux@fluff.org>,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>,
	Sebastian Reichel <sre@kernel.org>,
	Aaro Koskinen <aaro.koskinen@iki.fi>, Pavel Machek <pavel@ucw.cz>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm: dt: Initialize boot_command_line from CONFIG_CMDLINE in case DT does not provide /chosen/bootargs
Date: Fri, 16 Dec 2016 17:13:46 +0100	[thread overview]
Message-ID: <201612161713.46770@pali> (raw)
In-Reply-To: <20161216154029.GF4920@atomide.com>

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On Friday 16 December 2016 16:40:30 Tony Lindgren wrote:
> * Javier Martinez Canillas <javier@osg.samsung.com> [161216 04:54]:
> > On 12/16/2016 09:48 AM, Pali Rohár wrote:
> > >>> saying that it cause problems which need to be properly fixed.
> > >>> And if fixing them is harder and will take more time, then
> > >>> correct option is to revert 008a2ebcd677 due to breaking
> > >>> support for more devices.
> > >> 
> > >> If you think that others boards may have the same issue, then
> > >> you could add an empty chosen node to omap3.dtsi. As I said I
> > >> think that in practice this will only be needed for the
> > >> machines using NOLO but you are right that in theory you could
> > >> boot them using other bootloaders and having an empty node
> > >> doesn't cause any harm anyway.
> > > 
> > > Should not be it part of any arm board? IIRC ATAG support is (or
> > > was) not omap3 specified.
> > 
> > Yes, but you were talking about commit 008a2ebcd677 which only
> > removed skeleton.dtsi usage for OMAP3 boards. The same can be done
> > for other SoCs in its top level dtsi for the SoC family of course.
> 
> Yeah probaby best to add the empty chosen node to the ones that had
> skeleton.dtsi removed.

Ok. But still I think that it should be added globally to all arm board 
which can be booted by ATAG bootloader.

> And I think the code should print a warning if no chosen node is
> found?

Which code? Decompressor? Yes, it should but I do not know if at that 
time is (serial) console usable...

-- 
Pali Rohár
pali.rohar@gmail.com

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