From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sebastian Reichel <sre@kernel.org>
Subject: Re: debug tip after earlycon is closed?
Date: Wed, 27 Jul 2016 04:17:49 +0200
Message-ID: <20160727021748.GA9857@earth>
References: <CAK7LNASrqbt+RzD64zcAMjmBjJqa2sc2UG+mnEX8npZ9DBJodQ@mail.gmail.com>
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To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Peter Hurley <peter@hurleysoftware.com>, Rob Herring <robh+dt@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-serial@vger.kernel.org, linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
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Hi,

On Wed, Jul 27, 2016 at 10:23:09AM +0900, Masahiro Yamada wrote:
> When the kernel fails to boot and its log console is silent,
> I use earlycon and I often find the cause of error with it.
>=20
> But, I have been wondering if there is an easy-to-use
> debug tip which is available after earlycon is disabled.
>=20
> I noticed the current mainline would not boot on my ARMv8 board.
> According to the following log, I am guessing something wrong
> is happening after the "bootconsole [uniphier0] disabled" log.
>=20
> Is there a good practice to see more log?

Documentation/kernel-parameters.txt=20
	keep_bootcon	[KNL]
			Do not unregister boot console at start. This is only
			useful for debugging when something happens in the window
			between unregistering the boot console and initializing
			the real console.

-- Sebastian

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