From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 0/8] Generic serial earlycon
Date: Sun, 23 Mar 2014 20:49:41 +0100 [thread overview]
Message-ID: <201403232049.41866.arnd@arndb.de> (raw)
In-Reply-To: <CAL_Jsq+j4ixVbfue62q_tOHb-HPA2jAxwZtTjtLy6jE9crGvsg@mail.gmail.com>
On Sunday 23 March 2014, Rob Herring wrote:
> IIRC, the unflattening cannot be done before memblock is up which is
> in arm_memblock_init. I believe that will get done earlier similar to
> PPC with Laura's meminfo removal series. However, in interest of
> getting output enabled as early as possible, the earliest point is
> always going to be with a flat tree. So I think we do want to be able
> to parse the flat tree for this. There's code in u-boot to do the
> address translation on FDT we can steal. Really, i'd like to put that
> code in libfdt, but there's a licensing problem with the u-boot code
> being GPL and libfdt being BSD.
I suppose it depends on what the goal is. If you are trying to get as
close as possible to the debug_ll functionality without losing the
ability to turn it on unconditionally, I agree that it needs to be done
on the flat tree.
However, the goal that interests me more at the moment is to have
reliable debug output done in a simple way earlier than what we have
today with the normal console support. For this, it seems a better
tradeoff to initialize the early console slightly later. This
can actually be done independent of the the command line option,
I don't see any downsides from having a compile-time option that
would initialize the early console from setup_arch (after
unflatten_device_tree) whenever there is a linux,stdout-path
property that points to a usable device.
Arnd
next prev parent reply other threads:[~2014-03-23 19:49 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-21 21:08 [PATCH 0/8] Generic serial earlycon Rob Herring
[not found] ` < 201403221054.39799.arnd@arndb.de>
[not found] ` < CAL_JsqKjGjyYypwneCmNc1qeKe0ZOG9gz3QSJ37-HwHXKu3iRA@mail.gmail.com>
[not found] ` < 20140329001732.BECE2C41FF4@trevor.secretlab.ca>
2014-03-21 21:08 ` [PATCH 1/8] x86: move FIX_EARLYCON_MEM kconfig into x86 Rob Herring
2014-03-21 21:08 ` [PATCH 2/8] arm64: add FIXMAP_PAGE_NOCACHE definition Rob Herring
2014-03-24 11:13 ` Catalin Marinas
2014-03-21 21:08 ` [PATCH 3/8] arm64: enable FIX_EARLYCON_MEM kconfig Rob Herring
2014-03-24 11:38 ` Catalin Marinas
2014-03-21 21:08 ` [PATCH 4/8] tty/serial: add generic serial earlycon Rob Herring
2014-03-24 11:22 ` Catalin Marinas
2014-03-24 11:29 ` Arnd Bergmann
2014-03-24 13:36 ` Rob Herring
2014-03-24 15:42 ` Arnd Bergmann
2014-04-17 18:27 ` Rob Herring
2014-04-17 20:16 ` Alan Cox
2014-04-19 11:32 ` Arnd Bergmann
2014-03-21 21:08 ` [PATCH 5/8] tty/serial: convert 8250 to generic earlycon Rob Herring
2014-03-21 21:08 ` [PATCH 6/8] tty/serial: pl011: add generic earlycon support Rob Herring
2014-03-24 11:28 ` Catalin Marinas
2014-04-16 22:14 ` Rob Herring
2014-04-23 16:39 ` Catalin Marinas
2014-03-21 21:08 ` [PATCH 7/8] tty/serial: add arm64 semihosting earlycon Rob Herring
2014-03-23 20:04 ` Nicolas Pitre
2014-03-23 20:23 ` Arnd Bergmann
2014-03-23 21:48 ` Nicolas Pitre
2014-03-24 11:38 ` Catalin Marinas
2014-03-24 11:48 ` Catalin Marinas
2014-03-21 21:08 ` [PATCH 8/8] arm64: remove arch specific earlyprintk Rob Herring
2014-03-22 9:54 ` [PATCH 0/8] Generic serial earlycon Arnd Bergmann
2014-03-22 14:14 ` Rob Herring
2014-03-22 22:01 ` Arnd Bergmann
2014-03-23 15:09 ` Rob Herring
2014-03-23 19:49 ` Arnd Bergmann [this message]
2014-03-29 0:17 ` Grant Likely
2014-03-29 14:33 ` Rob Herring
2014-03-29 15:34 ` Grant Likely
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