From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.243]) by ozlabs.org (Postfix) with ESMTP id 4EA17DDE0F for ; Wed, 26 Nov 2008 08:14:43 +1100 (EST) Received: by an-out-0708.google.com with SMTP id d11so93303and.39 for ; Tue, 25 Nov 2008 13:14:42 -0800 (PST) Message-ID: Date: Tue, 25 Nov 2008 15:14:41 -0600 From: "Matt Sealey" To: "Wolfgang Denk" Subject: Re: [PATCH/RFC] Add Alternative Log Buffer Support for printk Messages In-Reply-To: <20081125210502.92402834B020@gemini.denx.de> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_17422_1227311.1227647681876" References: <20081125135519.038abf23@zod.rchland.ibm.com> <20081125210502.92402834B020@gemini.denx.de> Cc: linuxppc-dev@ozlabs.org, Stefan Roese , Grant Erickson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ------=_Part_17422_1227311.1227647681876 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline On Tue, Nov 25, 2008 at 3:05 PM, Wolfgang Denk wrote: > Dear Matt, > > In message > you wrote: > > > > There is also no reason you can't hard-code the locations into the device > > tree, to support older U-Boots that don't know about > > /chosen/linux,log-metadata and /chosen/linux,log-buffer*. > > Actually there is such reason - U-Boot traditionally allocates the log > buffer close to the upper end of system memory, so the start address > depends on the memory size on the board, which may vary. > I think I covered that in "I can think of a bunch of reasons why it's a good idea.. " - but the current implementation is hardcoded in the kernel so there is no problem with *certain* boards having it done this way, and that information being moved from the kernel into a static entry in a device tree. -- Matt Sealey Genesi, Manager, Developer Relations ------=_Part_17422_1227311.1227647681876 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline

On Tue, Nov 25, 2008 at 3:05 PM, Wolfgang Denk <wd@denx.de> wrote:
Dear Matt,

In message <b5e2fc790811251131g63ea9444x57ec0829ca0b069e@mail.gmail.com> you wrote:
>
> There is also no reason you can't hard-code the locations into the device
> tree, to support older U-Boots that don't know about
> /chosen/linux,log-metadata and /chosen/linux,log-buffer*.

Actually there is such reason - U-Boot traditionally allocates the log
buffer close to the upper end of system memory, so the start address
depends on the memory size on the board, which may vary.


I think I covered that in "I can think of a bunch of reasons why it's a good idea.. " - but the current implementation is hardcoded in the kernel so there is no problem with *certain* boards having it done this way, and that information being moved from the kernel into a static entry in a device tree.
 
--
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations
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