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From: zonque@gmail.com (Daniel Mack)
To: linux-arm-kernel@lists.infradead.org
Subject: Appended DTB files for multi-machine kernels
Date: Fri, 26 Jul 2013 18:13:08 +0200	[thread overview]
Message-ID: <51F2A014.7000209@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1307041322070.18597@syhkavp.arg>

On 04.07.2013 19:28, Nicolas Pitre wrote:
> On Thu, 4 Jul 2013, Daniel Mack wrote:
>> In short, devices that have been deployed in quantities come in three
>> hardware variants, which all boot with a unique machine-id. We ship
>> kernel images that have board support for all three machine types, and
>> do minor fixups to platform data of some drivers at runtime, depending
>> on the board revision number (passed in via ATAGs).
>>

> What you describe above more or less fits the definition of what I 
> called the "impedance matcher".  However it doesn't need to be part of 
> the kernel at all.  But you should make it into a separate binary.
> 
> Please have a look at the bottom of this post for a more comprehensive 
> description: http://article.gmane.org/gmane.linux.ports.arm.kernel/242929

FWIW, I gave that approach a try today for a PXA based hardware
platform, and in fact it seems to work very well. Thanks again for
sharing the idea.

In case anyone is interested, the repository is here:

  https://github.com/zonque/pxa-impedance-matcher

As the README says, it's completely specific to my use case, but maybe
anyone can use the code base to spin a different version for a different
board.


Daniel

  parent reply	other threads:[~2013-07-26 16:13 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-04 16:56 Appended DTB files for multi-machine kernels Daniel Mack
2013-07-04 17:11 ` Mark Brown
2013-07-04 21:34   ` Arnd Bergmann
2013-07-04 23:02     ` Daniel Mack
2013-07-05  8:32     ` Magnus Damm
2013-07-04 17:28 ` Nicolas Pitre
2013-07-04 17:57   ` Daniel Mack
2013-07-04 18:27     ` Nicolas Pitre
2013-07-26 16:13   ` Daniel Mack [this message]
2013-07-26 16:44     ` Nicolas Pitre
2013-07-29 21:23     ` [RFC PATCH 0/2] impedance-matcher generic improvements Jason Cooper
2013-07-29 21:24       ` [PATCH 1/2] add cscope Makefile target Jason Cooper
2013-07-29 21:24       ` [RFC PATCH 2/2] WIP: Get kernel and dtb addresses from command line Jason Cooper
2013-07-30  7:48       ` [RFC PATCH 0/2] impedance-matcher generic improvements Daniel Mack
2013-07-30 13:17         ` Jason Cooper
2013-07-30 13:37           ` Daniel Mack
2013-07-30 14:42             ` Jason Cooper
2013-08-02 15:51     ` [RFC PATCH V2 0/9] " Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 1/9] add cscope Makefile target Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 2/9] separate common functions from board specific Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 3/9] rename board.c to board-raumfeld.c Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 4/9] s/.name/.compatible/ Jason Cooper
2013-08-02 21:52         ` Stephen Warren
2013-08-03 14:07           ` Jason Cooper
2013-08-03 14:16             ` Daniel Mack
2013-08-02 15:51       ` [RFC PATCH V2 5/9] directly include needed headers Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 6/9] serial: split out 8250 code, configurable reg addr Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 7/9] add generic board code Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 8/9] make appending images/dtbs optional Jason Cooper
2013-08-02 15:51       ` [RFC PATCH V2 9/9] appended dtbs works! Jason Cooper
2013-08-02 19:42         ` Nicolas Pitre
2013-08-02 19:54           ` Jason Cooper
2013-08-02 19:57           ` Jason Cooper
2013-08-02 17:53       ` [RFC PATCH V2 0/9] impedance-matcher generic improvements Daniel Mack
2013-08-02 18:43         ` Jason Cooper
2013-08-02 18:46           ` Daniel Mack
2013-07-04 18:36 ` Appended DTB files for multi-machine kernels Dirk Behme
2013-07-05 18:36 ` Stephen Warren

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