From mboxrd@z Thu Jan 1 00:00:00 1970 From: zonque@gmail.com (Daniel Mack) Date: Fri, 26 Jul 2013 18:13:08 +0200 Subject: Appended DTB files for multi-machine kernels In-Reply-To: References: <51D5A938.30607@gmail.com> Message-ID: <51F2A014.7000209@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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