From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by mx1.pokylinux.org (Postfix) with ESMTP id B1D044C80BCF for ; Tue, 14 Dec 2010 14:59:42 -0600 (CST) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 14 Dec 2010 12:59:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,344,1288594800"; d="scan'208";a="583720421" Received: from doubt.jf.intel.com (HELO [10.7.199.80]) ([10.7.199.80]) by orsmga002.jf.intel.com with ESMTP; 14 Dec 2010 12:59:39 -0800 Message-ID: <4D07DAB8.3030504@linux.intel.com> Date: Tue, 14 Dec 2010 12:59:36 -0800 From: Darren Hart User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: "poky@yoctoproject.org" Subject: kernel type selection X-BeenThere: poky@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Poky build system developer discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Dec 2010 20:59:42 -0000 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In developing new kernel recipes, I've run across some difficulty in determining the ideal way to select one kernel recipe over another. The machine configs specify the preferred provider. For the Linaro layer, I setup new machine configs which specified the linux-linaro as the preferred kernel. As I'm working with preempt_rt, I'm running into this again. I could create more machine configs, but this approach won't scale well (having to create a copy of all the supported machine configs just to change the preferred kernel). I could set LINUX_KERNEL_TYPE="preempt_rt" in my local.conf, but that would reuse all the settings in the existing recipes (like COMPATIBLE_MACHINES), all of which don't necessary apply to the new kernel type. I've considered looking for a way to specify the kernel type in the new image definitions (ie poky-image-rt) and creating new recipes for each kernel type. I like the idea of one recipe per kernel type as this makes things more explicit and avoids contamination between the various kernel types. This approach however seems to be at odds with the Poky way of doing this which, as I understand it, would be to specify the provider in the machine config and any modifiers (like type) in the local.conf. Can we get a discussion started here to determine some best practices? Thanks, -- Darren Hart Yocto Linux Kernel