From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id E0E0DE00723 for ; Thu, 5 Apr 2012 16:46:27 -0700 (PDT) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 05 Apr 2012 16:46:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="150176119" Received: from unknown (HELO envy.home) ([10.255.12.143]) by fmsmga002.fm.intel.com with ESMTP; 05 Apr 2012 16:46:27 -0700 Message-ID: <4F7E2EAB.7080900@linux.intel.com> Date: Thu, 05 Apr 2012 16:45:47 -0700 From: Darren Hart User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: Denys Dmytriyenko References: <30B122B8-C6E4-46CE-87A9-AF7F61A06643@keylevel.com> <4F7DFC36.5040108@mlbassoc.com> <8E003040-BCBA-43ED-82B3-9C7BF771AB44@keylevel.com> <20120405210547.GC11087@denix.org> In-Reply-To: <20120405210547.GC11087@denix.org> X-Enigmail-Version: 1.4 Cc: yocto@yoctoproject.org Subject: Re: kernel26 'machine feature' X-BeenThere: yocto@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of all things Yocto List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Apr 2012 23:46:28 -0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit On 04/05/2012 02:05 PM, Denys Dmytriyenko wrote: > On Thu, Apr 05, 2012 at 09:17:28PM +0100, Chris Tapp wrote: >> On 5 Apr 2012, at 21:10, Gary Thomas wrote: >> >>> On 2012-04-05 14:02, Chris Tapp wrote: >>>> Quite a few machine conf files specify the kernel26 machine feature. e.g., crownbay.conf has: >>>> >>>> MACHINE_FEATURES = "kernel26 screen keyboard pci usbhost ext2 ext3 x86 \ >>>> acpi serial usbgadget" >>>> >>>> What does this do? It's not listed at http://www.yoctoproject.org/docs/latest/poky-ref-manual/poky-ref-manual.html#ref-features-machine and seems to be at odds with: >>>> >>>> PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" >>>> PREFERRED_VERSION_linux-yocto = "3.0%" >>> >>> I don't think it does anything any more. I'm pretty sure it used >>> to be used to select which style of kernel module utilities to >>> install (there was a change in kernel module format between 2.4 >>> and 2.6), but it seems that's gone now. At least in the Poky/Yocto >>> tree (oe-core + meta-yocto), there is no active use of this feature. > > Yes, Classic OE (unlike OE-Core) used to support 2.4 and 2.6 kernels, hence > the use flag. > >> Thanks, I was hoping it was something as simple as that. >> >> Another (possibly related) question - when the kernel built I noticed that >> linux_libc_headers_yocto-2.6.37 was 'mentioned' in the log output. Why was >> this used and not the headers for 3.0.18 ? The host is 2.6.32, so it doesn't >> look like is was for the tool chain. > > Those are "user-space" kernel headers for libc. Those usually don't need to > match the exact kernel version, as APIs don't change that often between the > kernel and user-space. Unless you need some specific new API that got added in > the latest kernel... > It's done this way to speed the build process as it uses a simple tarball download of the kernel sources to do this. Ultimately I believe we should build this package as part of the kernel build and PROVIDE it as well. -- Darren Hart Intel Open Source Technology Center Yocto Project - Linux Kernel