From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [Linaro-uefi] [PATCH] xen: arm: implement generic multiboot compatibility strings (Was: Re: The GRUB multiboot support patch for aarch64(V3.1)) Date: Fri, 06 Jun 2014 14:25:51 +0100 Message-ID: <5391C15F.204@linaro.org> References: <536A1FCF.50207@linaro.org> <1401899819.15729.44.camel@hastur.hellion.org.uk> <5390205B.5060803@linaro.org> <1401969408.15729.52.camel@hastur.hellion.org.uk> <53909CA0.9010407@linaro.org> <1401987331.7269.81.camel@dagon.hellion.org.uk> <5390A2F6.2060305@linaro.org> <1401993081.15729.170.camel@hastur.hellion.org.uk> <5391B2F1.5070307@linaro.org> <5391B3D9.5090901@linaro.org> <1402057973.1313.40.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1402057973.1313.40.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: linaro-uefi , Fu Wei , xen-devel List-Id: xen-devel@lists.xenproject.org On 06/06/2014 01:32 PM, Ian Campbell wrote: > On Fri, 2014-06-06 at 13:28 +0100, Julien Grall wrote: >> On 06/06/2014 01:24 PM, Fu Wei wrote: >>> On 06/06/2014 02:31 AM, Ian Campbell wrote: >>>> On Thu, 2014-06-05 at 18:03 +0100, Julien Grall wrote: >>>>>>> While we are modifying the protocol, "linux-zImage" is confusing in the >>>>>>> name. Actually we can use it for an ELF, another OS... I don't think Xen >>>>>>> will change his behavior depending of the DOM0 image. >>>> >>>> Actually thinking about this some more I think you are right. Xen >>>> already probes the kernel it gets so we can safely implement this as >>>> multiboot,kernel, since we don't really need the more specific type. If >>>> in the future some non-probable kernel comes along which we want to >>>> support we still have the option of adding more specific compatibility >>>> strings. >>>> >>>> Fu Wei -- if this is OK with you I will modify the wiki page to >>>> s/multiboot,linux-zimage/multiboot,kernel/ and rev this patch to suit. >>> >>> This is OK for me, And I think the "multiboot,kernel" is better and more generic. :-) >>> >>>> >>>> Can we do something similar with linux-ramdisk? I'm not sure since we >>>> cannot easily probe the ramdisk contents. We could base the ramdisk >>>> behaviour on the probed behaviour of the kernel. Anyone got any >>>> thoughts? >>> >>> My thought looks exactly the same as yours : >>> The cpio utility can detect the cpio file format. Maybe we can just probe the file, see if this is a cpio or cpio.gz. >> >> cpio is not Linux specific. Probing just the file won't help here to to >> determine if we have to add the properties linux,initrd-* or another set. > > This can/should be determined by probing the type of kernel which the > initrd is being passed to, it is not a property of the initrd. I don't find anything documentation in Linux tree that claim the linux,initrd-* properties is part of the zImage protocol. FYI, the device tree documentation in Linux (Documentation/devicetree/usage-model.txt) is talking about initrd-{start,end}, not linux,initrd-{start,end}. If we plan to assume that the zImage always go with linux,initrd* properties then we have to document this specification somewhere. Regards, -- Julien Grall