From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH RFC 0/N] xen: arm: rework early bring up Date: Wed, 18 Sep 2013 14:40:24 +0100 Message-ID: <5239AD48.9040403@linaro.org> References: <1379381846.11304.73.camel@hastur.hellion.org.uk> <52383E5C.9000704@linaro.org> <1379421810.11304.87.camel@hastur.hellion.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1379421810.11304.87.camel@hastur.hellion.org.uk> 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: Julien Grall , Stefano Stabellini , Tim Deegan , Andre Przywara , xen-devel List-Id: xen-devel@lists.xenproject.org On 09/17/2013 01:43 PM, Ian Campbell wrote: > On Tue, 2013-09-17 at 12:34 +0100, Julien Grall wrote: >> Adding Andre, > > Thanks, I meant to and forgot... > >> On 09/17/2013 02:37 AM, Ian Campbell wrote: >>> Hi, >> >> Hi, >> >>> The following reworks early bring up on ARM to use a separate set of >>> boot pagetables. This simplifies things by avoiding the need to bring up >>> all CPUs in lock step, which in turn allows us to do secondary CPU >>> bringup in C code. >> >> Great ! I will give a try on different boards and see what happens. > > Thanks. > >>> Unfortunately the main bulk of this change is a single large patch which >>> is hard to decompose any further since it is basically pulling on the >>> thread and then knitting a new jumper from it. >> >> I think you can split the patch in: >> - Add the new platform callback >> - Fast model SMP code >> - ... >> >> We will have dead code for "few" commit in Xen, but it will be easier to >> read the patch series :). > > yes, that's a good idea. The main patch will still be massive though. > >>> With these changes Xen now absolutely requires that the bootloader calls >>> the hypervisor in HYP mode, the previous workarounds have been removed. >>> For use on models a bootwrapper is now required. See >>> git://xenbits.xen.org/people/ianc/boot-wrapper.git xen-arm32 >>> git://xenbits.xen.org/people/ianc/boot-wrapper-aarch64.git xen-arm64 >>> >>> I have implemented support for CPU bringup on the fastmodel vexpress >>> platforms (v7and v8) here, I suppose it should work OK on a real >>> vexpress too but I've not tried it. >> >> Unfortunately on the versatile express there is 2 different ways to >> bring up CPUs. >> We can stick to this CPU bring up, as long as we ask the user to modify >> the board configuration. > > Is it possible to determine programaticaly which method to use? It seems no, I will take a closer look. > In any case this series isn't changing anything in this regard, so we > must already be asking users to modify the boards configuration. -- Julien Grall