From owner-freebsd-arm@freebsd.org Thu Sep 10 11:32:55 2015 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A9EFEA00F23 for ; Thu, 10 Sep 2015 11:32:55 +0000 (UTC) (envelope-from andrew@fubar.geek.nz) Received: from kif.fubar.geek.nz (kif.fubar.geek.nz [178.62.119.249]) by mx1.freebsd.org (Postfix) with ESMTP id 74DDC1B0B for ; Thu, 10 Sep 2015 11:32:55 +0000 (UTC) (envelope-from andrew@fubar.geek.nz) Received: from bender.Home (bcdc6507.skybroadband.com [188.220.101.7]) by kif.fubar.geek.nz (Postfix) with ESMTPSA id 5FB8DD7F66; Thu, 10 Sep 2015 11:32:53 +0000 (UTC) Date: Thu, 10 Sep 2015 12:32:51 +0100 From: Andrew Turner To: Shannon Zhao Cc: , , linux-efi@vger.kernel.org, ian.campbell@citrix.com, linux-doc@vger.kernel.org, ard.biesheuvel@linaro.org, linux-kernel@vger.kernel.org, leif.lindholm@linaro.org, xen-devel@lists.xen.org, julien.grall@citrix.com, freebsd-arm@freebsd.org, matt.fleming@intel.com, christoffer.dall@linaro.org, jbeulich@suse.com, peter.huangpeng@huawei.com, stefano.stabellini@eu.citrix.com, shannon.zhao@linaro.org Subject: Re: [PATCH] efi/libstub/fdt: Standardize the names of EFI stub parameters Message-ID: <20150910123251.7e0810d1@bender.Home> In-Reply-To: <1441874516-11364-1-git-send-email-zhaoshenglong@huawei.com> References: <1441874516-11364-1-git-send-email-zhaoshenglong@huawei.com> X-Mailer: Claws Mail 3.12.0 (GTK+ 2.24.28; amd64-portbld-freebsd10.1) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Thu, 10 Sep 2015 11:46:14 +0000 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Sep 2015 11:32:55 -0000 On Thu, 10 Sep 2015 16:41:56 +0800 Shannon Zhao wrote: > From: Shannon Zhao > > These EFI stub parameters are used to internal communication between > EFI stub and Linux kernel and EFI stub creates these parameters. But > for Xen on ARM when booting with UEFI, Xen will create a minimal DT > providing these parameters for Dom0 and Dom0 is not only Linux > kernel, but also other OS (such as FreeBSD) which will be used in the > future. So here we plan to standardize the names by dropping the > prefix "linux," and make them common to other OS. Also this will not > break the compatibility since these parameters are used to internal > communication between EFI stub and kernel. It is unlikely FreeBSD will use this property when booting ad Xen dom0. The kernel expects to be passed a data structure to find boot this information. My preference would be to have the FreeBSD loader load the xen binary, the FreeBSD kernel, and set up these data structs before passing control to Xen, with the information it needs to boot the kernel. My understanding is this is how it is done on x86. I can see a few issues with this where, for example, the device tree or ACPI tables need to be modified, but these should be solvable. Andrew