From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Wed, 11 Dec 2013 17:09:03 +0000 Subject: [PATCH 3/6] arm64: dts: Add a devicetree for the ARMv8 4xA53 4xA57 FVP In-Reply-To: References: <1386767606-6391-1-git-send-email-broonie@kernel.org> <1386767606-6391-3-git-send-email-broonie@kernel.org> <20131211135536.GC17681@e106331-lin.cambridge.arm.com> <20131211141148.GV11468@sirena.org.uk> <20131211150433.GD17681@e106331-lin.cambridge.arm.com> <1386778133.3447.6.camel@linaro1.home> Message-ID: <20131211170903.GF17681@e106331-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Dec 11, 2013 at 04:41:32PM +0000, Ryan Harkin wrote: > On 11 December 2013 16:08, Jon Medhurst (Tixy) wrote: > > On Wed, 2013-12-11 at 15:04 +0000, Mark Rutland wrote: > >> On Wed, Dec 11, 2013 at 02:11:48PM +0000, Mark Brown wrote: > >> > On Wed, Dec 11, 2013 at 01:55:36PM +0000, Mark Rutland wrote: > >> > > On Wed, Dec 11, 2013 at 01:13:23PM +0000, Mark Brown wrote: > > [...] > >> > > >> > > > +/ { > >> > > > + model = "FVP Base"; > >> > > >> > > FVP Base (is as the name implies) a base upon which particular model > >> > > instances are built. This name should be clarified (e.g. "FVP Base A57x4 > >> > > A53x4"). > >> > > >> > > That also applies to the filename. > > This same file is used to boot the AEMv8 architectural model as well > as the Cortex A57-A73 model, so I think someone would need to find > another filename that makes sense in both contexts. > > I guess that using the same file for two models could in itself be a > problem solved via includes and simpler wrappers. We should have a base platform dtsi that describes the standard devices and memory map. Individual variants can include the dtsi and describe the model name and compatible string, CPUs, variant-specific devices, and firmware details. While the same DT will work regardless of cpu type currently, it's relatively easy to factor that out anyway. > > But as Mark Brown says, ARM have originated this file and personally > I'd rather it was changed in the ARM Trusted Firmware repo first and > propagated here. I completely agree that the DTs in the Trusted Firmware repo should be corrected. I will try to get them fixed. > > To answer another question from earlier: there is no direct > correlation between the ARM Trusted Firmware and the device tree files > other than the same repo hosts both files. Trusted firmware does not > build or embed the DTBs. UEFI is currently what loads the DTB and > passes it to the kernel. And that isn't part of the trusted firmware > repo, of course. There _is_ a direct correlation between the trusted firmware and the DT; the psci node describes the Trusted Firmware PSCI implementation. If you don't use the Trusted Firmware then you need a different DT. However, this would only be a platform variant built atop of the more common FVP Base, so most of the DT can be shared. Thanks, Mark.