On Thu, Aug 22, 2013 at 11:23 AM, Scott Wood scottwood@freescale.com wrote:
On Thu, 2013-08-22 at 11:15 -0500, Stuart Yoder wrote:
On Mon, Aug 19, 2013 at 2:59 PM, Scott Wood scottwood@freescale.com wrote:
On Fri, 2013-08-16 at 09:14 -0500, Stuart Yoder wrote:
On Thu, Aug 15, 2013 at 8:47 AM, fenghua@phytium.com.cn wrote:
From: David Feng fenghua@phytium.com.cn
This patch provide u-boot with arm64 support. Currently, it works on Foundation Model for armv8 or Fast Model for armv8.
Signed-off-by: David Feng fenghua@phytium.com.cn
Changes for v3: - rewrite cache.S and exception.S that partly originated from linux kernel, so the license should be ok.
board/armltd/dts/vexpress64.dts | 215 ++++++++++++++++++++++++++++++++++
Why is the device tree source in u-boot (instead of in the kernel)? Is this temporary? It looks like this device tree is just a copy from somewhere else.
Would suggest removing this from this patch series and keep the dts maintained in the Linux kernel.
U-Boot itself uses the device tree (not just to patch up for Linux) on some targets.
Even with the way PPC uses device trees, it doesn't really make sense to keep them in the kernel given that they're meant to be OS-neutral, and have ties to U-Boot in terms of what gets fixed up at runtime.
It may not make sense, but that is where they are kept currently.
For PPC.
$ find arch/arm/boot/dts | wc -l 425 $ find arch/powerpc/boot/dts | wc -l 315
There are also a handful of device trees under arch/arm64/boot/dts, including what looks like a vexpress board.
It doesn't make sense to maintain 2 copies of a vexpress64.dts device tree in 2 different places...or to maintain 1 lone device tree in u-boot.
Why does it not make sense for there to be one lone device tree in U-Boot?
It doesn't make sense to me to keep one device tree in u-boot and the rest in the kernel.
I don't know where that vexpress64.dts came from, but I'm guessing it's a copy from the Linux kernel.
A device tree that is not used with U-Boot may not look the same, since U-Boot is (at least on some platforms) responsible for filling in parts of the tree, and (again on some platforms) for setting up the address map.
Maybe we need a git repo for device trees that could be included in Linux, u-boot, and other things a submodule.
Submodules can be a pain. If we don't use them for DTC, why would we use them for this? Since they require extra commands, you'd be modifying the workflow of everyone that builds U-Boot and/or Linux for affected platforms.
You shouldn't need device trees for building u-boot or the kernel. I don't think a couple of extra commands is that burdensome.
I agree the DTS files really don't belong in the kernel, but there is currently no better repository that has been proposed. I'm not sure u-boot is a better place. Device trees should be independent of any particular bootloader or OS.
Stuart