Hi Rob,
On Mon, 11 Oct 2021 at 12:36, Rob Herring robh@kernel.org wrote:
On Sun, Oct 3, 2021 at 1:35 PM Mark Kettenis kettenis@openbsd.org wrote:
Add preliminary device trees for the Apple M1 mini (2020) and Apple M1 Macbook Pro 13" (2020). Device tree bindings for the Apple M1 SoC are still being formalized and these device trees will be synchronized with the Linux kernel as needed.
So not synchronized currently? If it is sync'ed, you should specify which version you got.
These device trees are provided as a reference only as U-Boot uses the device tree passed by the m1n1 bootloader.
If reference only, why do they need to be checked in here? We're trying to get to fewer copies both of dtbs at runtime and dts files in source trees.
I mainly bring it up here because this is a platform with multiple OS targets, following the model that DT comes from the firmware, and should be free of schema validation warnings. In other words, it's a good candidate to define best practices.
This is something I have brought in, as U-Boot DT maintainer, to provide some sort of reference in U-Boot as to what is actually built. It allows people to see the devices and also ensures that the build system does build a devicetree. The existing OF_PRIOR_STAGE is being removed and OF_BOARD is becoming a bool, with OF_SEPARATE the standard approach.
We have a few examples where this is not done (e.g. qemu-arm) but I am working on fixing that. It has led to discussions about whether U-Boot is entitled to having its own things in the DT, etc. etc. The whole area is in flux at present. If you want some background:
https://patchwork.ozlabs.org/project/uboot/patch/20210919215111.3830278-3-sj...
Regards, Simon