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  • Oct 5, 2026, 1:09 PM

    @cas @elly There has been interest in moving DT out of Linux for many years. It hasn't happened yet and I doubt it will anytime soon.

    To support completely new hardware, you have to write the definition almost entirely from scratch. The reason we don't have to do that with ACPI is because it's not really allowed to do OS-provided ACPI definitions (that was an APM thing and it was a bad idea).

    I'm saying that DT is way more work, and hardware support over the long term is much harder.

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  • Oct 5, 2026, 1:34 PM

    @neal @elly we'll have to agree to disagree. my experience working with devicetree has only reconfirmed the reasons it was adopted in the first place -- it's a very simple concept. in 2026 a lot of the earlier architectural issues have been figured out. Bringing up a new platform is not that bad actually??

    we also are in a much better place to write DT in a way that allows us to make backwards compatible changes as we describe the hardware in more detail. with ACPI you're just screwed when sayyy a vendor doesn't bother to model your type-c port as dual role capable even though it is, you lose out on hardware features that your device actually has!

    nevermind the hellish issues with EC quirks and all the driver workarounds that are needed due to bad firmware

    it's perfectly fine to have a preference here but i don't buy this "it's so much harder" line especially from someone who afaik hasn't had to do bring up or long term development on DT platforms. I'd take it any day over ACPI if it means not having to deal with a fw blob of unknown quality that might have deranged bugs

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  • Oct 5, 2026, 1:57 PM

    @neal @cas @elly Are you talking about moving the DTS files out of Linux kernel repo, or something else?

    DT used correctly belongs in the bootloader firmware of the board passed to the kernel by the bootloader, with the possibility to patch it there if needed to fix bugs or under-expressiveness in how it shipped. The Linux folks' idea of shipping DT stuff alongside the kernel is totally missing the point.

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  • Oct 5, 2026, 4:39 PM
    @neal @dalias @elly @cas Well EDKII, at least on Honeycomb LX2K, has a toggle between ACPI and DeviceTree.

    And IIRC (noticed a bad ram address it something like 6 months ago, haven't booted it since) in-spi u-boot on the VisionFive2 also provides it's DeviceTree to the kernel.

    And I guess on RockPro64 where you can have in-spi u-boot, it could be provided in the same way if not already the case (as there's even the tow-boot project providing pre-built u-boot images to be flashed).
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