Ok, back and forth compatibility ... we have had this discussion internally a few times already and this is difficult one to fix if there's a fix. An OS DTB could break platform-OS interoperability, if not limited, that's why this thread caught my eye 😊
I would say that to preserve the interoperability between platforms and OSes, the DT must sit wherever the data being represented belongs. If data structure (DT in this case) is relative to platform then it belongs within the platform FW, if data presented is relative to the OS then it belongs within the OS. I would say the OS DTB is a point-to-point solution potentially breaking the interoperability principles, and opening Pandora's box ... Perhaps a better approach would be for the OSVs to provide a DT overlay to fix specific OS compatibilities, thus maintaining interoperability without compromising the underlying principles. A FW DT always must exist to enable interoperability and an optional OS DTB overlay would be allowed to help addressing backwards compatibility but just as an overlay on top of the FW one. As said, this just caught my eye but definitely a good topic for discussion within the EBBR forum ... BR Pere -----Original Message----- From: Marcin Juszkiewicz <marcin.juszkiew...@linaro.org> Sent: Thursday, May 2, 2024 10:09 AM To: boot-architecture@lists.linaro.org Subject: Re: OS provided DT proposal W dniu 2.05.2024 o 09:18, Pere Garcia pisze: > SystemReady IR owner here at ATG. SystemReady SR fan here. > May I ask, what would be the purpose of DTB provided by the OS? The > primary function (not only one) of DTB from a SystemReady perspective > is for the Platform (fw) advertise to the OS what's in there, there > are other secondary functions and some vendors use DTB to store > FW-only information or proprietary data structures that do not break > the interoperability to OSes. Is such OS DTB containing platform > information, or is this DTB containing data useful for the OS or > meaningful to be originated from the OS ? can you please elaborate a > bit? VendorX releases DeviceY in 2024 with DTB working with Linux 6.6, OpenBSD 7.5 versions. During next year goes out of business and updates for DeviceY stop. Two years later some small fix to DT is needed to get it working properly with some OS. Users are left with options: - make own firmware updates to put fixed DT in firmware - use DT overlays - use OS provided DTB 3rd option is the easiest to go. _______________________________________________ boot-architecture mailing list -- boot-architecture@lists.linaro.org To unsubscribe send an email to boot-architecture-le...@lists.linaro.org IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. _______________________________________________ boot-architecture mailing list -- boot-architecture@lists.linaro.org To unsubscribe send an email to boot-architecture-le...@lists.linaro.org
