Hi Raymond, On Mon, 4 Dec 2023 at 12:25, Raymond Mao <raymond....@linaro.org> wrote: > > Hi Simon, > > When `OF_BOARD` is defined, the FDT should be from one of the board-specific > mechanisms: > 1. FDT from a bloblist via boot args > 2. FDT in memory > I don't think we need a new build option to distinguish these two, since it > can be done in runtime by checking whether the boot args follow the FW > Handoff spec conventions and the FDT exists in the bloblist.
No, I would really like this to be deterministic, so we can fail if something goes wrong. The bloblist should be 'declared' as the way to boot, for a board. If in the future all boards a reusing bloblist for this feature, then sure, we can drop it. But we have things like rpi which do their own thing. > If it fulfills the above conditions, we can take the FDT from bloblist, > otherwise from the predefined memory address. > This is fully backward compatible without adding a new build option. Again, we need to obtain the FDT from the bloblist if and only if the board requires it. It creates a lot of confusion to have it as an optional feature, when we know which way it should be. Ultimately OF_BOARD should go away. We just need to push bloblist to other projects and closed-source firmware as the correct way to pass a DT. Regards, Simon [.]
