Hi Tom,
On Wed, Dec 27, 2023 at 8:06 PM Tom Rini <tr...@konsulko.com> wrote: > > On Wed, Dec 27, 2023 at 05:48:42PM +0000, Simon Glass wrote: > > Hi Tom, > > > > On Tue, Dec 26, 2023 at 12:07 PM Tom Rini <tr...@konsulko.com> wrote: > > > > > > On Tue, Dec 26, 2023 at 09:46:25AM +0000, Simon Glass wrote: > > > > > > > Standard passage provides for a bloblist to be passed from one firmware > > > > phase to the next. That can be used to pass the devicetree along as > > > > well. > > > > Add an option to support this. > > > > > > > > Tests for this will be added as part of the Universal Payload work. > > > > > > > > Signed-off-by: Simon Glass <s...@chromium.org> > > > > --- > > > > The discussion on this was not resolved and is now important due to the > > > > bloblist series from Raymond. So I am sending it again since I believe > > > > this is a better starting point than building on OF_BOARD > > > > > > I really don't like adding another option for "DT is given to us". Why > > > isn't adding another enum to fdt_source_t sufficient > > > > That is added by this patch, but... > > > > >, and if we have > > > bloblist enabled, that will look for and use if found? > > > > ...this is the question. I would like to be able to enable bloblist > > without *requiring* the DT to come from there, hence the separate > > Kconfig option. > > > > > Maybe some other > > > code needs to be restructured and cleaned up too? > > > > Possibly, but I really am not keen on this board-specific solution. I > > believe Ilias & I agreed that OF_BOARD should fade away, so I don't > > like adding another thing onto it. > > I think you're missing something then. It should not be board specific > to just find the dtb via bloblist, without a new CONFIG. Yes, that is what I am looking for. > Whatever is > stopping that is what needs to be refactored and then you can just > extend fdt_source_t without a new CONFIG option. OK, but I need a way to turn it off, at least for development. [merging in the other thread:] On Wed, Dec 27, 2023 at 8:11 PM Tom Rini <tr...@konsulko.com> wrote: > > On Wed, Dec 27, 2023 at 05:48:44PM +0000, Simon Glass wrote: > > Hi Ilias, > > > > On Wed, Dec 27, 2023 at 6:44 AM Ilias Apalodimas > > <ilias.apalodi...@linaro.org> wrote: > > > > > > Hi Tom, > > > > > > On Tue, 26 Dec 2023 at 14:07, Tom Rini <tr...@konsulko.com> wrote: > > > > > > > > On Tue, Dec 26, 2023 at 09:46:25AM +0000, Simon Glass wrote: > > > > > > > > > Standard passage provides for a bloblist to be passed from one > > > > > firmware > > > > > phase to the next. That can be used to pass the devicetree along as > > > > > well. > > > > > Add an option to support this. > > > > > > > > > > Tests for this will be added as part of the Universal Payload work. > > > > > > > > > > Signed-off-by: Simon Glass <s...@chromium.org> > > > > > --- > > > > > The discussion on this was not resolved and is now important due to > > > > > the > > > > > bloblist series from Raymond. So I am sending it again since I believe > > > > > this is a better starting point than building on OF_BOARD > > > > > > > > I really don't like adding another option for "DT is given to us". Why > > > > isn't adding another enum to fdt_source_t sufficient, and if we have > > > > bloblist enabled, that will look for and use if found? Maybe some other > > > > code needs to be restructured and cleaned up too? > > > > > > Same here. On top of that the bloblist has a few items in there, e.g a > > > TPM eventlog. What are we going to do? Add a Kconfig for each item? > > > > No, but that is just a straw man. The DT is special and U-Boot reports > > where it comes from. > > > > > > > > This has been going back and forth for a while. I've lost count of how > > > many times I repeated the same proposal, but here it goes again. We > > > have OF_BOARD and BLOBLIST options. The bloblist and its properties > > > are scannable at runtime. Can't we use the combination of these 2 can > > > be used to imply we expect things from a bloblist. If we want to be > > > stricter in the future and explicitly expect the DT from a bloblist, > > > we could add a Kconfig option failing the boot if that's missing. > > > > I would like to have that Kconfig option now, not later. In my mind, > > the boot must be deterministic, so that if OF_BLOBLIST is enabled, the > > DT must come from there, or it is an error. > > Determinism doesn't require a CONFIG option, it just requires an if/else > tree where we say what the "correct" priority list should be and then > set a flag so that we can tell the user where we found it too. This also > means that we can get whatever is going to use this mechanism to > migrate over, and have less of a chicken-and-egg type of problem. OK I think I understand what is going on here. We need a way to enable OF_BLOBLIST while still allowing the prior stage to NOT provide a bloblist, at least for a transition period (= forever, I suspect, but that's another discussion). How about if OF_BLOBLIST enables the option, but we allow a fallback to OF_BOARD if the DT is not there? > > > Also, repeating it doesn't make the proposal good. We agreed that > > OF_BOARD would eventually go away, so building on top of it is not > > setting us up for the future. > > I wonder if OF_BOARD will ever go away, and I'm not convinced it will > either. Unless you just mean re-naming it and making a few ad-hoc > standards more easily re-usable, which also will need to happen > regardless. Regards, Simon
