Hi Marek,
On 7/7/24 2:29 AM, Marek Vasut wrote:
On 7/1/24 10:42 AM, Quentin Schulz wrote:
Hi Marek,
Hi,
Shouldn't this rather be in /config node?
This is what I had there originally, but then I realized that some
DTs might not have the /config node in them (or am I mistaken?), so
I moved the new properties into the root node, which surely exists.
It also keeps the code simpler, as it doesn't have to fiddle with
creation of the /config node if it doesn't exist.
I don't think we should pollute the root node with this. If we want
to be able to expose this in a proper binding to the upstream DT
binding repo, I'm not sure this is going to fly :/
The other option is to add more code into SPL, that's not great.
I can check if /config node exists, and if so, add it there,
otherwise do nothing. That should be some sort of compromise between
bloat and config node. What do you think ?
[...]
Considering that we're trying to have the same DT for U-Boot and Linux
kernel in the long run and that `git grep "\s+config {"` returns
nothing in dts/upstream/src, I'm not sure this amounts to anything but
dead-code? We could also always insert this node as pre/post process
of the DT compilation? But I think some people want to reuse the exact
same DTB (like, the binary itself) between U-Boot and the Linux kernel.
In my case, the /config node is inserted via *-u-boot.dtsi , I don't
think those DT extras are going away anytime soon, esp. because of the
'bootph-*' properties.
The bootph properties are standardized (?) now. The kernel accepts them
(see the ti and xilinx DTSes for Aarch64 for example) and it's part of
the dt-schema now:
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/bootph.yaml
though I cannot find it in the DT specification (not sure they need to
be there though).
I guess we can start with checking if the /config node exists and we
can figure something smarter once we need it?
[...]
2- Add info about which DTBOs were applied to the kernel DTB?
SPL DTOs or DTOs applied from kernel fitImage ? Or a merging of those ?
DTOs that U-Boot proper applies to the kernel DTB either via fitimage
configs, maybe also via syslinux (via
`fdtoverlays`/`devicetree-overlay`) and the like?
Isn't that something that would be better (=more flexible and fixable if
broken without bootloader update) done in a boot script which could be
embedded in a fitImage ?
That's one way to do it though you risk desynchronization between the
boot script and which overlays are applied and in which order.
Additionally, can we actually already run a boot script from a
configuration node? Because one can simply boot with a fit configuration
and all of its DTBOs will be applied (if I'm not mistaken), if the boot
script needs to be executed standalone before booting the configuration
node, that's quite a surprising workflow (but that would work; we could
probably also have the boot script directly call the bootm command with
the proper configuration node, but then one would have to find a way on
how to select which boot script to use between each representing their
own configuration node?).
Cheers,
Quentin
