Hi Francois,
On Thu, Dec 19, 2019 at 01:52:29PM +0100, Francois Ozog wrote:
>
> 5. TS: How are we getting on with the separate DT repo?
> a. Hoping to convince people still, hoping the prototype will help
> b. Qualcomm are managing DTs separately with Android, and it's been
> working OK for them for over a year now.
> c. We're keen to make sure we don't annoy Linux people,
> particularly the non-DT users!
>
>
>We'll certainly talk about this in the context of DTE-8.
>As of now, U-Boot 19.10 embedded DTBs generates kernel 5.3 warnings for binding
>obsolescence on some platforms.
That sounds worrying - do you have examples you could share, please?
We've been talking about DT stability, which doesn't sounds like this!
>So, if we think of the DTB provided to Linux as a separate entity, we can split
>the world in two:
>- System Device Tree specs and unified repo agreed upon by platform people.
>- DTB for Linux to be considered as a separate entity in U-Boot (specific
>lifecycle in the specs).
>By doing this split we give time to Linux community to understand and see the
>value of the proposed DTB lifecycle.
So there's two sides of this, and I *think* I understand which one
you're coming from:
1. General-purpose devices designed to be run by end-users with a
range of kernels/systems added/installed/upgraded later. The
platform comes with firmware that (hopefully?) includes working DT
data.
2. Special-purpose devices where the combination of
firmware/kernel/system are more tightly managed together by the
platform vendor.
I'm worried about case 1 here with DTB updates applied later, in that
there's potential for incompatibilities/breakage between the DTB and
the (user-installed) system running on it. How do we get to a good
general-purpose solution here?
>There is still the question of signed DTB in a UEFI Secure Boot environment:
>shall we embed two DTBs in U-Boot or find a way to sign DTBs?
>And then we will be able to properly address the cases where OPTEE is doing
>live adjustments to a signed DTB.
Cheers,
--
Steve McIntyre steve.mcintyre@xxxxxxxxxx
<http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs
