[resend from correct email this time.]
All,
On yesterday's call we brainstormed about what topics we want to talk
about on this call going forward. We also said we will continue with
the bi-weekly cadence for a few meetings and then reassess if we should
go monthly instead.
Attending:
* Loic
* Mark
* Etienne
* Arnaud
* Rob
* Ilias
* Bill
* Joakim
Here is the topic list in no specific order:
* New DT format
* Overlays in kernel
* overlays for PCI or USB devices (in an ACPI based system)
* DT for other OSes
* Zephyr DT schema conformance
* ABI stability & testing
* source code sync
* U-boot DT handling
We discussed the ABI issue a bit:
Rob: SystemReady IR 2.0 requires schema conformance
* There are still open questions
+ what version of schema
+ how many warnings allowed
* discussion mostly inside ARM
* 2.0 will come out this fall
Bill: But you can have two DTBs that full conform to schema and are
still ABI breaking
* Example: ST moving from direct kernel Power/clk control to SCMI
* Current recommendation from this group is make new kernels work both
ways until all firmware will have been updated
* The switch over time could be a couple of years for a GP platform.
Loic: It is very difficult to make a kernel that works both ways
* Not all customers see the benefit, (mostly security)
* Some want to keep doing things the old way
Bill: Even if everyone agrees to switch the transition period is hard to
handle in anything except a vertical OS.
We discussed recent status of U-boot DT handling a bit but need a more
structured discussion / investigation.
Bill
--
Bill Mills
Principal Technical Consultant, Linaro
+1-240-643-0836
TZ: US Eastern
Work Schedule: Tues/Wed/Thur
All,
This is to confirm that we will have a meeting today at 2pm UTC, 10 am
US Eastern, which is about 30 min from now.
It has been a good number of months since we meet.
I want to collect topics and we can catch up on what has been happening.
Thanks,
Bill
--
Bill Mills
Principal Technical Consultant, Linaro
+1-240-643-0836
TZ: US Eastern
Work Schedule: Tues/Wed/Thur
Hi,
Here is a quick follow up to our last EBBR call[1] and the discussion we had on
the DT fixup protocol[2].
After consulting with Samer (in Cc:), he has suggested that submitting an ECR to
the UEFI forum would be the way to go. There is a specific template for that,
but Samer is experienced in the process and has kindly offered to help.
Heinrich, would you be ok to work with Samer on an ECR, please?
Best regards,
Vincent Stehlé
System Architect - Arm
[1]: https://github.com/ARM-software/ebbr/wiki/EBBR-Notes-2022.09.26
[2]: https://github.com/ARM-software/ebbr/issues/68
Hi,
I hope everybody had a nice summer.
Could we please resume the EBBR bi-weekly calls?
Let us have our next call on Sep. 26.
Here is the list of proposed topics:
- EFI_CONFORMANCE_PROFILE_TABLE
- EFI_DT_FIXUP_PROTOCOL
- ESRT
- Authenticated capsules
- Bump UEFI specification version to 2.10
This is also captured on the wiki[1] with links. Feel free to add topics.
I would also like to take this opportunity to thank Grant for his work on EBBR.
Best regards,
Vincent Stehlé
System Architect - Arm
[1]: https://github.com/ARM-software/ebbr/wiki/EBBR-Meetings
Hi Varun,
The intent is for the proposed location (a new repository hosted in tf.org) to be used to review proposed changes to this spec.
The details of the contribution and review process will be debated in the ML once we reach consensus on the hosting location.
Regards,
Jose
> -----Original Message-----
> From: Varun Wadekar <vwadekar(a)nvidia.com>
> Sent: 06 July 2022 12:58
> To: Jose Marinho <Jose.Marinho(a)arm.com>; Simon Glass
> <sjg(a)chromium.org>; Rob Herring <robh(a)kernel.org>
> Cc: tf-a(a)lists.trustedfirmware.org; u-boot(a)lists.denx.de; boot-
> architecture(a)lists.linaro.org; François Ozog <francois.ozog(a)linaro.org>;
> Manish Pandey2 <Manish.Pandey2(a)arm.com>; Joanna Farley
> <Joanna.Farley(a)arm.com>; Ilias Apalodimas <ilias.apalodimas(a)linaro.org>;
> Matteo Carlini <Matteo.Carlini(a)arm.com>; Dan Handley
> <Dan.Handley(a)arm.com>; Harb Abdulhamid
> (harb(a)amperecomputing.com) <harb(a)amperecomputing.com>; Samer El-
> Haj-Mahmoud <Samer.El-Haj-Mahmoud(a)arm.com>; nd <nd(a)arm.com>
> Subject: RE: [RFC] Proposed location to host the firmware handoff
> specification.
>
> Hi,
>
> My concern with a standalone gitlab project is that it might be treated as an
> experiment by the wider community and be neglected. Do we have any
> gitlab projects (tf.org or otherwise) that have some "official" value?
>
> @Jose, do you see the location getting used for all future spec reviews? If
> yes, then the gitlab project will acquire some legitimacy over time and we can
> start with it now. But if we see this as a one off, then I would prefer the spec
> being hosted on tf.org.
>
> For the actual mechanics, I prefer reviewing docs and later updates as
> fragments instead of looking at the file and a separate changelog. So a
> platform (gerrit, gitlab, etc) that facilitates the approach would be helpful
> IMO.
>
> -Varun
>
> -----Original Message-----
> From: Jose Marinho via TF-A <tf-a(a)lists.trustedfirmware.org>
> Sent: Wednesday, 6 July 2022 11:50 AM
> To: Simon Glass <sjg(a)chromium.org>; Rob Herring <robh(a)kernel.org>
> Cc: tf-a(a)lists.trustedfirmware.org; u-boot(a)lists.denx.de; boot-
> architecture(a)lists.linaro.org; François Ozog <francois.ozog(a)linaro.org>;
> Manish Pandey2 <Manish.Pandey2(a)arm.com>; Joanna Farley
> <Joanna.Farley(a)arm.com>; Ilias Apalodimas <ilias.apalodimas(a)linaro.org>;
> Matteo Carlini <Matteo.Carlini(a)arm.com>; Dan Handley
> <Dan.Handley(a)arm.com>; Harb Abdulhamid
> (harb(a)amperecomputing.com) <harb(a)amperecomputing.com>; Samer El-
> Haj-Mahmoud <Samer.El-Haj-Mahmoud(a)arm.com>; nd <nd(a)arm.com>
> Subject: [TF-A] Re: [RFC] Proposed location to host the firmware handoff
> specification.
>
> External email: Use caution opening links or attachments
>
>
> Hi All,
>
> > -----Original Message-----
> > From: Simon Glass <sjg(a)chromium.org>
> > Sent: 06 July 2022 09:34
> > To: Rob Herring <robh(a)kernel.org>
> > Cc: Jose Marinho <Jose.Marinho(a)arm.com>;
> > tf-a(a)lists.trustedfirmware.org; u-boot(a)lists.denx.de;
> > boot-architecture(a)lists.linaro.org; François Ozog
> > <francois.ozog(a)linaro.org>; Manish Pandey2
> <Manish.Pandey2(a)arm.com>;
> > Joanna Farley <Joanna.Farley(a)arm.com>; Ilias Apalodimas
> > <ilias.apalodimas(a)linaro.org>; Matteo Carlini
> > <Matteo.Carlini(a)arm.com>; Dan Handley <Dan.Handley(a)arm.com>; Harb
> > Abdulhamid
> > (harb(a)amperecomputing.com) <harb(a)amperecomputing.com>; Samer
> El-
> > Haj-Mahmoud <Samer.El-Haj-Mahmoud(a)arm.com>; nd <nd(a)arm.com>
> > Subject: Re: [RFC] Proposed location to host the firmware handoff
> > specification.
> >
> > Hi Rob,
> >
> > On Tue, 5 Jul 2022 at 11:27, Rob Herring <robh(a)kernel.org> wrote:
> > >
> > > On Tue, Jul 5, 2022 at 10:37 AM Simon Glass <sjg(a)chromium.org> wrote:
> > > >
> > > > Hi Rob,
> > > >
> > > > On Tue, 5 Jul 2022 at 09:24, Rob Herring <robh(a)kernel.org> wrote:
> > > > >
> > > > > On Thu, Jun 30, 2022 at 3:24 AM Simon Glass <sjg(a)chromium.org>
> > wrote:
> > > > > >
> > > > > > Hi Jose,
> > > > > >
> > > > > > I don't think this is correct. TF-A is a project that aims to
> > > > > > replace U-Boot SPL (and perhaps other components) with more
> > > > > > closed firmware, e.g. the permissive license.
> > > > > >
> > > > > > This spec needs to be in a neutral place, not captive of one project.
> > > > > >
> > > > > > Given its close relationship to device tree, I suggest
> > > > > > github.com/devicetree-org
> > > > >
> > > > > The only relationship to DT I see is DT is a payload as is ACPI.
> > > > > So I don't think dt.org is the right place.
> > > >
> > > > Actually I was about to email you about this. Here's how I see it.
> > > >
> > > > DT is a base structure to allow self-describing data to be stored.
> > > > This is in contrast with ACPI where there is just a header, but it
> > > > is not possible to read the data without specific parsing code for
> > > > the particular table types. Let's ignore ACPI for this discussion.
> > > >
> > > > Unfortunately DT has an overhead and is too expensive for early
> > > > firmware use. It takes 3-4KB of code for libfdt as well as extra
> > > > code and data to read properties, etc.
> > > >
> > > > Transfer List aims to bridge the gap, allowing simple C structures
> > > > to be put into a tagged data structure. The intention is that
> > > > anything more complex than that would use DT.
> > > >
> > > > So there is at least some relationship: simple stuff = Transfer
> > > > list, complex stuff = DT.
> > >
> > > That's a stretch IMO. Perhaps if this was a new output (DTB) format
> > > for easier parsing, I'd agree. It's related to DT only as much as
> > > any other data passed between 2 boot components (remember
> ATAGS?).
> >
> > Yes it is a stretch. I'm just making the case.
> >
> > >
> > > > The Transfer List spec specifies the data format for each entry
> > > > type (the analog to the schema). The DT provides the format and
> > > > schema for more complicated stuff.
> > > >
> > > > We could perhaps put it in an entirely separate repo, but to me
> > > > there is a relationship with DT.
> > >
> > > It seems to me that TF is the main driver and user of this, so I
> > > don't see the issue with them hosting it at least to start as long
> > > as there's not barriers to contributions. It's just a namespace like
> > > devicetree-org. Personally, I'd be more concerned on what the source
> > > format is (I assume the plan is not to commit PDFs) and what the
> > > output generation is. GH has a lot of nice features to support that
> > > which we've used for the DT spec and EBBR.
>
> The default working plan is for the source format to be sphinx.
> Other alternatives/suggestions are welcome.
>
> The output generated should be html (pdf can be supported too for
> 0/negligible effort).
> This generation process can and will most likely evolve over time, depending
> on community direction/desire and the tools we have at our disposal.
> The process should be as automated as possible given any practical
> constraints 😊 .
>
> Regards,
> Jose
>
> >
> > Yes the DT spec works well and I hope the same thing can be used.
> >
> > >
> > > I'm not saying no to devicetree-org either. If the consensus is to
> > > put it there, I really don't care so much as it takes less time to
> > > create a new repo there than to write this email.
> >
> > I do hope that this can become a standard beyond ARM, e.g. with Intel
> > and another i can think of. Intel is essentially trying to create a
> > different thing independently, although has apparently adjusted to use
> > device tree due to its self-describing properties. I suspect that
> > having this spec in an ARM site would be a barrier to that.
> >
> > I am OK with ARM TF being the means to get this into the open, but not
> > with it being the final destination.
> >
> > If we cannot agree on anything better, I am happy with creating a new
> > project on github. We'll need to pick someone to own it and make final
> > calls when there is disagreement.
> >
> > Regards,
> > Simon
> --
> TF-A mailing list -- tf-a(a)lists.trustedfirmware.org To unsubscribe send an
> email to tf-a-leave(a)lists.trustedfirmware.org
Hi all,
Sorry for the late notice, but there will not be an EBBR meeting today. There hasn’t been any really activity recently. Also, I’m handing over EBBR responsibility to Vincent Stehlé, so I’ve cancelled the meeting series if you were receiving that invite. I’ll leave it up to Vincent on when it would be best to resume meetings (probably after the summer).
Let me know if you have any questions
Cheers,
g.
I don't have anything for the agenda, so there is no meeting today
g.
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All,
On today's call I would like to talk about DT in other contexts:
* To describe the contents of a given PCI card (even on a ACPI based system)
* To describe what is attached to a given FDTI device (Multiple I2C
devices etc)
We can open to other topics as well.
Zoom:
2PM UTC, 10AM US east
https://linaro-org.zoom.us/j/96170428801?pwd=elBJNFdVMFJub0UzanFUcVQxTHBqdz…
Thanks,
Bill
--
Bill Mills
Principal Technical Consultant, Linaro
+1-240-643-0836
TZ: US Eastern
Work Schedule: Tues/Wed/Thur
