Hi,
Following the presentation byt Joakim:
https://docs.google.com/presentation/d/1CvKBBZ33ggzyhP2ub8iZ410I_KGrFjHftZL…
The following does **NOT** represent consensus. I'd like to use those
statements to trigger discussion:
- a DTB (say osDTB) is passed from firmware to "downstream" OS;
firmware can't use that DTB (read/write) after that event (Grant -
separate active discussion thread in boot-architecture mailing list)
- that osDTB is distinct from any DTBes that are used by firmware
components. All may still be derived from a single repository (Joakim)
- osDTB can be the result of applying programmatic fixups by diverse
firmware components or by providing separate overlays to be merged
later (last firmware component in the boot chain or by the OS itself),
or by directly merging overlays (FF)
- there are provisions in U-Boot to "sign" pieces of osDTB (Simon)
- we need policies on what can be updated on osDTB, who can do it and
how to verify them (Grant)
- We don't want private keys in device so sign parts of osDTBs
- there are no tools in Linux to deal with overlays (Heinrich), so for
the moment we need firmware to aggregate any overlays into osDTB (FF)
Cordially,
Francois-Frederic
Hi,
please find the meeting notes:
https://docs.google.com/document/d/1bz3BfVlXvvHO-kKC0Y1N2SGqPjlxe5eu3dM8sKU…
As a reminder:
there will be two calls per month:
- 2nd wednesday 2pm UTC
- 4th wednesday 2pm UTC
2pm UTC currently corresponds to 7am PST / 4pm CET.
Call to be added to your agendas if you did not received it by mail:
Device Tree Evolution forum calls.
- 2nd Wednesday of the month prime focus: system device tree and RTOS tools.
- 4th Wednesday of the month prime focus: device tree life cycle,
overlays, authentication and unified repository
Those calls are public. Participants are advised they should not
introduce topics that relate to confidential matters.
https://zoom.us/j/97895025968?pwd=N0JWWFBqY0Npdi9RY2JIOFc1ZzI0UT09
join by phone: https://zoom.us/u/asu8Yfroy
meeting ID: 978 9502 5968
Password: 270935
Cordially,
François-Frédéric
None of the relevent specs (EFI, DT, EBBR) specify the GUID for passing
a DTB. Add it to the EBBR document so it is documented somewhere
relevant.
Fixes: #45
Cc: Andrei Warkentin <awarkentin(a)vmware.com>
Cc: Francois Ozog <francois.ozog(a)linaro.org>
Signed-off-by: Grant Likely <grant.likely(a)arm.com>
---
source/chapter2-uefi.rst | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst
index f6a5802..cf2f652 100644
--- a/source/chapter2-uefi.rst
+++ b/source/chapter2-uefi.rst
@@ -86,6 +86,16 @@ tables.
- An Advanced Configuration and Power Interface [ACPI]_ table, or
- a Devicetree [DTSPEC]_ system description
+A Devicetree system description MUST be provided in Flattened Devicetree (DTB)
+format version 17 or higher.
+The following GUID must be used in the EFT system table to identify the DTB.
+
+.. code-block:: c
+
+ #define EFI_DTB_GUID \
+ EFI_GUID(0xb1b621d5, 0xf19c, 0x41a5, \
+ 0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 0xe0)
+
As stated above, EBBR systems must not provide both ACPI and Devicetree
tables at the same time.
Systems that support both interfaces must provide a configuration
--
2.20.1
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
As per the results of the poll
(https://docs.google.com/spreadsheets/d/1WdsXgUoS3naL_-5eap1e_Sd9t0PM60s0Ljs…),
there will be two calls per month:
- 2nd wednesday 2pm UTC
- 4th wednesday 2pm UTC
2pm UTC currently corresponds to 7am PST / 4pm CET.
Call to be added to your agendas if you did not received it by mail:
Device Tree Evolution forum calls.
- 2nd Wednesday of the month prime focus: system device tree and RTOS tools.
- 4th Wednesday of the month prime focus: device tree life cycle,
overlays, authentication and unified repository
Those calls are public. Participants are advised they should not
introduce topics that relate to confidential matters.
https://zoom.us/j/97895025968?pwd=N0JWWFBqY0Npdi9RY2JIOFc1ZzI0UT09
join by phone: https://zoom.us/u/asu8Yfroy
meeting ID: 978 9502 5968
Password: 270935
Cordially,
François-Frédéric Ozog, Linaro
UEFI 2.8 Errata A changed RuntimeServiceSupported value to be passed via
an EFI_RT_PROPERTIES_TABLE instead of via a runtime variable.
This is a breaking change and we should do a new EBBR release in short
order to keep EBBR up to date with what is in UEFI. However, real world
impact is minimal. U-Boot has already converted to the new method, and
Linux only ever implemented the EFI_RT_PROPERTIES_TABLE method.
Cc: Andrei Warkentin <awarkentin(a)vmware.com>
Cc: Francois Ozog <francois.ozog(a)linaro.org>
Cc: Ard Biesheuvel <ardb(a)kernel.org>
Signed-off-by: Grant Likely <grant.likely(a)arm.com>
---
source/chapter2-uefi.rst | 7 ++++---
source/references.rst | 6 +++---
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst
index 82b1a42..c42691b 100644
--- a/source/chapter2-uefi.rst
+++ b/source/chapter2-uefi.rst
@@ -9,7 +9,7 @@ platforms.
UEFI Version
============
-This document uses version 2.8 of the UEFI specification [UEFI]_.
+This document uses version 2.8 Errata A of the UEFI specification [UEFI]_.
UEFI Compliance
===============
@@ -111,7 +111,7 @@ during both boot services and runtime services.
However, it isn't always practical for all EFI_RUNTIME_SERVICES functions
to be callable during runtime services due to hardware limitations.
If any EFI_RUNTIME_SERVICES functions are only available during boot services
-then firmware shall provide the global `RuntimeServicesSupported` variable to
+then firmware shall provide the `EFI_RT_PROPERTIES_TABLE` to
indicate which functions are available during runtime services.
Functions that are not available during runtime services shall return
EFI_UNSUPPORTED.
@@ -202,7 +202,8 @@ If a platform does not implement modifying non-volatile variables with
SetVariable() after ExitBootServices(),
then firmware shall return EFI_UNSUPPORTED for any call to SetVariable(),
and must advertise that SetVariable() isn't available during runtime services
-via the `RuntimeServicesSupported` variable as defined in [UEFI]_ § 8.1.
+via the `RuntimeServicesSupported` value in the `EFI_RT_PROPERTIES_TABLE`
+as defined in [UEFI]_ § 4.6.
EFI applications can read `RuntimeServicesSupported` to determine if calls
to SetVariable() need to be performed before calling ExitBootServices().
diff --git a/source/references.rst b/source/references.rst
index d901bb1..1eb0509 100644
--- a/source/references.rst
+++ b/source/references.rst
@@ -20,6 +20,6 @@
<https://static.docs.arm.com/den0044/b/DEN0044B_Server_Base_Boot_Requirement…>`_
8 March 2016, `Arm Limited <http://arm.com>`_
-.. [UEFI] `Unified Extensable Firmware Interface Specification v2.8
- <http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_8_final.pdf>`_,
- March 2019, `UEFI Forum <http://www.uefi.org>`_
+.. [UEFI] `Unified Extensable Firmware Interface Specification v2.8 Errata A
+ <https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_A_Feb14.pdf>`_,
+ February 2020, `UEFI Forum <http://www.uefi.org>`_
--
2.20.1
UEFI 2.8 Errata A changed RuntimeServiceSupported value to be passed via
an EFI_RT_PROPERTIES_TABLE instead of via a runtime variable.
This is a breaking change and we should do a new EBBR release in short
order to keep EBBR up to date with what is in UEFI. Unsure what the
overall impact will be. U-Boot implements the variable method which will
need to be changed to a table. It is unclear if any OSes depend heavily
on it being implemented.
Cc: Andrei Warkentin <awarkentin(a)vmware.com>
Cc: Francois Ozog <francois.ozog(a)linaro.org>
Cc: Ard Biesheuvel <ardb(a)kernel.org>
Signed-off-by: Grant Likely <grant.likely(a)arm.com>
---
source/chapter2-uefi.rst | 7 ++++---
source/references.rst | 6 +++---
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst
index fe03ae3..b622abe 100644
--- a/source/chapter2-uefi.rst
+++ b/source/chapter2-uefi.rst
@@ -9,7 +9,7 @@ platforms.
UEFI Version
============
-This document uses version 2.8 of the UEFI specification [UEFI]_.
+This document uses version 2.8 Errata A of the UEFI specification [UEFI]_.
UEFI Compliance
===============
@@ -111,7 +111,7 @@ during both boot services and runtime services.
However, it isn't always practical for all EFI_RUNTIME_SERVICES functions
to be callable during runtime services due to hardware limitations.
If any EFI_RUNTIME_SERVICES functions are only available during boot services
-then firmware shall provide the global `RuntimeServicesSupported` variable to
+then firmware shall provide the `EFI_RT_PROPERTIES_TABLE` to
indicate which functions are available during runtime services.
Functions that are not available during runtime services shall return
EFI_UNSUPPORTED.
@@ -202,7 +202,8 @@ If a platform does not implement modifying non-volatile variables with
SetVariable() after ExitBootServices(),
then firmware shall return EFI_UNSUPPORTED for any call to SetVariable(),
and must advertise that SetVariable() isn't available during runtime services
-via the `RuntimeServicesSupported` variable as defined in [UEFI]_ § 8.1.
+via the `RuntimeServicesSupported` value in the `EFI_RT_PROPERTIES_TABLE`
+as defined in [UEFI]_ § 4.6.
EFI applications can read `RuntimeServicesSupported` to determine if calls
to SetVariable() need to be performed before calling ExitBootServices().
diff --git a/source/references.rst b/source/references.rst
index d901bb1..1eb0509 100644
--- a/source/references.rst
+++ b/source/references.rst
@@ -20,6 +20,6 @@
<https://static.docs.arm.com/den0044/b/DEN0044B_Server_Base_Boot_Requirement…>`_
8 March 2016, `Arm Limited <http://arm.com>`_
-.. [UEFI] `Unified Extensable Firmware Interface Specification v2.8
- <http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_8_final.pdf>`_,
- March 2019, `UEFI Forum <http://www.uefi.org>`_
+.. [UEFI] `Unified Extensable Firmware Interface Specification v2.8 Errata A
+ <https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_A_Feb14.pdf>`_,
+ February 2020, `UEFI Forum <http://www.uefi.org>`_
--
2.20.1
Hi,
Thank you for your participation in yesterday's call.
Here are meeting notes that you can update
<https://docs.google.com/document/d/13TwImAK9bta5_qY2PAFplO6pypd0hpNQNkpkI_W…>as
you
see fit (I think the permissions associated with this new link are correct).
Survey was answered by 12 participants while there were 27 people on the
call. I would be more comfortable to select a time with more responses.
Cordially,
François-Frédéric
--
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi,
Here is the agenda for today's call <http://meet.google.com/oua-wrbf-ppi>:
- DTE activities for the next cycle and overall organization
- Regular meeting setup (survey <https://www.surveymonkey.com/r/F72TLPF>)
- System Device Tree status and roadmap (JIRA?) this topic depends on
presence of SDT stakeholders
- Device Tree specification: its role in the future and short term
- Device Tree lifecycle (what happens to a DT from TFA to OS): a
presentation and a discussion
Cheers
FF
Hi,
I am taking over Steve to drive Device Tree Evolution project except the
System Device Tree which will continue to evolve under the leadership of
Nathalie and Stefano.
To discuss:
- lifecycle (how TFA, OP-TEE, U-Boot and Operating Systems deal with DT and
pass information between them)
- overlays
- unified repo
- summary of System DT activities
I'd like to set up a weekly call starting next week. Please state the best
timeslot in this poll: https://www.doodle.com/poll/k57zhwa4q9caivgy
(the poll proposes the timeslot to be repeated).
By next week, Joakim, Ilias and myself will have prepared some content to
launch/continue debate.
Cordially,
François-Frédéric
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
