*Notes from last week's meeting:Attendees: - Alex Graf (SUSE)- Ryan Harkin
(Linaro)- Rob Herring (Linaro)- Udit Kumar (NXP)- Grant Likely (Arm)- Leif
Lindholm (Linaro)- Bill Mills (TI)- Tom Rini- Peter Robinson (Redhat)-
Michal Simek (Xilinx)- Daniel Thompson (Linaro)- Dong Wei (Arm)Agenda: -
Action item review- [Grant] publish GitHub repo with EBBR text in
reStructuredText markup- [Dong] Get Arm legal approval to relicense and
publish EBBR- Other business- HW IP SharingAction
ItemsDateOwnerAction12-Apr-2018Grant & DongGet Arm legal approval to
relicense and publish EBBR19/04/2018: Approval in process, hope to have
answer by next week12-Apr-2018GrantPublish GitHub repo with EBBR text in
reStructuredText markup19/04/2018: Repo is created, but cannot publish
yet19-Apr-2018*new*BillWrite recommended policy for sharing HW between
firmware and OS19-Apr-2018*new*LeifDocument specification text for
platforms which do not support persistent variables, or do not support
runtime {Get,Set}Variable() NotesAction item review - Relicensing of EBBR
by ARM- Internal support is there, Grant is writing draft of legal texts-
“Should be done by next week” - ;-)- Github repo with current EBBR text in
reStructuredText- 50% complete- Repo is created and ready to roll but won’t
hit github until it is approved by Arm legal- Expect to use github wiki,
issue tracker, etc. At least for the short term.AOB - HW IP Sharing of
peripherals between OS and firmware- eMMC is a good example, I2C can be
another in some cases- Can EBBR help solve this issue?- Grant: One answer
could be: For any of these platforms a piece of hardware should have only
one master. If it is described in DT then OS has implicit permission to use
and abuse it.- Grant: EBBR should not dictate having anything resident in
the same exception level as the OS.- Udit: Seeking agreement that there are
some devices that need to be shared. EFI runtime variables is an especially
important case for EBBR- Bill: Base case is to agree with Grant… but…
firmware can expose services to allow a virtual device in Linux to access
features- Peter: Raspberry Pi has GPIO and ??? that is managed by the video
controller, accessed from kernel by a mailbox mechanism- Peter: Arm has
just released a new h/ware standard/recommendation to try and solve some of
these problems- Grant: What is scope of EBBR? Allows distros to support
embedded boards without cute embedded nonsense hacks. General device
sharing is not in scope.- Daniel: Agree with above… except for EFI runtime
variables which we would (or may) like EBBR to be able to rely on.- Grant:
Try to solve this in a wider space (UEFI forum) and then EBBR can inherit
the solution. - Bill: EFI runtime variables are easy if you have specific
hardware that is uniquely owned by firmware (NOR flash, etc).- What are
actions arising from this?- Ok not to have general solution- Action Bill
Mills: Document “something” about EFI variables for EBBR spec- Leif
(reluctantly) will look after take this to EFI forum (but not ready to go
to forum yet)- Device tree overlays- No common method of handling device
tree overlays- Peter: Alex G. and I discussed heavily at connect. Some
interest in solving this within grub since no need to push things down into
TianoCore/EDK2 and u-boot.- Alex: Have logic in firmware that can enumerate
“Hat”s and create EFI object for them. These objects could then be backed
by DTBOs - either by grabbing them from the device (EEPROM) or by a stored
blob in firmware. Grub for example could then also be taught about these
objects and DTBO support, so an OS could store its own overlays. EDK2 has
the hat logic support today and already does create objects.- Bill: FIT
handles this problem today… but also bundles in lots of other features. Not
clear how distros feel about this.- Tom: Let’s focus on what EBBR dictates
first!- Grant: Would like DT update to be part of EBBR but its not clear
whether overlay should be in scope at all.- Q: Where do we look to find out
what UEFI features u-boot supports today (Bill)- Alex: No exhaustive list
of present or absent features is available. To find what is missing “all”
we need to is run the SCT (self certification test) but u-boot isn’t quite
capable of running that quite yet (uefi shell, a prereq, is nearly there)-
Grant: What is list of platforms that are “good” for playing with EFI
features. RPi?- Alex: qemu is in good condition but many other choices-
Runtime variables- Daniel: If EBBR recommends no runtime variable then EBBR
must recommend a protocol for distros to adopt- Grant: EBBR will never
recommend no runtime variables… but it might allow it- Daniel: Agree… but
even allowing forces EBBR to recommend alternative- Action (Leif, also
reluctantly): Make this a bug and provide a recommendation*On Thu, Apr 19, 2018 at 3:59 PM, Grant Likely <grant.lik...@arm.com> wrote: > Hi folks, > > Weekly EBBR meeting starts in about 1/2 hour. Dial in details below. > Once again the agenda is very short, but I'll open it up to other topics > after action item review. I think there was some interest in talking > about DT overlay handling. > > Notes are being captured in the following Google doc. I would greatly > appreciate help with taking meeting minutes. > > https://docs.google.com/document/d/1RdlFp5SIrvjcVOGoGEFVYDsq > TqFBJHugbBMV5MuXUhw/edit?usp=sharing > > Agenda: > 1) Action item review > 2) Any other business > > Cheers, > g. > _______________________________________________ boot-architecture mailing list boot-architecture@lists.linaro.org https://lists.linaro.org/mailman/listinfo/boot-architecture
