Looks t...@lists.trustedfirmware.org got dropped. Adding that back in.
Joanna
On 19/05/2021, 15:33, "Joanna Farley" <joanna.far...@arm.com> wrote:
It’s a bit short notice to host another TF-A Tech-forum call on this
tomorrow for a live debate as well as Manish who led the call last time is not
available this week. So I propose our next TF-A Techforum session on Thursday
3rd June at 4pm BST and between now and then email discussions can possibly be
pursued.
From a TF-A perspective we want to help facilitate a number of
segments/use-cases we heard about as Madhu mentions below. As such any
enablement we can provide in TF-A common code would be good to identify that
contributors to other segments/use-cases can build upon in shared platform code
in TF-A or elsewhere outside the TF-A repository of that works better for those
segments/use-cases.
Thanks
Joanna
On 19/05/2021, 03:50, "Madhukar Pappireddy" <madhukar.pappire...@arm.com>
wrote:
Attached slides presented by Manish in the TF-A tech forum.
-----Original Message-----
From: TF-A <tf-a-boun...@lists.trustedfirmware.org> On Behalf Of
Madhukar Pappireddy via TF-A
Sent: Tuesday, May 18, 2021 8:59 PM
To: Joanna Farley <joanna.far...@arm.com>; Okash Khawaja
<okash.khaw...@gmail.com>; Simon Glass <s...@chromium.org>
Cc: Harb Abdulhamid OS <abdulha...@os.amperecomputing.com>; Boot
Architecture Mailman List <boot-architect...@lists.linaro.org>; Ed Stuber
<edstu...@amperecomputing.com>; Arjun Khare <akh...@amperecomputing.com>;
U-Boot Mailing List <u-boot@lists.denx.de>; t...@lists.trustedfirmware.org;
Paul Isaac's <paul.isa...@linaro.org>; Ron Minnich <rminn...@google.com>; Moe
Ammar <m...@amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
information passing between boot stages
Hi,
I tried to summarize the discussions in the previous TF-A tech forum
regarding the proposal to adopt Hand-off Blocks (HOBs) for passing information
along the boot chain. I am certain I could not capture all suggestions/concerns
brought up during the call. I apologize if I missed and/or misinterpreted any
comments and would appreciate it if everyone could share their thoughts in
response to this email thread.
The idea is to share information to other boot phases:
> Dynamic information: Created during runtime. Shared in the form of a
chain of blobs(built as a linked list of C structure objects i.e., HOB list).
> Static information: Known at compile time. Historically, shared
through the use of Device Tree/ACPI tables
Both the above requirements are common in many ecosystems and need to
co-exist.
There are broadly 3 problems to solve:
1. Format of HOB structures: It looks like the consensus is that we
could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in
u-boot).
2. Identification of HOB list entries: There is a debate about whether
tags would suffice or if the HOB list producer and consumer would depend on
UUID/GUIDs for identifying a specific HOB structure. Another suggestion was to
use a hybrid approach. Reserve a single tag ID for identifying/constructing a
HOB structure that further leverages UUID based identifier. This way, the
generic HOB list doesn't need to support UUIDs and can work with tags.
3. The design contract for the static interface between two boot
phases: The problem at hand is whether to pass a pointer to a HOB list or a
device tree blob through the general-purpose registers for configuration
hand-off between two boot phases. Some proposals that came up:
> Proposal 1: Always pass a pointer to the device tree blob
through the GP register and capture the pointer to the HOB list as a property
of a node that is uniquely identifiable by the downstream boot phase. This
needs to define a device tree binding such that producer and consumer agree on
the information passed.
> Proposal 2: Pass a pointer to a generic container through the
GP register that can be interpreted appropriately by both boot loaders(i.e.,
producer and consumer of the boot info). This container can either be a dtb or
a HOB list which can be simply inferred by checking for a magic header that
indicates if the buffer appears to be a flattened device tree.
> One another concern that was brought up offline is to make
sure we don't break current design contracts between various boot loader phases
in TF-A. Many of the general-purpose registers have a designated purpose such
as to share configurations between BL images( such as firmware config dtb, SoC
config dtb, Non trusted firmware config dtb, memory layout, entry point info,
etc.).
If I am not mistaken, a single design may not fit the needs of every
segment(client, Infra, embedded) and the forum is open to solutions tailored
for individual segments. Joanna will be sending a follow up email with more
information about future TF-A tech forums that serves as a platform for further
discussions.
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-boun...@lists.trustedfirmware.org> On Behalf Of Joanna
Farley via TF-A
Sent: Sunday, May 16, 2021 5:19 AM
To: Okash Khawaja <okash.khaw...@gmail.com>; Simon Glass
<s...@chromium.org>
Cc: Harb Abdulhamid OS <abdulha...@os.amperecomputing.com>; Boot
Architecture Mailman List <boot-architect...@lists.linaro.org>;
t...@lists.trustedfirmware.org; Ed Stuber <edstu...@amperecomputing.com>; Arjun
Khare <akh...@amperecomputing.com>; U-Boot Mailing List <u-boot@lists.denx.de>;
Paul Isaac's <paul.isa...@linaro.org>; Ron Minnich <rminn...@google.com>; Moe
Ammar <m...@amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
information passing between boot stages
Apologies I failed with the recording. Manish/Madhu will reply early
next week with the slides and some notes to help with a follow up session which
we hope to hold this Thursday. Invite and agenda will also be sent out early
next week.
Thanks
Joanna
On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A"
<tf-a-boun...@lists.trustedfirmware.org on behalf of
t...@lists.trustedfirmware.org> wrote:
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<t...@lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit
UUID provides to an open project. I'd like to propose something different, more
in the spirit of open collaboration. I also worry that the word 'standard'
seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring
closed-source firmware and the continued decline of open-source projects. It
really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for
'private' use. If you want to collaborate across projects outside your
company, you either need to allocate a 'public' ID or agree privately between
the parties which private ID to use.
>
> This means that the default and easiest option is for
collaboration and a public ID, with private ones (whose purpose may be secret)
reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS
<abdulha...@os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the
discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves
reserving a single tag ID for the purpose of construction UEFI PI HOB List
structure, and that tag would be used to identify a HOB-specific structure that
does leverage UUID based identifier. This will eliminate the burden of having
to support UUID as the tag, and this enables projects that require UUID based
identifiers for the broad range of HOB structures that need to be produced
during the booting of the platform. Once we have a tag for a HOB list, this
will enable various HOB producers that can add/extend the HOB list in TF-A code
(or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other
side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB
structures in a standard way using TF-A, they would wrap it up in a
BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we
identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward
to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <manish.pand...@arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.o...@linaro.org>
>> Cc: Simon Glass <s...@chromium.org>; Julius Werner
<jwer...@chromium.org>; Harb Abdulhamid OS <abdulha...@os.amperecomputing.com>;
Boot Architecture Mailman List <boot-architect...@lists.linaro.org>;
t...@lists.trustedfirmware.org; U-Boot Mailing List <u-boot@lists.denx.de>;
Paul Isaac's <paul.isa...@linaro.org>; Ron Minnich <rminn...@google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
(HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue
our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00
– 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in
TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related
with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion
on dynamic information passing and if time permits, we can cover static
information passing. The purpose of the call is to have an open discussion and
continue the discussion from the trusted-substrate call[2] done earlier. We
would like to understand the various requirements and possible ways to
implement it in TF-A in a generalized way so that it can work with other
Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist
implementation, which uses tag values. Question, can this be enhanced to use
hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of
HoB data structure.
>>
>> References:
>>
>> [1]
https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2]
https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQnHTqzgA5Wav0qOO8n7SAM0yj-Hg.mLyFkVJNB1vDKqw_
Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> t...@lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> t...@lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate
and it is not restricted to Trusted Firmware project members. It will operate
under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via
the TF-A mailing list and also published on the Trusted Firmware website.
Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
>> +16465588656,,9159704974# US (New York)
>>
>> +16699009128,,9159704974# US (San Jose)
>>
>>
>>
>> Dial by your location
>>
>> +1 646 558 8656 US (New York)
>>
>> +1 669 900 9128 US (San Jose)
>>
>> 877 853 5247 US Toll-free
>>
>> 888 788 0099 US Toll-free
>>
>> Meeting ID: 915 970 4974
>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.o...@linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <manish.pand...@arm.com>
>> Cc: Simon Glass <s...@chromium.org>; Julius Werner
<jwer...@chromium.org>; Harb Abdulhamid OS <abdulha...@os.amperecomputing.com>;
Boot Architecture Mailman List <boot-architect...@lists.linaro.org>;
t...@lists.trustedfirmware.org <t...@lists.trustedfirmware.org>; U-Boot Mailing
List <u-boot@lists.denx.de>; Paul Isaac's <paul.isa...@linaro.org>; Ron Minnich
<rminn...@google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
(HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>>
https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQnHTqzgA5Wav0qOO8n7SAM0yj-Hg.mLyFkVJNB1vDKqw_
Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting
time. I have now understood: the Collaborate portal uses a specific calendar
which is tied to US/Chicago timezone while the actual Google Calendar is tied
to Central Europe timezone. I am going to drop the Collaborate portal and use a
shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on
what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A
<t...@lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing
mechanism to pass parameters across boot stages using linked list of tagged
elements (as suggested by Julius). It has support for both generic and
SiP-specific tags. Having said that, it does not stop partners to introduce new
mechanisms suitable for their usecase in platform port initially and later move
to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific
implementation of memory tag(speed/NUMA topology etc) which can be evaluated
and discussed for generalization in future. The tag will be populated in BL2
stage and can be forwarded to further stages(and to BL33) by passing the head
of list pointer in one of the registers. Initially any register can be used but
going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar
to what TF-A is using, if there is consensus of using bloblist/taglist then
TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in
different projects is maintainability, this can be avoided by having a single
copy of these structures in TF-A (kept inside "include/export" which intended
to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of
Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-boun...@lists.trustedfirmware.org> on behalf of
Julius Werner via TF-A <t...@lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <s...@chromium.org>
>> Cc: Harb Abdulhamid OS <abdulha...@os.amperecomputing.com>; Boot
Architecture Mailman List <boot-architect...@lists.linaro.org>;
t...@lists.trustedfirmware.org <t...@lists.trustedfirmware.org>; U-Boot Mailing
List <u-boot@lists.denx.de>; Paul Isaac's <paul.isa...@linaro.org>; Ron Minnich
<rminn...@google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
(HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a
(very simple) mechanism like this:
>>
>>
>>
>>
https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/refs/heads/master/include/export/lib/bl_aux_params/bl_aux_params_exp.h
>>
>>
https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/refs/heads/master/lib/bl_aux_params/bl_aux_params.c
>>
>>
https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/+/refs/heads/master/plat/rockchip/common/params_setup.c
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is
split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to
spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is
currently being used by some platforms that run coreboot in place of BL1/BL2,
to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as
possible and avoiding complicated and bloated data structures with UUIDs. You
usually want to parse something like this as early as possible in the passed-to
firmware stage, particularly if the structure encodes information about the
debug console (like it does for the platforms I mentioned above). For example,
in BL31 this basically means doing it right after moving from assembly to C in
bl31_early_platform_setup2() to get the console up before running anything
else. At that point in the BL31 initialization, the MMU and caches are
disabled, so data accesses are pretty expensive and you don't want to spend a
lot of parsing effort or calculate complicated checksums or the like. You just
want something extremely simple where you ideally have to touch every data word
only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A
<t...@lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS
<abdulha...@os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that
there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon
below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will
make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as
there are typically vendor specific structures beyond the resource descriptor
HOB, which provides only a small subset of the information that needs to be
passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware
that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2,
AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some
point). In other-words, we are trying to come up with a TF-A that would be
completely agnostic to the implementation of BL33 (i.e. BL33 is built
completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not
building vertically integrated systems with a single entity compiling
firmware/software stacks like most folks in TF-A have become use to. There are
two categories of higher level firmware code blobs in the server/datacenter
model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2,
BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33
and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by
having multiple entities involved in delivering the entire firmware stack:
IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range
of memory devices, we need a crisp and clear contract between the SoC firmware
that initializes memory (e.g. BL2) and how that platform boot firmware (e.g.
BL33) gathers information about what memory that was initialized, at what
speeds, NUMA topology, and many other relevant information that needs to be
known and comprehended by the platform firmware and eventually by the platform
software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems
with DT:
>>
>> DT requires more complicated parsing to get properties, and even
more complex to dynamically set properties – this HOB structures may need to be
generated in boot phases where DDR is not available, and therefore we will be
extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a
list of pointers to simple C structures that code cast (e.g. JEDEC SPD data
blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs
with what we are doing here, because those specs and concepts were developed
for a completely different purpose (i.e. abstractions needed for OS / RTOS
software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining
SMC’s for something that should be one way information passing. Every SMC we
add is another attack vector to the secure world and an increased burden on the
folks that have to do security auditing and threat analysis. I see no benefit
in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to
discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly
reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in
having some kind of unique identifiers (e.g. UUID or some unique signature) so
that we can tie standardized data structures (based on some future TBD specs)
to a particular ID. For example, if the TPM driver in BL33 is looking for the
TPM structure in the HOB/BOB list, and may not care about the other data blobs.
The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it
should switch from an auto-allocating enum to one with explicit values for each
entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with
tag when you have eco-system with a lot of parties doing parallel development,
you can end up with tag collisions and folks fighting about who has rights to
what tag values. We would need some official process for folks to register
tags for whatever new structures we define, or maybe some tag range for vendor
specific structures. This comes with a lot of pain and bureaucracy. On the
other hand, UUID has been a proven way to make it easy to just define your own
blobs with *either* standard or vendor specific structures without worry of ID
collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I
think we actually want something that can be shared between projects and orgs,
so some amount of coordination could be considered a benefit. It could just be
a github pull request. I find the UUID unfriendly and not just to code size and
eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g.
see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM"
},
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database
ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database
9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory"
},
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that
small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID
or not during the call… but again, boblist seems like a reasonable starting
point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.o...@linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.o...@linaro.org>; Ron Minnich
<rminn...@google.com>; Paul Isaac's <paul.isa...@linaro.org>
>> Cc: Simon Glass <s...@chromium.org>; Harb Abdulhamid OS
<abdulha...@os.amperecomputing.com>; Boot Architecture Mailman List
<boot-architect...@lists.linaro.org>; t...@lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
(HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be
also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A
<t...@lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate
zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3,
S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology
detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform
Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is
EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be
related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm)
lists memory from the booting NUMA node, other platforms (x86) lists all memory
from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up
to the handover function (as defined in the Device Tree technical report) which
can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to
actually query information or request actions to be done (this is a model
actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot,
TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent"
usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <s...@chromium.org>
wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within
U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here:
https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog
<francois.o...@linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List
<boot-architect...@lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to
accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to
BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific
object
>> > 2) BLx called by BLy by a platform specific SMC to get
information
>> > 3) BLx called by BLy by a platform specific SMC to perform
Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that
any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on
architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult
to implement
>> > schemes such as pruning a DT because device assignment in the
secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE
complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list
of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity |
information
>> > exchanged:
>> > dram | TFA | TFA
|
>> > <format to be detailed, NUMA topology to build the SRAT table
or DT
>> > equivalent?>
>> > PSCI | SCP | TFA?
|
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA.
|
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > t...@lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption
of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the
TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a
pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM
Server SoC’s
>> > > designed to enable a broad range of highly configurable
datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB
may be used for
>> > > transitioning between the PEI and DXE boot phases, which is
a good
>> > > reference point for this discussion, but not necessarily the
exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure
passed in between
>> > > two boot phases. This is information that was obtained
through discovery
>> > > and needs to be passed forward to the next boot phase
*once*, with no API
>> > > needed to call back (e.g. no call back into previous
firmware phase is
>> > > needed to fetch this information at run-time - it is simply
passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases.
If there are
>> > > more than one HOB that needs to be passed, this can be in a
form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of
pointers to
>> > > HOB structures, used to locate a HOB of interest (based on
UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may
rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly
configurable
>> > > systems that must rely on flexible discovery mechanisms to
initialize and
>> > > boot the system. This is especially helpful when you have
multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM
Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This
means that a
>> > > single ARM SoC that a SiP may deliver to customers may
provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to
support a broad
>> > > range of platform designs and configurations in order to
boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code).
In order to
>> > > achieve this, the platform configuration must be
*discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree
based
>> > > enumeration. The mechanisms of discovery may differ broadly
depending on
>> > > the relevant industry standard, or in some cases may have
rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range
DIMM memory
>> > > population/topologies, all the necessary information
required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect
(SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants
could be supported
>> > > with a single TF-A binary. Not only is this information
required to
>> > > initialize memory in early boot phases (e.g. BL2), the
subsequent boot
>> > > phases will also need this SPD info to construct a system
physical address
>> > > map and properly initialize the MMU based on the memory
present, and where
>> > > the memory may be present. Subsequent boot phases (e.g.
BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating
systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI
tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor
specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the
passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in
the future
>> > > there may be benefit of defining standard HOBs. This may be
useful for
>> > > memory discovery, passing the system physical address map,
enabling TPM
>> > > measured boot, and potentially many other common HOB
use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market
segment if the
>> > > TF-A community would adopt this concept of information
passing between all
>> > > boot phases as opposed to rely solely on device tree
enumeration. This is
>> > > not intended to replace device tree, rather intended as an
alternative way
>> > > to describe the info that must be discovered and dynamically
generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the
adoption of
>> > > HOBs as a mechanism used for information exchange between
each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)?
Longer term we
>> > > want to explore standardizing some HOB structures for the
BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on
this being a
>> > > useful mechanism used to pass information between each boot
stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > t...@lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing
Group*
>> > T: +33.67221.6485
>> > francois.o...@linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architect...@lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
Group
>>
>> T: +33.67221.6485
>> francois.o...@linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> t...@lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
Group
>>
>> T: +33.67221.6485
>> francois.o...@linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> t...@lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> t...@lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
Group
>>
>> T: +33.67221.6485
>> francois.o...@linaro.org | Skype: ffozog
>>
>>
>
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