- TF-A - lists.trustedfirmware.org

by guillaume pivetta

Hi, I’m trying to implement a secure boot on a STM32MP1 without using the FIP file. For now , I am not able to use FIP format during the boot process so I use a depreciated boot process with TF-Av2.2 as FSBL and U-Boot as SSBL to boot my Board. My boot process do Romcode -> TF-A (BL2) -> SP_min (BL32) -> U-Boot (BL33) -> Linux kernel I succefully implemented signature authentification between U-Boot and Linux image, but between TF-A and U-Boot it’s a little bit harder. I learned on ST wiki how to sign my u-boot binary with the STM32MP_SigningTool_CLI, but when I sign my binary with a custom private key, TF-A don’t authentified it on boot, even if i tryed to pass my key to TF-A at compilation time with the BL33_KEY argument, which i think is dedicated to the FIP usage. I found, in the sources of TF-A, what I think being a developpement key, named « arm_rotpk_ecdsa.pem ». And when I sign my binary with this key, I am able to perform the signature check and continu my boot process. So I tryed to change this key with a custom one and recompile TF-A to update the key in the final binary, but it seem that it is not so simple. I found yesterday that the auth_mod_init() function wasn’t call because I had forgotten the TUSTED_BOARD_BOOT=1 compilation argument. But when I activate it, the compilation doesn’t work and i see « build/arm-trusted-firmware-v2.2/bl2/bl2_main.c:91: undefined reference to `auth_mod_init' » Whitch traditionnaly append when linker don’t find the .o where the functions are implemented. I would like to know if it is possible to implement some kind of authentification with custom keys without FIP and if yes where can i find some hints/ressources/tutorial ? I don’t find a lot of ressources about secure boot without FIP so I hope you will be able to help me.

3 years, 2 months

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Re: [TF-A] Please provide option to build with GICv3 for qemu

by Jens Wiklander

Hi Alexey, On Thu, Jul 22, 2021 at 10:14 AM Alexey Kazantsev via TF-A <tf-a(a)lists.trustedfirmware.org> wrote: > > Hello! > > Please add a build option for selecting GICv3 instead of GICv2 for QEMU > platform. > > There is the following line in plat/qemu/qemu/platform.mk : > QEMU_USE_GIC_DRIVER := QEMU_GICV2 > > It doesn't imply setting GICv3 externally by build system of other > projects, like OP-TEE. When building with OP-TEE we're overriding this assignment by passing "QEMU_USE_GIC_DRIVER=$(TFA_GIC_DRIVER)" (where TFA_GIC_DRIVER is either QEMU_GICV3 or QEMU_GICV2) on the command line. This is now tested on a regular basis since we've recently added Xen support to the OP-TEE build setup on QEMU V8 and this depends on using GICv3 instead of GICv2. Does this help in your case? Cheers, Jens

3 years, 2 months

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Please provide option to build with GICv3 for qemu

by Alexey Kazantsev

Hello! Please add a build option for selecting GICv3 instead of GICv2 for QEMU platform. There is the following line in plat/qemu/qemu/platform.mk : QEMU_USE_GIC_DRIVER := QEMU_GICV2 It doesn't imply setting GICv3 externally by build system of other projects, like OP-TEE. Best regards, Aleksey.

3 years, 2 months

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Re: [TF-A] [RFC] QTI platform ports violate Binary Components policy?

by Julius Werner

Hi Tom, Thanks for your interest in the SC7180 TF-A port! You're asking fair questions about a difficult situation, so let me try to add some background: The binary component policy was actually written specifically as part of the discussions about adding the SC7180 port, to lay some guidelines and ground rules about how to deal with binary components (which already existed in some other platform ports beforehand). This case was discussed in-depth with the project leaders and the trustedfirmware.org Board beforehand, and it was always understood that this would have to be a tricky compromise. As you may know, devices (e.g. Android phones) with Qualcomm chipsets generally do not run TF-A, but instead run Qualcomm's proprietary trusted OS and secure monitor (QTEE). The TF-A port was more of an experimental side project (which has by now resulted in a few SC7180-based Chromebooks being sold with TF-A, but the much larger phone market continues to use QTEE), so unfortunately the TF project's position to make demands is not yet as solid as you may think. Basically, we could have either made these compromises or continue to not support Qualcomm chipsets at all, so due to their prevalence in the ecosystem we decided it would be worth it to start like this, try to make the situation as good as it can get, and then hopefully improve on that in future chipset generations. The binary policy is meant as more of a decision guideline and individual cases are ultimately up to the Board. FWIW maybe I slightly mis-summarized the policy in the text added to the contributing.rst document -- I think saying that the *majority* of the platform port (in terms of bytes of code) should be open source, while a good ambition in general, was never realistic for SC7180. The full document in https://git.trustedfirmware.org/tf-binaries.git/tree/readme.rst instead says "Binary components that contain all meaningful functionality of a platform port" are not accepted -- the intention is that there are pieces large enough to be worth modifying in the open source part, while allowing vendors to keep functionality proprietary that they absolutely do not want (or are not allowed) to disclose. For SC7180, things like UART, SPMI, PMIC and RNG drivers as well as SMC validation are implemented in open source (and as you noticed some of those were ported piecemeal at later points of the development process). I'll be the first to admit that this isn't a lot and we absolutely want to do more, but it is a tricky and very time-consuming process both in identifying the exact parts that can be open-sourced without IP concerns and then actually doing the work (since the qtiseclib code is still proprietary even if there is a Linux driver for the same subsystem, we can't just copy things over, it has to be carefully rewritten and revalidated). The state you see the SC7180 port in right now is basically just as far as we got over the course of this project (and believe me it took a lot of effort already, even if it may not look like much). Hopefully we can make further progress with the next chipset. Also, just as a note, we didn't actually end up hosting qtiseclib in the TF binary repository in the end, due to concerns about details in the license text that couldn't be resolved. It is instead hosted by the coreboot.org project at the moment. I'm not sure if this technically means that the TF binary component policy applies to this blob or not (from a strict reading of the text I would say it doesn't), but that's not really that relevant... like I said, in the end the Board makes final decisions about whether a platform port is accepted into the repository or not on a case by case basis, and the policy is just a general guideline. The general goal is to make sure the TF-A ports are actually useful to open source developers while allowing for pragmatic compromises in tricky situations like this, and in this case we decided that allowing this port would be more useful than not (although it's certainly on the edge). On Tue, Jul 20, 2021 at 2:05 AM Tom Johnsen <tomjohnsen(a)protonmail.com> wrote: > > Hello! > > I recently discovered the TF-A port for QTI SC7180 and was very happy > to see this. I always thought it would have been great if Qualcomm made > (open-source) TF-A ports for their platforms. For example, I would be > interested in TF-A for the DragonBoard 820c (APQ8096E). > Unfortunately, after talking to some other people I have been told > it is unlikely that Qualcomm will ever have this. :-/ > > I am not much of a firmware developer but I was curious so I wanted to > check how much SoC-specific code is actually needed for a TF-A port. At > first I was surprised - the QTI platform ports seem fairly simple, there > is not much SoC-specific code at all. However, it looks like the reason for > that is that almost all of the SoC-specific code is actually contained in a > proprietary "qtiseclib" blob that is statically linked into the bl31.bin. > > I did not really expect to see something like that in a public > open-source project, especially not one as security-critical as TF-A. > It looks like some binary components are indeed allowed as per the > Contribution Guidelines (1). Yet, after reading them and looking at the > code again I wonder how the amount of functionality implemented > in the "qtiseclib" could really conform to these guidelines? > > I quote them here (from (1)) for convenience: > > > Binary components must be restricted to only the specific > > functionality that cannot be open-sourced and must be linked into a > > larger open-source platform port. The majority of the platform port > > must still be implemented in open source. Platform ports that are > > merely a thin wrapper around a binary component that contains all the > > actual code will not be accepted. > > There are two main reasons why I do not think that the "qtiseclib" > conforms to these guidelines. > > --- 1. "Majority of the platform port must be open-source" --- > > I have built TF-A for QTI SC7180 according to the documentation (2). > The resulting bl31.bin has a size of 182088 bytes. The linker conveniently > produces a "bl31.map" file that shows exactly which part of the binary > comes from which component of the TF-A port. It can be analyzed easily, > for example with fpv-gcc (3). > > The following table shows the distribution of the bl31.bin: > > +-------------+----------+-----+ > | Component | Size (B) | % | > +-------------+----------+-----+ > | libqtisec.a | 147344 | 81% | > | Other BL31 | 23838 | 13% | > | plat/qti | 5222 | 3% | > | Padding | 3863 | 2% | > | libc.a | 1821 | 1% | > +-------------+----------+-----+ > > Clearly, the libqtisec.a dominates with 81%. The open-source part of the > QTI TF-A platform port (plat/qti) is merely 3% of the final binary. > > Perhaps it is just large static data tables? The following table shows > only the distribution of .text symbols (excluding libc and "Other BL31"): > > +-------------+----------+-----+ > | Component | Size (B) | % | > +-------------+----------+-----+ > | libqtisec.a | 75792 | 95% | > | plat/qti | 3920 | 5% | > +-------------+----------+-----+ > > I do not see any way to interpret this as "the majority of the platform > port is open-source". It is hard to find any substantial functionality > that does not end up calling into the proprietary qtiseclib. In my > opinion, the port is hardly more than "a thin wrapper around a binary > component" which is explicitly forbidden in the guidelines. > > --- 2. "Binary components should be as minimal as possible" --- > > It is hard to judge this given that the license for "qtiseclib" (obviously) > does not allow reverse-engineering. However, just judging from some of the > symbol names that I see visibly in the "bl31.map" Qualcomm seems to have > spent little effort to keep the binary component actually minimal. > > "qtiseclib" also contains code for IP blocks that have public > open-source drivers in Linux, including for: > > - TLMM (GPIO) > - GCC (Clocks) > - rpmh > > Perhaps some "secret" registers are programmed there but it is hard to > believe that there is no overlap that could have been made open-source. > > This is also quite visible based on changes that were made later. > The PRNG and SPMI driver were moved out of "qtiseclib" later (4, 5) > and both can be found similarly in Linux. > > --- Conclusion --- > > How does this conform to the Binary Components policy that is part of > the contribution guidelines? Was this not checked during review? > > All in all I cannot help but get the feeling that Qualcomm has fairly > little interest to have open-source firmware. Not even simple hardware > initialization that probably exists similarly in open-source drivers > has been implemented in open-source code. The resulting bl31.bin can > be hardly called "open-source" when 81% of it is actually proprietary. > > If this is intended and considered acceptable I suggest rewriting the > "Binary Components" policy to explicitly allow vendors to require > any amount of proprietary code for their TF-A ports. Personally, I think > this is a very bad idea though and just encourages all other vendors to > do the same in the future. TF-A (as a trusted reference implementation) > is in a good position to make certain demands that must be met for > inclusion in the upstream tree. > > I am mainly sad about this because this certainly means that only > Qualcomm can make such ports by providing the "qtiseclib" that contains > most of the functionality. Perhaps open-source code could have been > adjusted by the community to other platforms with some effort. > > Thanks for reading. > ~ Tom > > (1) https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.htm… > (2) https://trustedfirmware-a.readthedocs.io/en/latest/plat/qti.html > (3) https://github.com/ebs-universe/fpv-gcc > (4) https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4885 > (5) https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4409

3 years, 2 months

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Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages

by Julius Werner

> > Thank you all for your feedback. > > It appears that in theory we are all happy with using bloblist with few > implementation details which needs to be taken care of during > implementation. > Just to clarify: are you using "bloblist" as a general term for the concept of a simple linked list of tagged data blobs, or to refer specifically to the U-Boot implementation with that name? The existing TF-A implementation (bl_aux_params) is basically identical in concept to the U-Boot bloblist, but not binary compatible. Are we talking about just keeping that, or throwing it away in order to reimplement the exact structure U-Boot is using? (I would prefer to keep the bl_aux_params as they are to avoid disrupting existing uses, of course. Making backwards-incompatible changes to an interface that passes across multiple repos and firmware components is always a big pain.)

3 years, 2 months

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FIP and FCONF for STM32MP1

by Yann Gautier

Hi everyone, I've just pushed a series to support FIP and FCONF on STM32MP1 platform. I haven't put any TF-A maintainers yet, but feel free to comment. Just be aware that I'll be out of office for the 3 and a half coming weeks, so I won't be able to push new patch sets. But I'll try to connect from time to time to answer questions, if any. Best regards, Yann

3 years, 2 months

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Canceled event with note: TF-A Tech Forum @ Thu Jul 15, 2021 4pm - 5pm (BST) (tf-a@lists.trustedfirmware.org)

by joanna.farley＠arm.com

This event has been canceled with this note: "Cancelling the TF-A Tech forum this week as the majority of attendees have clashing events and cannot join." Title: TF-A Tech Forum 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/Tr… Firmware is inviting you to a scheduled Zoom meeting.Join Zoom Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One 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-freeMeeting ID: 915 970 4974Find your local number: https://zoom.us/u/ad27hc6t7h   When: Thu Jul 15, 2021 4pm – 5pm United Kingdom Time Calendar: tf-a(a)lists.trustedfirmware.org Who: * Bill Fletcher - creator * marek.bykowski(a)gmail.com * okash.khawaja(a)gmail.com * tf-a(a)lists.trustedfirmware.org Invitation from Google Calendar: https://calendar.google.com/calendar/ You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively you can sign up for a Google account at https://calendar.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organizer and be added to the guest list, or invite others regardless of their own invitation status, or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

3 years, 2 months

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New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware

by scan-admin＠coverity.com

Hi, Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. 2 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. New defect(s) Reported-by: Coverity Scan Showing 2 of 2 defect(s) ** CID 371992: Control flow issues (DEADCODE) /plat/qemu/common/qemu_pm.c: 116 in qemu_validate_ns_entrypoint() ________________________________________________________________________________________________________ *** CID 371992: Control flow issues (DEADCODE) /plat/qemu/common/qemu_pm.c: 116 in qemu_validate_ns_entrypoint() 110 /* 111 * Check if the non secure entrypoint lies within the non 112 * secure DRAM. 113 */ 114 if ((entrypoint >= NS_DRAM0_BASE) && 115 (entrypoint < (NS_DRAM0_BASE + NS_DRAM0_SIZE))) >>> CID 371992: Control flow issues (DEADCODE) >>> Execution cannot reach this statement: "return 0;". 116 return PSCI_E_SUCCESS; 117 return PSCI_E_INVALID_ADDRESS; 118 } 119 120 /******************************************************************************* 121 * Platform handler called when a CPU is about to enter standby. ** CID 371991: Control flow issues (NO_EFFECT) /plat/qemu/common/qemu_pm.c: 115 in qemu_validate_ns_entrypoint() ________________________________________________________________________________________________________ *** CID 371991: Control flow issues (NO_EFFECT) /plat/qemu/common/qemu_pm.c: 115 in qemu_validate_ns_entrypoint() 109 { 110 /* 111 * Check if the non secure entrypoint lies within the non 112 * secure DRAM. 113 */ 114 if ((entrypoint >= NS_DRAM0_BASE) && >>> CID 371991: Control flow issues (NO_EFFECT) >>> This less-than-zero comparison of an unsigned value is never true. "entrypoint < 0UL". 115 (entrypoint < (NS_DRAM0_BASE + NS_DRAM0_SIZE))) 116 return PSCI_E_SUCCESS; 117 return PSCI_E_INVALID_ADDRESS; 118 } 119 120 /******************************************************************************* ________________________________________________________________________________________________________ To view the defects in Coverity Scan visit, https://u15810271.ct.sendgrid.net/ls/click?upn=HRESupC-2F2Czv4BOaCWWCy7my0P…

3 years, 2 months

1
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New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware

by scan-admin＠coverity.com

Hi, Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. 1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. New defect(s) Reported-by: Coverity Scan Showing 1 of 1 defect(s) ** CID 364146: Control flow issues (DEADCODE) /plat/mediatek/mt8195/plat_pm.c: 298 in plat_validate_power_state() ________________________________________________________________________________________________________ *** CID 364146: Control flow issues (DEADCODE) /plat/mediatek/mt8195/plat_pm.c: 298 in plat_validate_power_state() 292 { 293 unsigned int pstate = psci_get_pstate_type(power_state); 294 unsigned int aff_lvl = psci_get_pstate_pwrlvl(power_state); 295 unsigned int cpu = plat_my_core_pos(); 296 297 if (aff_lvl > PLAT_MAX_PWR_LVL) { >>> CID 364146: Control flow issues (DEADCODE) >>> Execution cannot reach this statement: "return -2;". 298 return PSCI_E_INVALID_PARAMS; 299 } 300 301 if (pstate == PSTATE_TYPE_STANDBY) { 302 req_state->pwr_domain_state[0] = PLAT_MAX_RET_STATE; 303 } else { ________________________________________________________________________________________________________ To view the defects in Coverity Scan visit, https://u15810271.ct.sendgrid.net/ls/click?upn=HRESupC-2F2Czv4BOaCWWCy7my0P…

3 years, 2 months

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Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages

by Joanna Farley

+ TF-A list that got dropped (again)! Joanna From: Joanna Farley <Joanna.Farley(a)arm.com> Date: Wednesday, 2 June 2021 at 15:29 To: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>, Okash Khawaja <okash.khawaja(a)gmail.com>, Simon Glass <sjg(a)chromium.org> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>, Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>, Ed Stuber <edstuber(a)amperecomputing.com>, Arjun Khare <akhare(a)amperecomputing.com>, U-Boot Mailing List <u-boot(a)lists.denx.de>, Paul Isaac's <paul.isaacs(a)linaro.org>, Ron Minnich <rminnich(a)google.com>, Moe Ammar <moe(a)amperecomputing.com> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages Hi Everyone, The Manish Pandy and Madhukar Pappireddy of the TF-A team are planning to host another TF-A Tech Forum this Thursday to continue the live discussion. Here is their agenda: On tech forum this week, we would like to continue discussions on HOB list design. The topics which we would like to cover is 1. Evaluate different proposals of passing information through boot phases. 2. If we don't get an agreement on one solution fit for all then we would try to get consensus for Infra segment platform(to solve original problem mentioned by Harb) 3. Try to get an agreement on size of tags and how "hybrid and tag only" HOB list can co-exist together? Details of the call are: ====================== TF-A Tech Forum When Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time Calendar tf-a(a)lists.trustedfirmware.org Who • Bill Fletcher- creator • tf-a(a)lists.trustedfirmware.org 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 ================ Joanna On 19/05/2021, 03:50, "Madhukar Pappireddy" <Madhukar.Pappireddy(a)arm.com> wrote: Attached slides presented by Manish in the TF-A tech forum. -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A Sent: Tuesday, May 18, 2021 8:59 PM To: Joanna Farley <Joanna.Farley(a)arm.com>; Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; tf-a(a)lists.trustedfirmware.org; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)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-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A Sent: Sunday, May 16, 2021 5:19 AM To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)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-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)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 <tf-a(a)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 <abdulhamid(a)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.Pandey2(a)arm.com> >> Sent: Friday, April 30, 2021 8:14 AM >> To: François Ozog <francois.ozog(a)linaro.org> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)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_0klgQn… 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 >> >> tf-a(a)lists.trustedfirmware.org >> >> Who >> >> • >> >> Bill Fletcher- creator >> >> • >> >> tf-a(a)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.ozog(a)linaro.org> >> Sent: 08 April 2021 16:50 >> To: Manish Pandey2 <Manish.Pandey2(a)arm.com> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)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_0klgQn… 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 <tf-a(a)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-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org> >> Sent: 25 March 2021 02:43 >> To: Simon Glass <sjg(a)chromium.org> >> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)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/… >> >> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/… >> >> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/… >> >> >> >> 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 <tf-a(a)lists.trustedfirmware.org> wrote: >> >> Hi Harb, >> >> >> >> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)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.ozog(a)linaro.org> >> Sent: Tuesday, March 23, 2021 10:00 AM >> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org> >> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)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 <tf-a(a)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 <sjg(a)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.ozog(a)linaro.org> wrote: >> > >> > +Boot Architecture Mailman List <boot-architecture(a)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 < >> > tf-a(a)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 >> > > TF-A(a)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.ozog(a)linaro.org | Skype: ffozog >> > _______________________________________________ >> > boot-architecture mailing list >> > boot-architecture(a)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.ozog(a)linaro.org | Skype: ffozog >> >> >> >> -- >> TF-A mailing list >> TF-A(a)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.ozog(a)linaro.org | Skype: ffozog >> >> >> >> -- >> TF-A mailing list >> TF-A(a)lists.trustedfirmware.org >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a >> >> -- >> TF-A mailing list >> TF-A(a)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.ozog(a)linaro.org | Skype: ffozog >> >> > > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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