Re: [PATCH 5/9] gpu: nova-core: add FSP and PRC protocol documentation

[Alexandre Courbot]

On Wed Jun 17, 2026 at 4:51 PM JST, Zhi Wang wrote:
> On Tue, 16 Jun 2026 17:17:34 +0900
> "Alexandre Courbot" <acourbot@xxxxxxxxxx> wrote:
>
>> On Thu Jun 4, 2026 at 8:43 PM JST, Zhi Wang wrote:
>> > Add documentation for the Foundation Security Processor (FSP)
>> > interface covering the simplified Hopper/Blackwell boot flow, the
>> > Chain of Trust (COT) message protocol, the MCTP/NVDM message
>> > format, and the Product Reconfiguration Control (PRC) protocol used
>> > to query device configuration knobs such as vGPU mode.
>> >
>> > Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx>  
>> 
>> This is super useful, thanks! One question below:
>> 
>> > ---
>> >  Documentation/gpu/nova/core/fsp.rst | 142
>> > ++++++++++++++++++++++++++++ Documentation/gpu/nova/index.rst    |
>> >  1 + 2 files changed, 143 insertions(+)
>> >  create mode 100644 Documentation/gpu/nova/core/fsp.rst
>> >
>> > diff --git a/Documentation/gpu/nova/core/fsp.rst
>> > b/Documentation/gpu/nova/core/fsp.rst new file mode 100644
>> > index 000000000000..52d618d22bb8
>> > --- /dev/null
>> > +++ b/Documentation/gpu/nova/core/fsp.rst
>> > @@ -0,0 +1,142 @@
>> > +.. SPDX-License-Identifier: GPL-2.0
>> > +
>> > +===================================================
>> > +FSP (Foundation Security Processor) and Secure Boot
>> > +===================================================
>> > +This document describes the role of the FSP in the GPU boot
>> > sequence on +Hopper and Blackwell GPUs, and how it differs from the
>> > earlier Ampere boot +flow. It also provides a brief overview of the
>> > PRC (Product Reconfiguration +Control) protocol used to query
>> > device configuration through FSP. As with +other documents in this
>> > directory, the information is subject to change and +is intended to
>> > help developers understand the corresponding kernel code. +
>> > +What is FSP?
>> > +============
>> > +The Foundation Security Processor (FSP) is the GPU's Internal Root
>> > of Trust +(IROT). It is a dedicated security processor that boots
>> > from immutable ROM +(Boot ROM) inside the GPU and is responsible
>> > for establishing the Chain of +Trust before any other firmware is
>> > allowed to run. +
>> > +FSP runs independently of the host CPU and starts executing as
>> > soon as the +GPU is powered on. By the time the nova-core driver is
>> > loaded, FSP has +already completed its own secure boot and is ready
>> > to accept commands from +the driver.
>> > +
>> > +Simplified boot flow (Hopper/Blackwell)
>> > +=======================================
>> > +Starting with Hopper, the boot flow is significantly simplified
>> > compared to +earlier GPU generations like Ampere.
>> > +
>> > +On an **Ampere** GPU, the boot verification chain involves
>> > multiple Falcon +engines and multiple ucode stages (see falcon.rst
>> > for details):: +
>> > +     Hardware BROM (SEC2)  
>> 
>> Is this referring to FWSEC-FRTS? If so, should this be `GSP` instead
>> of `SEC2`?
>
> Hi Alex:
>
> This refers to the BootROM in the SEC2 Peregrine. From the timeline
> perspective, FWSEC-FRTS should be positioned as below. I was thinking to
> show the brief differences of relationship between internal processors
> so I omit the FWSEC-FRTS in the sequence. Do you think we should add it?
>
> +     Hardware BROM (SEC2)
>                     here  < ----- FWSEC-FRTS (GSP)
> +          -> HS Booter (SEC2)
> +               -> LS GSP-RM (GSP)

Ah, I understand now - the boot ROM that verifies the HS Booter. No,
what you wrote makes perfect sense, I just misunderstood.

Pushed as-is to drm-rust-next! Thanks for taking the time to put this
together.