[PATCH v2 10/11] doc: arm64: document FF-A runtime path for EFI variables

[Simon Glass]

Hi Harsimran,

On 2026-05-14T12:49:13, Harsimran Singh Tungal
<harsimransingh.tungal at arm.com> wrote:
> doc: arm64: document FF-A runtime path for EFI variables
>
> The arm64 FF-A documentation still said EFI runtime support was a
> future development, so readers had no description of the current FF-A
> runtime transport or how EFI runtime variable services use it.
>
> Document the FF-A runtime transport, the shared MM communication path,
> and the EFI runtime variable flow on arm64. Also clarify that the
> armffa command is boot-time only and point readers to the architecture
> documentation for EFI runtime variable services over FF-A.
>
> Acked-by: Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
> Signed-off-by: Harsimran Singh Tungal <harsimransingh.tungal at arm.com>
>
> doc/arch/arm64.ffa.rst   | 86 ++++++++++++++++++++++++++++++++++++++++++++----
>  doc/usage/cmd/armffa.rst | 11 +++++++
>  2 files changed, 90 insertions(+), 7 deletions(-)

> diff --git a/doc/arch/arm64.ffa.rst b/doc/arch/arm64.ffa.rst
> @@ -158,6 +164,71 @@ they want to use (32-bit vs 64-bit). Selecting the protocol means using
> +At runtime, the driver model is no longer available. Runtime users should
> +use the resident FF-A runtime transport, which verifies the runtime context
> +before issuing FF-A calls.

Please name the actual API the runtime user is expected to call (the
helpers from include/arm_ffa_runtime.h), otherwise the reader is told
to use the resident runtime transport without being pointed at the
entry points.

Reviewed-by: Simon Glass <sjg at chromium.org>

Regards,
Simon