Re: [PATCH v2 4/4] x86: Add qemu documentation for running as flash binary

Hi Elliot,

On 2026-08-07T18:07:09, Elliot Berman <[email protected]> wrote:
> x86: Add qemu documentation for running as flash binary
>
> Provide guidance for testing capsule updates on x86/x86_64.
>
> Signed-off-by: Elliot Berman <[email protected]>
>
> doc/board/emulation/qemu-x86.rst | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)

>     Provide guidance for testing capsule updates on x86/x86_64.

The section stops after launching QEMU, so it does not show how to
test a capsule update. Please can you add the remaining steps -
generating a capsule with mkeficapsule using the GUIDs from patch 2
and applying it via capsule-on-disk - or at least reference the
capsule-update section in doc/develop/uefi/uefi.rst?

> diff --git a/doc/board/emulation/qemu-x86.rst b/doc/board/emulation/qemu-x86.rst
> @@ -113,6 +113,23 @@ sure the specified CPU supports 64-bit like '-cpu core2duo'. Conversely
> +Invoke QEMU with:
> +
> +.. code-block:: bash
> +
> +   qemu-system-x86_64 -drive if=pflash,format=raw,file=path/to/u-boot.rom,readonly=off

The rest of this file uses plain '::' literal blocks with a '$ '
prefix for commands - do you want to match that style? It would also
help to say that -drive if=pflash replaces the -bios option used
elsewhere in the document, since that is the key difference here, and
that qemu-system-i386 is used for the 32-bit build, matching the
earlier examples.

> diff --git a/doc/board/emulation/qemu-x86.rst b/doc/board/emulation/qemu-x86.rst
> @@ -113,6 +113,23 @@ sure the specified CPU supports 64-bit like '-cpu core2duo'. Conversely
> +To create a U-Boot binary that can accept capsule updates, build
> +qemu-x86_64_defconfig or qemu-x86_defconfig with::

Just to check, is CONFIG_EFI_RUNTIME_UPDATE_CAPSULE actually needed?
Capsule-on-disk works without the runtime UpdateCapsule() service, so
if the intent is just the on-disk flow it could be dropped. If it is
needed, a brief note on why would help the reader.

Regards,
Simon