[PATCH v2 4/4] smbios: Add documentation and devicetree binding

[Simon Glass]

Hi Heinrich,

On Fri, 2 Oct 2020 at 08:57, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 02.10.20 16:23, Simon Glass wrote:
> > Add information about how to set SMBIOS properties using the devicetree.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> > (no changes since v1)
> >
> >  doc/arch/x86.rst                             |  8 +++++
> >  doc/device-tree-bindings/board/board_x86.txt | 36 ++++++++++++++++++++
> >  2 files changed, 44 insertions(+)
> >  create mode 100644 doc/device-tree-bindings/board/board_x86.txt
> >
> > diff --git a/doc/arch/x86.rst b/doc/arch/x86.rst
> > index c6b70ce61a3..45f9ba308c7 100644
> > --- a/doc/arch/x86.rst
> > +++ b/doc/arch/x86.rst
> > @@ -740,6 +740,14 @@ Note that this is a development feature only. It is not intended for use in
> >  production environments. Also it is not currently part of the automated tests
> >  so may break in the future.
> >
> > +SMBIOS tables
> > +-------------
> > +
> > +To generate SMBIOS tables in U-Boot, for use by the OS, enable the
> > +CONFIG_GENERATE_SMBIOS_TABLE option. The easiest way to provide the values to
> > +use is via the device tree. For details see
> > +device-tree-bindings/board/board_x86.txt
> > +
> >  TODO List
> >  ---------
> >  - Audio
> > diff --git a/doc/device-tree-bindings/board/board_x86.txt b/doc/device-tree-bindings/board/board_x86.txt
> > new file mode 100644
> > index 00000000000..3766751896a
> > --- /dev/null
> > +++ b/doc/device-tree-bindings/board/board_x86.txt
> > @@ -0,0 +1,36 @@
> > +x86 board driver
> > +================
> > +
> > +This driver allows providing board-specific features such as power control
> > +GPIOs. In addition, the SMBIOS values can be specified in the device tree,
> > +as below:
> > +
> > +An optional 'smbios' subnode can be used to provide these properties.
> > +
> > +Optional properties:
> > +  - manufacturer: Product manufacturer for system / baseboard
> > +  - product:      Product name
> > +  - version:      Product version string
> > +  - serial:       Serial number for system (note that this can be overridden by
> > +                      the serial# environment variable)
> > +  - sku:          Product SKU (Stock-Keeping Unit)
> > +  - family:       Product family
> > +  - asset-tag:    Asset tag for the motherboard, sometimes used in organisations
> > +                      to track devices
> > +
> > +
> > +Example:
> > +
> > +     board {
> > +             compatible = "google,coral";
> > +
> > +             smbios {
>
> I think board is the wrong place for the new node.
>
> SMBIOS also includes chassis, processor and other information. We may
> opt to provide non-board information in future via the device-tree.

I think of board as the whole thing. Are you thinking of it just being
the circuit board?

>
> If this is for U-Boot internal only usage, we should indicate this in
> the label name.

All drivers are for U-Boot-internal use, right? Or are you saying you
don't want this information to appear in the upstream bindings?

>
> So it could be like:
>
> /u-boot-smbios {

compatible string?

>    bios {};
>    system {};
>    board {
>       manufacturer = "Hardkernel Co., Ltd.";
>       product = "ODROID-C2";
>       ...
>    };
>    chassis {};
>    processor {};
>    boot {};
> };
>
> > +                     manufacturer = "Google";
> > +                     product = "Coral";
> > +                     version = "rev2";
> > +                     serial = "123456789";
> > +                     sku = "sku3";
> > +                     family = "Google_Coral";
> > +                     asset-tag = "ABC123";
> > +             };
> > +     };
> >
>
> SMBIOS is not x86 specific. On ARM we are also passing an SMBIOS table.
>
> On my Odroid C2 dmidecode shows the information provided by U-Boot:

Oh dear. Legacy never dies. It never occurred to me that this would be
used on ARM.

>
> ....
> Handle 0x0001, DMI type 1, 27 bytes
> System Information
>         Manufacturer: Hardkernel Co., Ltd.
>         Product Name: ODROID-C2
>         Version: Not Specified
> ...
>         Wake-up Type: Reserved
>         SKU Number: Not Specified
>         Family: Not Specified
> ....
>
>
> So doc/device-tree-bindings/board/board_x86.txt is the wrong place to
> document the new device tree node.
>
> Why not create a document doc/device-tree-bindings/smbios.rst for it?

OK I can do that. I'll await your thoughts on the above.

Regards,
Simon