[PATCH] Documentation: devicetree: list automatic boot argument fixups

[PATCH] Documentation: devicetree: list automatic boot argument fixups

[Johannes Zink]

Barebox automatically fixes up several entries to the root and
chosen-node of the devicetree passed to the booted system.

These entries contain information about the hardware, reset source
and the barebox version string.

Add documentation on how to query these information from the booted
linux system.

Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
---
 Documentation/devicetree/index.rst | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst
index 36fa69058d1d..92a91dc35a11 100644
--- a/Documentation/devicetree/index.rst
+++ b/Documentation/devicetree/index.rst
@@ -151,3 +151,24 @@ Contents:
    bindings/regulator/*
    bindings/rtc/*
    bindings/watchdog/*
+
+automatic boot argument fixups to the devicetree
+------------------------------------------------
+
+Barebox automatically fixes up some arguments in the devicetree.
+
+In the devicetree root barebox fixes up
+
+ * serial-number (if available)
+ * machine compatible (if available)
+
+In the ``chosen``-node barebox fixes up
+
+ * barebox-version
+ * reset-source
+ * reset-source-instance (if available)
+ * reset-source-device (phandle, only if available)
+ * bootsource
+ * boot-hartid (only on RISCV)
+
+These values can be read from the booted linux system in ``/proc/device-tree/``.
-- 
2.30.2

Re: [PATCH] Documentation: devicetree: list automatic boot argument fixups

[Ahmad Fatoum]

Hello Johannes,

Thanks for documenting this. Some minor suggestions below.

On 17.03.23 12:07, Johannes Zink wrote:
> Barebox automatically fixes up several entries to the root and

s/entries/properties/

> chosen-node of the devicetree passed to the booted system.

chosen node, device tree

> 
> These entries contain information about the hardware, reset source
> and the barebox version string.
> 
> Add documentation on how to query these information from the booted
> linux system.
> 
> Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
> ---
>  Documentation/devicetree/index.rst | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst
> index 36fa69058d1d..92a91dc35a11 100644
> --- a/Documentation/devicetree/index.rst
> +++ b/Documentation/devicetree/index.rst
> @@ -151,3 +151,24 @@ Contents:
>     bindings/regulator/*
>     bindings/rtc/*
>     bindings/watchdog/*
> +
> +automatic boot argument fixups to the devicetree

Title case or at least a capital letter at the beginning?

> +------------------------------------------------
> +
> +Barebox automatically fixes up some arguments in the devicetree.

s/Barebox/barebox/, s/devicetree/device tree/, s/arguments/properties/
or information.

> +
> +In the devicetree root barebox fixes up

, barebox

> +
> + * serial-number (if available)
> + * machine compatible (if available)

s/available/overridden/
There's nearly always a machine compatible.

> +
> +In the ``chosen``-node barebox fixes up

, barebox

> +
> + * barebox-version
> + * reset-source
> + * reset-source-instance (if available)
> + * reset-source-device (phandle, only if available)

node path, not the numeric phandle, compare

 property = &path -> "/path/to/something"

vs.

 property = <&path> -> <0x23>, with &path { phandle = <0x23>; }

> + * bootsource
> + * boot-hartid (only on RISCV)

RISC-V

> +
> +These values can be read from the booted linux system in ``/proc/device-tree/`

"or /sys/firmware/devicetree/base".


Thanks,
Ahmad

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