[PATCH] doc: booting-linux: improve bootspec chapter

[Sascha Hauer]

On Fri, Oct 06, 2023 at 11:24:05AM +0200, Roland Hieber wrote:
> * use the official name of the spec in the title
> * transform the URL to a link with title
> * mention other well-known search terms (e.g. "blspec", which is used in
>   PTXdist, and "bootspec", which is often used by my colleagues)
> * don't highlight the scripts/kernel-install output as shell code
> * keep the NFS boot paragraph near the SD boot paragraph
> * format 'machine-id' and 'linux-appendroot' explanations as definition
>   lists so they are easily found when looking for them
> * pick some more low-hanging formatting and copy editing fruits (it's
>   harvest season after all)
> 
> Signed-off-by: Roland Hieber <rhi at pengutronix.de>
> ---
>  Documentation/user/booting-linux.rst | 43 ++++++++++++++++------------
>  1 file changed, 24 insertions(+), 19 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/Documentation/user/booting-linux.rst b/Documentation/user/booting-linux.rst
> index 76883862b938..b26ada943a59 100644
> --- a/Documentation/user/booting-linux.rst
> +++ b/Documentation/user/booting-linux.rst
> @@ -163,12 +163,12 @@ setting the ``global.boot.default`` variable to ``mmc`` and then calling
>  
>  .. _bootloader_spec:
>  
> -Bootloader Spec
> -^^^^^^^^^^^^^^^
> +Boot Loader Specification
> +^^^^^^^^^^^^^^^^^^^^^^^^^
>  
> -barebox supports booting according to the bootloader spec:
> -
> -https://uapi-group.org/specifications/specs/boot_loader_specification/
> +barebox supports booting according to the `Boot Loader Specification
> +<https://uapi-group.org/specifications/specs/boot_loader_specification/>`__
> +(sometimes also known as *Bootloader Spec*, *bootspec* or *blspec*).
>  
>  It follows another philosophy than the :ref:`boot_entries`. With Boot Entries
>  booting is completely configured in the bootloader. Bootloader Spec Entries
> @@ -209,7 +209,7 @@ Spec Entry on a SD card:
>  
>  The entry can be listed with the ``-l`` option:
>  
> -.. code-block:: sh
> +.. code-block:: none
>  
>    scripts/kernel-install --device=/dev/mmcblk0 -l
>  
> @@ -223,24 +223,29 @@ The entry can be listed with the ``-l`` option:
>  When the SD card shows up as ``mmc1`` in barebox, this entry can be booted with
>  ``boot mmc1`` or by setting ``global.boot.default`` to ``mmc1``.
>  
> -``machine-id`` is an optional key. If the ``global.boot.machine_id`` variable
> -is set to a non-empty value, barebox will only boot the Bootloader Spec Entry
> -whose ``machine-id`` key matches the ``global.boot.machine_id`` variable.
> -All other Bootloader Spec entries will be ignored.
> -
> -A bootloader spec entry can also reside on an NFS server in which case an
> -RFC2224-compatible NFS URI string must be passed to the boot command:
> +A bootloader spec entry can also reside on an NFS server, in which case an
> +`RFC 2224 <https://datatracker.ietf.org/doc/html/rfc2224>`__-compatible NFS URI
> +must be passed to the boot command:
>  
>  .. code-block:: sh
>  
>    boot nfs://nfshost[:port]//path/
>  
> -In addition to the options defined in the original spec barebox understands the
> -``linux-appendroot`` option. This is a boolean value and if set to ``true`` barebox
> -will automatically append a ``root=`` string to the Linux commandline based on the
> -device where the entry is found on. This makes it possible to use the same rootfs
> -image on different devices without having to specify a different root= option each
> -time.
> +Additional notes about keys in the bootloader spec entries:
> +
> +``machine-id``
> +   This key is optional. If the ``global.boot.machine_id`` variable is set to a
> +   non-empty value, barebox will only boot the Bootloader Spec Entry whose
> +   ``machine-id`` key matches the ``global.boot.machine_id`` variable.  All
> +   other Bootloader Spec entries will be ignored.
> +
> +``linux-appendroot``
> +   This boolean option is understood by Barebox although it is not part of the
> +   original specification. If set to ``true``, barebox will automatically append
> +   a ``root=`` string to the Linux commandline based on the device where the
> +   entry is found on. This makes it possible to use the same rootfs image on
> +   different devices without having to specify a different ``root=`` option each
> +   time.
>  
>  .. _booting_linux_net:
>  
> -- 
> 2.39.2
> 
> 
> 

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