[PATCH 04/13] doc: Add a description for bootmeth_pxe

[Mattijs Korpershoek]

Hi Simon,

Thank you for the patch.

On lun., juil. 15, 2024 at 11:13, Simon Glass <sjg at chromium.org> wrote:

> Add documentation for the pxe bootmeth.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>

Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>

Nitpick: now that pxelinux.rst exist, can we link to this file in
extlinux.rst ?

> ---
>
>  doc/develop/bootstd/index.rst    |  1 +
>  doc/develop/bootstd/overview.rst |  2 +-
>  doc/develop/bootstd/pxelinux.rst | 27 +++++++++++++++++++++++++++
>  3 files changed, 29 insertions(+), 1 deletion(-)
>  create mode 100644 doc/develop/bootstd/pxelinux.rst
>
> diff --git a/doc/develop/bootstd/index.rst b/doc/develop/bootstd/index.rst
> index 5bbb3d633a3..5052afe448f 100644
> --- a/doc/develop/bootstd/index.rst
> +++ b/doc/develop/bootstd/index.rst
> @@ -8,3 +8,4 @@ Standard Boot
>  
>     overview
>     extlinux
> +   pxelinux
> diff --git a/doc/develop/bootstd/overview.rst b/doc/develop/bootstd/overview.rst
> index 086a0b1281d..fd0692daf0d 100644
> --- a/doc/develop/bootstd/overview.rst
> +++ b/doc/develop/bootstd/overview.rst
> @@ -413,7 +413,7 @@ Available bootmeth drivers
>  Bootmeth drivers are provided for:
>  
>     - :doc:`extlinux / syslinux <extlinux>` boot from a disk
> -   - extlinux boot from a network (PXE)
> +   - :doc:`extlinux / syslinux <extlinux>` boot from a network (PXE)
>     - U-Boot scripts from disk, network or SPI flash
>     - EFI boot using bootefi from disk
>     - VBE
> diff --git a/doc/develop/bootstd/pxelinux.rst b/doc/develop/bootstd/pxelinux.rst
> new file mode 100644
> index 00000000000..08ba67e09c5
> --- /dev/null
> +++ b/doc/develop/bootstd/pxelinux.rst
> @@ -0,0 +1,27 @@
> +.. SPDX-License-Identifier: GPL-2.0+:
> +
> +PXE Bootmeth
> +============
> +
> +PXE (Preboot eXecution-Environment) provides a way to boot an Operating System
> +over a network interface. The PXE bootmeth supports PXELINUX and allows U-Boot to
> +provide a menu of possible Operating Systems from which the user can choose.
> +
> +U-Boot includes a parser for the `extlinux.conf` file described
> +`here <https://uapi-group.org/specifications/specs/boot_loader_specification>`_.
> +It consists primarily of a list of named OSes along with the kernel, initial
> +ramdisk and other settings. The file is retrieved from a network server using
> +tftpboot.
> +
> +When invoked on a bootdev, this bootmeth searches for the file and creates a
> +bootflow if found. See
> +`PXELINUX <https://wiki.syslinux.org/wiki/index.php?title=PXELINUX>`_ for
> +a full description of the search procedure.
> +
> +When the bootflow is booted, the bootmeth calls pxe_setup_ctx() to set up the
> +context, then pxe_process() to process the file. Depending on the contents, this
> +may boot an OS or provide a list of options to the user, perhaps with a timeout.
> +
> +The compatible string "u-boot,extlinux-pxe" is used for the driver. The driver
> +is automatically instantiated if there are no bootmeth drivers in the
> +devicetree.
> -- 
> 2.34.1