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Diffstat (limited to 'doc/develop/bootstd/pxelinux.rst')
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diff --git a/doc/develop/bootstd/pxelinux.rst b/doc/develop/bootstd/pxelinux.rst new file mode 100644 index 00000000000..c4b7fbb4c9c --- /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 operating systems along with the +kernel, initial ramdisk and other settings. The file is retrieved from a network +server using the TFTP protocol. + +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 Operating System 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. It is +present if `CONFIG_BOOTMETH_EXTLINUX_PXE` is enabled. |