| .. SPDX-License-Identifier: GPL-2.0+: | |
| Extlinux Bootmeth | |
| ================= | |
| `Extlinux <https://uapi-group.org/specifications/specs/boot_loader_specification>`_ | |
| (sometimes called syslinux) allows U-Boot to provide a menu of available | |
| operating systems from which the user can choose. | |
| U-Boot includes a parser for the `extlinux.conf` file. It consists primarily of | |
| a list of named operating systems along with the kernel, initial ramdisk and | |
| other settings. The file is stored in the `extlinux/` subdirectory, possibly | |
| under the `boot/` subdirectory. This list of prefixes (``{"/", "/boot"}`` by | |
| default) can be selected with the `filename-prefixes` property in the bootstd | |
| device. | |
| Note that the :doc:`pxelinux` uses the same file format, but in a | |
| network context. | |
| When invoked on a bootdev, this bootmeth searches for the file and creates a | |
| bootflow if found. | |
| 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" is used for the driver. It is present | |
| if `CONFIG_BOOTMETH_EXTLINUX` is enabled. |