u-boot/doc/device-tree-bindings/bootstd.txt

U-Boot standard boot device (bootstd)
=====================================

This is the controlling device for U-Boot standard boot, providing a way to
boot operating systems in a way that can be controlled by distros.

Required properties:

compatible: "u-boot,boot-std"

Optional properties:

filename-prefixes:
   List of strings, each a directory to search for bootflow files

bootdev-order:
   List of bootdevs to check for bootflows, each a bootdev label (the media
   uclass followed by the numeric sequence number of the media device)


Example:

	bootstd {
		compatible = "u-boot,boot-std";

		filename-prefixes = "/", "/boot/";
		bootdev-order = "mmc2", "mmc1";

		extlinux {
			compatible = "u-boot,extlinux";
		};

		efi {
			compatible = "u-boot,distro-efi";
		};
	};