bootstd: Add the bootstd uclass and core implementation

The 'bootstd' device provides the central information about U-Boot
standard boot.

Add a uclass for bootstd and the various helpers needed to make it
work. Also add a binding file.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/doc/device-tree-bindings/bootstd.txt b/doc/device-tree-bindings/bootstd.txt
new file mode 100644
index 00000000000..f048b9dd327
--- /dev/null
+++ b/doc/device-tree-bindings/bootstd.txt
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+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";
+	};