Merge branch '2022-08-11-verified-boot-for-embedded-initial-support'

To quote Simon:
This adds the concept of a VBE method to U-Boot, along with an
implementation of the 'VBE simple' method, basically a simple way of
updating firmware in MMC from userspace and monitoring it from U-Boot.

VBE simple is implemented in fwupd. U-Boot's role is to set up the
device tree with the required firmware-update properties and provide the
developer with information about the current VBE state. To that end this
series includes a new 'vbe' command that allows VBE methods to be listed
and examined.

As part of this work, support for doing FDT fixups via the event interface
is provided, along with the ability to write to the device tree via the
ofnode interface.

Another (significant) change is that bootmeths now have a 'global' flag,
to allow the implementation of EFI bootmgr (and VBE) to be cleaned up.
The 'system' bootdev is no-longer needed and these bootmeths are scanned
first.

Further work is needed to pull everything together, but this is a step
along the way.

1 files changed, 85 insertions, 0 deletions

diff --git a/include/dm/ofnode_decl.h b/include/dm/ofnode_decl.h
new file mode 100644
index 00000000000..266253d5e33
--- /dev/null
+++ b/include/dm/ofnode_decl.h
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#ifndef _DM_OFNODE_DECL_H
+#define _DM_OFNODE_DECL_H
+
+/**
+ * typedef union ofnode_union ofnode - reference to a device tree node
+ *
+ * This union can hold either a straightforward pointer to a struct device_node
+ * in the live device tree, or an offset within the flat device tree. In the
+ * latter case, the pointer value is just the integer offset within the flat DT.
+ *
+ * Thus we can reference nodes in both the live tree (once available) and the
+ * flat tree (until then). Functions are available to translate between an
+ * ofnode and either an offset or a `struct device_node *`.
+ *
+ * The reference can also hold a null offset, in which case the pointer value
+ * here is NULL. This corresponds to a struct device_node * value of
+ * NULL, or an offset of -1.
+ *
+ * There is no ambiguity as to whether ofnode holds an offset or a node
+ * pointer: when the live tree is active it holds a node pointer, otherwise it
+ * holds an offset. The value itself does not need to be unique and in theory
+ * the same value could point to a valid device node or a valid offset. We
+ * could arrange for a unique value to be used (e.g. by making the pointer
+ * point to an offset within the flat device tree in the case of an offset) but
+ * this increases code size slightly due to the subtraction. Since it offers no
+ * real benefit, the approach described here seems best.
+ *
+ * For now these points use constant types, since we don't allow writing
+ * the DT.
+ *
+ * @np: Pointer to device node, used for live tree
+ * @of_offset: Pointer into flat device tree, used for flat tree. Note that this
+ *	is not a really a pointer to a node: it is an offset value. See above.
+ */
+typedef union ofnode_union {
+	const struct device_node *np;
+	long of_offset;
+} ofnode;
+
+/**
+ * struct ofprop - reference to a property of a device tree node
+ *
+ * This struct hold the reference on one property of one node,
+ * using struct ofnode and an offset within the flat device tree or either
+ * a pointer to a struct property in the live device tree.
+ *
+ * Thus we can reference arguments in both the live tree and the flat tree.
+ *
+ * The property reference can also hold a null reference. This corresponds to
+ * a struct property NULL pointer or an offset of -1.
+ *
+ * @node: Pointer to device node
+ * @offset: Pointer into flat device tree, used for flat tree.
+ * @prop: Pointer to property, used for live treee.
+ */
+
+struct ofprop {
+	ofnode node;
+	union {
+		int offset;
+		const struct property *prop;
+	};
+};
+
+/**
+ * union oftree_union - reference to a tree of device tree nodes
+ *
+ * One or other of the members is used, depending on of_live_active()
+ *
+ * @np: Pointer to roott device node, used for live tree
+ * @fdt: Pointer to the flat device tree, used for flat tree
+ */
+typedef union oftree_union {
+	struct device_node *np;
+	void *fdt;
+} oftree;
+
+#endif
+