From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- .../devicetree/dynamic-resolution-notes.rst | 27 ++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 Documentation/devicetree/dynamic-resolution-notes.rst (limited to 'Documentation/devicetree/dynamic-resolution-notes.rst') diff --git a/Documentation/devicetree/dynamic-resolution-notes.rst b/Documentation/devicetree/dynamic-resolution-notes.rst new file mode 100644 index 000000000..f81ad8daa --- /dev/null +++ b/Documentation/devicetree/dynamic-resolution-notes.rst @@ -0,0 +1,27 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================= +Devicetree Dynamic Resolver Notes +================================= + +This document describes the implementation of the in-kernel +DeviceTree resolver, residing in drivers/of/resolver.c + +How the resolver works +---------------------- + +The resolver is given as an input an arbitrary tree compiled with the +proper dtc option and having a /plugin/ tag. This generates the +appropriate __fixups__ & __local_fixups__ nodes. + +In sequence the resolver works by the following steps: + +1. Get the maximum device tree phandle value from the live tree + 1. +2. Adjust all the local phandles of the tree to resolve by that amount. +3. Using the __local__fixups__ node information adjust all local references + by the same amount. +4. For each property in the __fixups__ node locate the node it references + in the live tree. This is the label used to tag the node. +5. Retrieve the phandle of the target of the fixup. +6. For each fixup in the property locate the node:property:offset location + and replace it with the phandle value. -- cgit v1.2.3