26853a2420
- Add a SPDX header; - Adjust document title; - Add it to devicetree/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org>
28 lines
1.1 KiB
ReStructuredText
28 lines
1.1 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
==================================
|
|
Device Tree Dynamic Resolver Notes
|
|
==================================
|
|
|
|
This document describes the implementation of the in-kernel
|
|
Device Tree 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.
|