From 26853a242057b8c09f51726b54a79aff3fec874a Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 15 Apr 2020 16:45:20 +0200 Subject: docs: dt: convert dynamic-resolution-notes.txt to ReST - Add a SPDX header; - Adjust document title; - Add it to devicetree/index.rst. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Rob Herring --- .../devicetree/dynamic-resolution-notes.rst | 27 ++++++++++++++++++++++ .../devicetree/dynamic-resolution-notes.txt | 24 ------------------- Documentation/devicetree/index.rst | 1 + Documentation/devicetree/overlay-notes.txt | 2 +- MAINTAINERS | 2 +- 5 files changed, 30 insertions(+), 26 deletions(-) create mode 100644 Documentation/devicetree/dynamic-resolution-notes.rst delete mode 100644 Documentation/devicetree/dynamic-resolution-notes.txt diff --git a/Documentation/devicetree/dynamic-resolution-notes.rst b/Documentation/devicetree/dynamic-resolution-notes.rst new file mode 100644 index 000000000000..570b7e1f39eb --- /dev/null +++ b/Documentation/devicetree/dynamic-resolution-notes.rst @@ -0,0 +1,27 @@ +.. 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. diff --git a/Documentation/devicetree/dynamic-resolution-notes.txt b/Documentation/devicetree/dynamic-resolution-notes.txt deleted file mode 100644 index c24ec366c5dc..000000000000 --- a/Documentation/devicetree/dynamic-resolution-notes.txt +++ /dev/null @@ -1,24 +0,0 @@ -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. diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst index a9757ec5070e..d3183b33c2e9 100644 --- a/Documentation/devicetree/index.rst +++ b/Documentation/devicetree/index.rst @@ -10,3 +10,4 @@ Open Firmware and Device Tree usage-model writing-schema changesets + dynamic-resolution-notes diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt index fddc63da7dba..b06ffcb8f0f8 100644 --- a/Documentation/devicetree/overlay-notes.txt +++ b/Documentation/devicetree/overlay-notes.txt @@ -3,7 +3,7 @@ Device Tree Overlay Notes This document describes the implementation of the in-kernel device tree overlay functionality residing in drivers/of/overlay.c and is a -companion document to Documentation/devicetree/dynamic-resolution-notes.txt[1] +companion document to Documentation/devicetree/dynamic-resolution-notes.rst[1] How overlays work ----------------- diff --git a/MAINTAINERS b/MAINTAINERS index ca79391d3ff0..03a1abf0d6e9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12535,7 +12535,7 @@ M: Pantelis Antoniou M: Frank Rowand L: devicetree@vger.kernel.org S: Maintained -F: Documentation/devicetree/dynamic-resolution-notes.txt +F: Documentation/devicetree/dynamic-resolution-notes.rst F: Documentation/devicetree/overlay-notes.txt F: drivers/of/overlay.c F: drivers/of/resolver.c -- cgit v1.2.3-59-g8ed1b