2020-04-15 22:45:20 +08:00
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.. SPDX-License-Identifier: GPL-2.0
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2021-03-26 00:47:09 +08:00
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=================================
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Devicetree Dynamic Resolver Notes
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=================================
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2014-07-05 00:59:20 +08:00
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This document describes the implementation of the in-kernel
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2021-03-26 00:47:09 +08:00
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DeviceTree resolver, residing in drivers/of/resolver.c
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2014-07-05 00:59:20 +08:00
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How the resolver works
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----------------------
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The resolver is given as an input an arbitrary tree compiled with the
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proper dtc option and having a /plugin/ tag. This generates the
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2018-07-19 19:54:04 +08:00
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appropriate __fixups__ & __local_fixups__ nodes.
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2014-07-05 00:59:20 +08:00
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In sequence the resolver works by the following steps:
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1. Get the maximum device tree phandle value from the live tree + 1.
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2. Adjust all the local phandles of the tree to resolve by that amount.
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3. Using the __local__fixups__ node information adjust all local references
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by the same amount.
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4. For each property in the __fixups__ node locate the node it references
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in the live tree. This is the label used to tag the node.
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5. Retrieve the phandle of the target of the fixup.
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6. For each fixup in the property locate the node:property:offset location
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and replace it with the phandle value.
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