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| 3 | =================================
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| 4 | Devicetree Dynamic Resolver Notes
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| 5 | =================================
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| 6 |
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| 7 | This document describes the implementation of the in-kernel
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| 8 | DeviceTree resolver, residing in drivers/of/resolver.c
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| 9 |
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| 10 | How the resolver works
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| 11 | ----------------------
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| 12 |
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| 13 | The resolver is given as an input an arbitrary tree compiled with the
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| 14 | proper dtc option and having a /plugin/ tag. This generates the
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| 15 | appropriate __fixups__ & __local_fixups__ nodes.
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| 16 |
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| 17 | In sequence the resolver works by the following steps:
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| 18 |
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| 19 | 1. Get the maximum device tree phandle value from the live tree + 1.
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| 20 | 2. Adjust all the local phandles of the tree to resolve by that amount.
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| 21 | 3. Using the __local__fixups__ node information adjust all local references
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| 22 | by the same amount.
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| 23 | 4. For each property in the __fixups__ node locate the node it references
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| 24 | in the live tree. This is the label used to tag the node.
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| 25 | 5. Retrieve the phandle of the target of the fixup.
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| 26 | 6. For each fixup in the property locate the node:property:offset location
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| 27 | and replace it with the phandle value.
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