d75b33af67
Currently, the Linux kernel, libfdt and dtc, when using flattened
device trees encode a node's phandle into a property named
"linux,phandle". The ePAPR specification, however - aiming as it is
to not be a Linux specific spec - requires that phandles be encoded in
a property named simply "phandle".
This patch adds support for this newer approach to dtc and libfdt.
Specifically:
- fdt_get_phandle() will now return the correct phandle if it
is supplied in either of these properties
- fdt_node_offset_by_phandle() will correctly find a node with
the given phandle encoded in either property.
- By default, when auto-generating phandles, dtc will encode
it into both properties for maximum compatibility. A new -H
option allows either only old-style or only new-style
properties to be generated.
- If phandle properties are explicitly supplied in the dts
file, dtc will not auto-generate ones in the alternate format.
- If both properties are supplied, dtc will check that they
have the same value.
- Some existing testcases are updated to use a mix of old and
new-style phandles, partially testing the changes.
- A new phandle_format test further tests the libfdt support,
and the -H option.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
35 lines
764 B
Plaintext
35 lines
764 B
Plaintext
/dts-v1/;
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/ {
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/* Explicit phandles */
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n1: node1 {
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linux,phandle = <0x2000>;
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ref = <&{/node2}>; /* reference precedes target */
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lref = <&n2>;
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};
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n2: node2 {
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phandle = <0x1>;
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ref = <&{/node1}>; /* reference after target */
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lref = <&n1>;
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};
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/* Implicit phandles */
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n3: node3 {
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ref = <&{/node4}>;
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lref = <&n4>;
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};
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n4: node4 {
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};
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/* Explicit phandle with implicit value */
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/* This self-reference is the standard way to tag a node as requiring
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* a phandle (perhaps for reference by nodes that will be dynamically
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* added) without explicitly allocating it a phandle.
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* The self-reference requires some special internal handling, though
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* so check it actually works */
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n5: node5 {
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linux,phandle = <&n5>;
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phandle = <&n5>;
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};
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};
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