forked from Qortal/Brooklyn
32 lines
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
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Howto use the configfs overlay interface.
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A device-tree configfs entry is created in /config/device-tree/overlays
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and and it is manipulated using standard file system I/O.
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Note that this is a debug level interface, for use by developers and
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not necessarily something accessed by normal users due to the
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security implications of having direct access to the kernel's device tree.
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* To create an overlay you mkdir the directory:
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# mkdir /config/device-tree/overlays/foo
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* Either you echo the overlay firmware file to the path property file.
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# echo foo.dtbo >/config/device-tree/overlays/foo/path
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* Or you cat the contents of the overlay to the dtbo file
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# cat foo.dtbo >/config/device-tree/overlays/foo/dtbo
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The overlay file will be applied, and devices will be created/destroyed
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as required.
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To remove it simply rmdir the directory.
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# rmdir /config/device-tree/overlays/foo
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The rationalle of the dual interface (firmware & direct copy) is that each is
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better suited to different use patterns. The firmware interface is what's
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intended to be used by hardware managers in the kernel, while the copy interface
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make sense for developers (since it avoids problems with namespaces).
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