29 lines
1.2 KiB
Text
29 lines
1.2 KiB
Text
|
What: /sys/firmware/devicetree/*
|
||
|
|
Date: November 2013
|
||
|
|
Contact: Grant Likely <grant.likely@linaro.org>
|
||
|
|
Description:
|
||
|
|
When using OpenFirmware or a Flattened Device Tree to enumerate
|
||
|
|
hardware, the device tree structure will be exposed in this
|
||
|
|
directory.
|
||
|
|
|
||
|
|
It is possible for multiple device-tree directories to exist.
|
||
|
|
Some device drivers use a separate detached device tree which
|
||
|
|
have no attachment to the system tree and will appear in a
|
||
|
|
different subdirectory under /sys/firmware/devicetree.
|
||
|
|
|
||
|
|
Userspace must not use the /sys/firmware/devicetree/base
|
||
|
|
path directly, but instead should follow /proc/device-tree
|
||
|
|
symlink. It is possible that the absolute path will change
|
||
|
|
in the future, but the symlink is the stable ABI.
|
||
|
|
|
||
|
|
The /proc/device-tree symlink replaces the devicetree /proc
|
||
|
|
filesystem support, and has largely the same semantics and
|
||
|
|
should be compatible with existing userspace.
|
||
|
|
|
||
|
|
The contents of /sys/firmware/devicetree/ is a
|
||
|
|
hierarchy of directories, one per device tree node. The
|
||
|
|
directory name is the resolved path component name (node
|
||
|
|
name plus address). Properties are represented as files
|
||
|
|
in the directory. The contents of each file is the exact
|
||
|
|
binary data from the device tree.
|