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Diffstat (limited to 'Documentation/ABI/testing/sysfs-firmware-ofw')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-ofw | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw new file mode 100644 index 00000000000..f562b188e71 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-ofw @@ -0,0 +1,28 @@ +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. |