[PATCH v5 4/4] Documentation: ABI: /sys/firmware/devicetree/overlays

From: Pantelis Antoniou
Date: Wed Sep 16 2015 - 12:09:34 EST


Documentation ABI entry for overlays sysfs entries.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
.../ABI/testing/sysfs-firmware-devicetree-overlays | 35 ++++++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-firmware-devicetree-overlays

diff --git a/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays b/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays
new file mode 100644
index 0000000..2166051
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays
@@ -0,0 +1,35 @@
+What: /sys/firmware/devicetree/overlays/
+Date: March 2015
+Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
+Description:
+ This directory contains the applied device tree overlays of
+ the running system, as directories of the overlay id.
+
+ enable: The master enable switch, by default is 1, and when
+ set to 0 it cannot be re-enabled for security reasons.
+
+ The discussion about this switch takes place in:
+ http://comments.gmane.org/gmane.linux.drivers.devicetree/101871
+
+ Kees Cook:
+ "Coming from the perspective of drawing a bright line between
+ kernel and the root user (which tends to start with disabling
+ kernel module loading), I would say that there at least needs
+ to be a high-level one-way "off" switch for the interface so
+ that systems that have this interface can choose to turn it off
+ during initial boot, etc."
+
+What: /sys/firmware/devicetree/overlays/<id>
+Date: March 2015
+Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
+Description:
+ Each directory represents an applied overlay, containing
+ the following attribute files.
+
+ targets: A file containing the list of targets of each overlay
+ with each line containing a target.
+
+ can_remove: The attribute set to 1 means that the overlay can
+ be removed, while 0 means that the overlay is being
+ overlapped therefore removal is prohibited.
+
--
1.7.12

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/